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Tian X, Janes HE, Kublin JG. Statistical design and analysis of controlled human malaria infection trials. Malar J 2024; 23:133. [PMID: 38702775 PMCID: PMC11068571 DOI: 10.1186/s12936-024-04959-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 04/22/2024] [Indexed: 05/06/2024] Open
Abstract
BACKGROUND Malaria is a potentially life-threatening disease caused by Plasmodium protozoa transmitted by infected Anopheles mosquitoes. Controlled human malaria infection (CHMI) trials are used to assess the efficacy of interventions for malaria elimination. The operating characteristics of statistical methods for assessing the ability of interventions to protect individuals from malaria is uncertain in small CHMI studies. This paper presents simulation studies comparing the performance of a variety of statistical methods for assessing efficacy of intervention in CHMI trials. METHODS Two types of CHMI designs were investigated: the commonly used single high-dose design (SHD) and the repeated low-dose design (RLD), motivated by simian immunodeficiency virus (SIV) challenge studies. In the context of SHD, the primary efficacy endpoint is typically time to infection. Using a continuous time survival model, five statistical tests for assessing the extent to which an intervention confers partial or full protection under single dose CHMI designs were evaluated. For RLD, the primary efficacy endpoint is typically the binary infection status after a specific number of challenges. A discrete time survival model was used to study the characteristics of RLD versus SHD challenge studies. RESULTS In a SHD study with the continuous time survival model, log-rank test and t-test are the most powerful and provide more interpretable results than Wilcoxon rank-sum tests and Lachenbruch tests, while the likelihood ratio test is uniformly most powerful but requires knowledge of the underlying probability model. In the discrete time survival model setting, SHDs are more powerful for assessing the efficacy of an intervention to prevent infection than RLDs. However, additional information can be inferred from RLD challenge designs, particularly using a likelihood ratio test. CONCLUSIONS Different statistical methods can be used to analyze controlled human malaria infection (CHMI) experiments, and the choice of method depends on the specific characteristics of the experiment, such as the sample size allocation between the control and intervention groups, and the nature of the intervention. The simulation results provide guidance for the trade off in statistical power when choosing between different statistical methods and study designs.
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Affiliation(s)
- Xiaowen Tian
- Department of Biostatistics, University of Washington, 3980 15th Ave NE, Seattle, WA, 98195, USA.
| | - Holly E Janes
- Department of Biostatistics, University of Washington, 3980 15th Ave NE, Seattle, WA, 98195, USA
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, 1100 Fairview Ave N, Seattle, WA, 98109, USA
| | - James G Kublin
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, 1100 Fairview Ave N, Seattle, WA, 98109, USA
- Department of Global Health, University of Washington, 3980 15th Ave NE, Seattle, WA, 98195, USA
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Rajneesh, Tiwari R, Singh VK, Kumar A, Gupta RP, Singh AK, Gautam V, Kumar R. Advancements and Challenges in Developing Malaria Vaccines: Targeting Multiple Stages of the Parasite Life Cycle. ACS Infect Dis 2023; 9:1795-1814. [PMID: 37708228 DOI: 10.1021/acsinfecdis.3c00332] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023]
Abstract
Malaria, caused by Plasmodium species, remains a major global health concern, causing millions of deaths annually. While the introduction of the RTS,S vaccine has shown promise, there is a pressing need for more effective vaccines due to the emergence of drug-resistant parasites and insecticide-resistant vectors. However, the complex life cycle and genetic diversity of the parasite, technical obstacles, limited funding, and the impact of the 2019 pandemic have hindered progress in malaria vaccine development. This review focuses on advancements in malaria vaccine development, particularly the ongoing clinical trials targeting antigens from different stages of the Plasmodium life cycle. Additionally, we discuss the rationale, strategies, and challenges associated with vaccine design, aiming to enhance the immune response and protective efficacy of vaccine candidates. A cost-effective and multistage vaccine could hold the key to controlling and eradicating malaria.
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Affiliation(s)
- Rajneesh
- Centre of Experimental Medicine & Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Rahul Tiwari
- Centre of Experimental Medicine & Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Vishal K Singh
- Centre of Experimental Medicine & Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Awnish Kumar
- Centre of Experimental Medicine & Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Rohit P Gupta
- Centre of Experimental Medicine & Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
- Department of Applied Microbiology, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Akhilesh K Singh
- Faculty of Dental Science, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Vibhav Gautam
- Centre of Experimental Medicine & Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Rajiv Kumar
- Centre of Experimental Medicine & Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
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Patterns of Heterochromatin Transitions Linked to Changes in the Expression of Plasmodium falciparum Clonally Variant Genes. Microbiol Spectr 2023; 11:e0304922. [PMID: 36515553 PMCID: PMC9927496 DOI: 10.1128/spectrum.03049-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The survival of malaria parasites in the changing human blood environment largely depends on their ability to alter gene expression by epigenetic mechanisms. The active state of Plasmodium falciparum clonally variant genes (CVGs) is associated with euchromatin characterized by the histone mark H3K9ac, whereas the silenced state is characterized by H3K9me3-based heterochromatin. Expression switches are linked to euchromatin-heterochromatin transitions, but these transitions have not been characterized for the majority of CVGs. To define the heterochromatin distribution patterns associated with the alternative transcriptional states of CVGs, we compared H3K9me3 occupancy at a genome-wide level among several parasite subclones of the same genetic background that differed in the transcriptional state of many CVGs. We found that de novo heterochromatin formation or the complete disruption of a heterochromatin domain is a relatively rare event, and for the majority of CVGs, expression switches can be explained by the expansion or retraction of heterochromatin domains. We identified different modalities of heterochromatin changes linked to transcriptional differences, but despite this complexity, heterochromatin distribution patterns generally enable the prediction of the transcriptional state of specific CVGs. We also found that in some subclones, several var genes were simultaneously in an active state. Furthermore, the heterochromatin levels in the putative regulatory region of the gdv1 antisense noncoding RNA, a regulator of sexual commitment, varied between parasite lines with different sexual conversion rates. IMPORTANCE The malaria parasite P. falciparum is responsible for more than half a million deaths every year. P. falciparum clonally variant genes (CVGs) mediate fundamental host-parasite interactions and play a key role in parasite adaptation to fluctuations in the conditions of the human host. The expression of CVGs is regulated at the epigenetic level by changes in the distribution of a type of chromatin called heterochromatin. Here, we describe at a genome-wide level the changes in the heterochromatin distribution associated with the different transcriptional states of CVGs. Our results also reveal a likely role for heterochromatin at a particular locus in determining the parasite investment in transmission to mosquitoes. Additionally, this data set will enable the prediction of the transcriptional state of CVGs from epigenomic data, which is important for the study of parasite adaptation to the conditions of the host in natural malaria infections.
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Richie TL, Church LWP, Murshedkar T, Billingsley PF, James ER, Chen MC, Abebe Y, KC N, Chakravarty S, Dolberg D, Healy SA, Diawara H, Sissoko MS, Sagara I, Cook DM, Epstein JE, Mordmüller B, Kapulu M, Kreidenweiss A, Franke-Fayard B, Agnandji ST, López Mikue MSA, McCall MBB, Steinhardt L, Oneko M, Olotu A, Vaughan AM, Kublin JG, Murphy SC, Jongo S, Tanner M, Sirima SB, Laurens MB, Daubenberger C, Silva JC, Lyke KE, Janse CJ, Roestenberg M, Sauerwein RW, Abdulla S, Dicko A, Kappe SHI, Lee Sim BK, Duffy PE, Kremsner PG, Hoffman SL. Sporozoite immunization: innovative translational science to support the fight against malaria. Expert Rev Vaccines 2023; 22:964-1007. [PMID: 37571809 PMCID: PMC10949369 DOI: 10.1080/14760584.2023.2245890] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 08/04/2023] [Indexed: 08/13/2023]
Abstract
INTRODUCTION Malaria, a devastating febrile illness caused by protozoan parasites, sickened 247,000,000 people in 2021 and killed 619,000, mostly children and pregnant women in sub-Saharan Africa. A highly effective vaccine is urgently needed, especially for Plasmodium falciparum (Pf), the deadliest human malaria parasite. AREAS COVERED Sporozoites (SPZ), the parasite stage transmitted by Anopheles mosquitoes to humans, are the only vaccine immunogen achieving >90% efficacy against Pf infection. This review describes >30 clinical trials of PfSPZ vaccines in the U.S.A., Europe, Africa, and Asia, based on first-hand knowledge of the trials and PubMed searches of 'sporozoites,' 'malaria,' and 'vaccines.' EXPERT OPINION First generation (radiation-attenuated) PfSPZ vaccines are safe, well tolerated, 80-100% efficacious against homologous controlled human malaria infection (CHMI) and provide 18-19 months protection without boosting in Africa. Second generation chemo-attenuated PfSPZ are more potent, 100% efficacious against stringent heterologous (variant strain) CHMI, but require a co-administered drug, raising safety concerns. Third generation, late liver stage-arresting, replication competent (LARC), genetically-attenuated PfSPZ are expected to be both safe and highly efficacious. Overall, PfSPZ vaccines meet safety, tolerability, and efficacy requirements for protecting pregnant women and travelers exposed to Pf in Africa, with licensure for these populations possible within 5 years. Protecting children and mass vaccination programs to block transmission and eliminate malaria are long-term objectives.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Sara A. Healy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Halimatou Diawara
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Mahamadou S. Sissoko
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Issaka Sagara
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - David M. Cook
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Judith E. Epstein
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Benjamin Mordmüller
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Melissa Kapulu
- Biosciences Department, Kenya Medical Research Institute KEMRI-Wellcome Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Andrea Kreidenweiss
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | | | - Selidji T. Agnandji
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | | | - Matthew B. B. McCall
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Laura Steinhardt
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Martina Oneko
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya
| | - Ally Olotu
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Ashley M. Vaughan
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - James G. Kublin
- Department of Global Health, University of Washington, Seattle, WA, USA
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Sean C. Murphy
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
- Center for Emerging and Re-emerging Infectious Diseases and Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Said Jongo
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Marcel Tanner
- Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Matthew B. Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Claudia Daubenberger
- Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Joana C. Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kirsten E. Lyke
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Chris J. Janse
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
| | - Robert W. Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Salim Abdulla
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Alassane Dicko
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Stefan H. I. Kappe
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | | | - Patrick E. Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Peter G. Kremsner
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
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Cryopreservation of Plasmodium Sporozoites. Pathogens 2022; 11:pathogens11121487. [PMID: 36558821 PMCID: PMC9784981 DOI: 10.3390/pathogens11121487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/28/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Malaria is a deadly disease caused by the parasite, Plasmodium, and impacts the lives of millions of people around the world. Following inoculation into mammalian hosts by infected mosquitoes, the sporozoite stage of Plasmodium undergoes obligate development in the liver before infecting erythrocytes and causing clinical malaria. The most promising vaccine candidates for malaria rely on the use of attenuated live sporozoites to induce protective immune responses. The scope of widespread testing or clinical use of such vaccines is limited by the absence of efficient, reliable, or transparent strategies for the long-term preservation of live sporozoites. Here we outline a method to cryopreserve the sporozoites of various human and murine Plasmodium species. We found that the structural integrity, viability, and in vivo or in vitro infectiousness were conserved in the recovered cryopreserved sporozoites. Cryopreservation using our approach also retained the transgenic properties of sporozoites and immunization with cryopreserved radiation attenuated sporozoites (RAS) elicited strong immune responses. Our work offers a reliable protocol for the long-term storage and recovery of human and murine Plasmodium sporozoites and lays the groundwork for the widespread use of live sporozoites for research and clinical applications.
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KC N, Church LWP, Riyahi P, Chakravarty S, Seder RA, Epstein JE, Lyke KE, Mordmüller B, Kremsner PG, Sissoko MS, Healy S, Duffy PE, Jongo SA, Nchama VUNN, Abdulla S, Mpina M, Sirima SB, Laurens MB, Steinhardt LC, Oneko M, Li M, Murshedkar T, Billingsley PF, Sim BKL, Richie TL, Hoffman SL. Increased levels of anti-PfCSP antibodies in post-pubertal females versus males immunized with PfSPZ Vaccine does not translate into increased protective efficacy. Front Immunol 2022; 13:1006716. [PMID: 36389797 PMCID: PMC9641621 DOI: 10.3389/fimmu.2022.1006716] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/30/2022] [Indexed: 11/25/2022] Open
Abstract
Background While prior research has shown differences in the risk of malaria infection and sickness between males and females, little is known about sex differences in vaccine-induced immunity to malaria. Identifying such differences could elucidate important aspects of malaria biology and facilitate development of improved approaches to malaria vaccination. Methods Using a standardized enzyme-linked immunosorbent assay, IgG antibodies to the major surface protein on Plasmodium falciparum (Pf) sporozoites (SPZ), the Pf circumsporozoite protein (PfCSP), were measured before and two weeks after administration of a PfSPZ-based malaria vaccine (PfSPZ Vaccine) to 5-month to 61-year-olds in 11 clinical trials in Germany, the US and five countries in Africa, to determine if there were differences in vaccine elicited antibody response between males and females and if these differences were associated with differential protection against naturally transmitted Pf malaria (Africa) or controlled human malaria infection (Germany, the US and Africa). Results Females ≥ 11 years of age made significantly higher levels of antibodies to PfCSP than did males in most trials, while there was no indication of such differences in infants or children. Although adult females had higher levels of antibodies, there was no evidence of improved protection compared to males. In 2 of the 7 trials with sufficient data, protected males had significantly higher levels of antibodies than unprotected males, and in 3 other trials protected females had higher levels of antibodies than did unprotected females. Conclusion Immunization with PfSPZ Vaccine induced higher levels of antibodies in post-pubertal females but showed equivalent protection in males and females. We conclude that the increased antibody levels in post-pubertal females did not contribute substantially to improved protection. We hypothesize that while antibodies to PfCSP (and PfSPZ) may potentially contribute directly to protection, they primarily correlate with other, potentially protective immune mechanisms, such as antibody dependent and antibody independent cellular responses in the liver.
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Affiliation(s)
- Natasha KC
- Sanaria Inc., Rockville, MD, United States
| | | | | | | | - Robert A. Seder
- Vaccine Research Center, National Institute of Heath, Bethesda, MD, United States
| | - Judith E. Epstein
- Naval Medical Research Center (NMRC), Silver Spring, MD, United States
| | - Kirsten E. Lyke
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Benjamin Mordmüller
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, Tübingen, Germany
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Peter G. Kremsner
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, Tübingen, Germany
- Centre de Recherches Medicales de Lambaréné, Lambaréné, Gabon
| | - Mahamadou S. Sissoko
- Malaria Research and Training Center (MRTC), Mali National Institute of Allergy and Infectious Diseases International Centers for Excellence in Research, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Sara Healy
- Laboratory of Malaria Immunology and Parasitology, National Institutes of Allergy and Infectious Diseases, National Institutes of Health (LMIV/NIAID/NIH), Rockville, MD, United States
| | - Patrick E. Duffy
- Laboratory of Malaria Immunology and Parasitology, National Institutes of Allergy and Infectious Diseases, National Institutes of Health (LMIV/NIAID/NIH), Rockville, MD, United States
| | - Said A. Jongo
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | | | - Salim Abdulla
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Maxmillian Mpina
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
- Swiss Tropical Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sodiomon B. Sirima
- Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Matthew B. Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Laura C. Steinhardt
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Martina Oneko
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya
| | - MingLin Li
- Sanaria Inc., Rockville, MD, United States
| | | | | | | | | | - Stephen L. Hoffman
- Sanaria Inc., Rockville, MD, United States
- *Correspondence: Stephen L. Hoffman,
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Choy RKM, Bourgeois AL, Ockenhouse CF, Walker RI, Sheets RL, Flores J. Controlled Human Infection Models To Accelerate Vaccine Development. Clin Microbiol Rev 2022; 35:e0000821. [PMID: 35862754 PMCID: PMC9491212 DOI: 10.1128/cmr.00008-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The timelines for developing vaccines against infectious diseases are lengthy, and often vaccines that reach the stage of large phase 3 field trials fail to provide the desired level of protective efficacy. The application of controlled human challenge models of infection and disease at the appropriate stages of development could accelerate development of candidate vaccines and, in fact, has done so successfully in some limited cases. Human challenge models could potentially be used to gather critical information on pathogenesis, inform strain selection for vaccines, explore cross-protective immunity, identify immune correlates of protection and mechanisms of protection induced by infection or evoked by candidate vaccines, guide decisions on appropriate trial endpoints, and evaluate vaccine efficacy. We prepared this report to motivate fellow scientists to exploit the potential capacity of controlled human challenge experiments to advance vaccine development. In this review, we considered available challenge models for 17 infectious diseases in the context of the public health importance of each disease, the diversity and pathogenesis of the causative organisms, the vaccine candidates under development, and each model's capacity to evaluate them and identify correlates of protective immunity. Our broad assessment indicated that human challenge models have not yet reached their full potential to support the development of vaccines against infectious diseases. On the basis of our review, however, we believe that describing an ideal challenge model is possible, as is further developing existing and future challenge models.
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Affiliation(s)
- Robert K. M. Choy
- PATH, Center for Vaccine Innovation and Access, Seattle, Washington, USA
| | - A. Louis Bourgeois
- PATH, Center for Vaccine Innovation and Access, Seattle, Washington, USA
| | | | - Richard I. Walker
- PATH, Center for Vaccine Innovation and Access, Seattle, Washington, USA
| | | | - Jorge Flores
- PATH, Center for Vaccine Innovation and Access, Seattle, Washington, USA
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Nunes-Cabaço H, Moita D, Prudêncio M. Five decades of clinical assessment of whole-sporozoite malaria vaccines. Front Immunol 2022; 13:977472. [PMID: 36159849 PMCID: PMC9493004 DOI: 10.3389/fimmu.2022.977472] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
In 1967, pioneering work by Ruth Nussenzweig demonstrated for the first time that irradiated sporozoites of the rodent malaria parasite Plasmodium berghei protected mice against a challenge with infectious parasites of the same species. This remarkable finding opened up entirely new prospects of effective vaccination against malaria using attenuated sporozoites as immunization agents. The potential for whole-sporozoite-based immunization in humans was established in a clinical study in 1973, when a volunteer exposed to X-irradiated P. falciparum sporozoites was found to be protected against malaria following challenge with a homologous strain of this parasite. Nearly five decades later, much has been achieved in the field of whole-sporozoite malaria vaccination, and multiple reports on the clinical evaluation of such candidates have emerged. However, this process has known different paces before and after the turn of the century. While only a few clinical studies were published in the 1970’s, 1980’s and 1990’s, remarkable progress was made in the 2000’s and beyond. This article reviews the history of the clinical assessment of whole-sporozoite malaria vaccines over the last forty-nine years, highlighting the impressive achievements made over the last few years, and discussing some of the challenges ahead.
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Chakravarty S, Shears MJ, James ER, Rai U, Kc N, Conteh S, Lambert LE, Duffy PE, Murphy SC, Hoffman SL. Efficient infection of non-human primates with purified, cryopreserved Plasmodium knowlesi sporozoites. Malar J 2022; 21:247. [PMID: 36030292 PMCID: PMC9418655 DOI: 10.1186/s12936-022-04261-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 07/17/2022] [Indexed: 11/29/2022] Open
Abstract
Background Plasmodium falciparum (Pf) sporozoite (SPZ) vaccines are the only candidate malaria vaccines that induce > 90% vaccine efficacy (VE) against controlled human malaria infection and the only malaria vaccines to have achieved reproducible VE against malaria in adults in Africa. The goal is to increase the impact and reduce the cost of PfSPZ vaccines by optimizing vaccine potency and manufacturing, which will benefit from identification of immunological responses contributing to protection in humans. Currently, there is no authentic animal challenge model for assessing P. falciparum malaria VE. Alternatively, Plasmodium knowlesi (Pk), which infects humans and non-human primates (NHPs) in nature, can be used to experimentally infect rhesus macaques (Macaca mulatta) to assess VE. Methods Sanaria has, therefore, produced purified, vialed, cryopreserved PkSPZ and conducted challenge studies in several naïve NHP cohorts. In the first cohort, groups of three rhesus macaques each received doses of 5 × 102, 2.5 × 103, 1.25 × 104 and 2.5 × 104 PkSPZ administered by direct venous inoculation. The infectivity of 1.5 × 103 PkSPZ cryopreserved with an altered method and of 1.5 × 103 PkSPZ cryopreserved for four years was tested in a second and third cohort of rhesus NHPs. The lastly, three pig-tailed macaques (Macaca nemestrina), a natural P. knowlesi host, were challenged with 2.5 × 103 PkSPZ cryopreserved six years earlier. Results In the first cohort, all 12 animals developed P. knowlesi parasitaemia by thick blood smear, and the time to positivity (prepatent period) followed a non-linear 4-parameter logistic sigmoidal model with a median of 11, 10, 8, and 7 days, respectively (r2 = 1). PkSPZ cryopreserved using a modified rapid-scalable method infected rhesus with a pre-patent period of 10 days, as did PkSPZ cryopreserved four years prior to infection, similar to the control group. Cryopreserved PkSPZ infected pig-tailed macaques with median time to positivity by thin smear, of 11 days. Conclusion This study establishes the capacity to consistently infect NHPs with purified, vialed, cryopreserved PkSPZ, providing a foundation for future studies to probe protective immunological mechanisms elicited by PfSPZ vaccines that cannot be established in humans. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04261-z.
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Affiliation(s)
- Sumana Chakravarty
- Sanaria, Inc, 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Melanie J Shears
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA.,Washington National Primate Research Center, University of Washington, Seattle, WA, USA
| | - Eric R James
- Sanaria, Inc, 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Urvashi Rai
- Sanaria, Inc, 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Natasha Kc
- Sanaria, Inc, 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Solomon Conteh
- Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, Bethesda, USA
| | - Lynn E Lambert
- Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, Bethesda, USA
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, Bethesda, USA
| | - Sean C Murphy
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA.,Washington National Primate Research Center, University of Washington, Seattle, WA, USA.,Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Stephen L Hoffman
- Sanaria, Inc, 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA.
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10
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A PfSPZ vaccine immunization regimen equally protective against homologous and heterologous controlled human malaria infection. NPJ Vaccines 2022; 7:100. [PMID: 35999221 PMCID: PMC9396563 DOI: 10.1038/s41541-022-00510-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 06/24/2022] [Indexed: 11/08/2022] Open
Abstract
Immunization with radiation-attenuated Plasmodium falciparum (Pf) sporozoites (SPZ) in PfSPZ Vaccine, has provided better vaccine efficacy (VE) against controlled human malaria infection (CHMI) with the same parasites as in the vaccine (homologous) than with genetically distant parasites (heterologous). We sought to identify an immunization regimen that provided similar VE against CHMI with homologous and heterologous Pf for at least 9 weeks in malaria-naïve adults. Such a regimen was identified in part 1 (optimization), an open label study, and confirmed in part 2 (verification), a randomized, double-blind, placebo-controlled study in which VE was assessed by cross-over repeat CHMI with homologous (PfNF54) and heterologous (Pf7G8) PfSPZ at 3 and 9–10 weeks. VE was calculated using Bayesian generalized linear regression. In part 1, vaccination with 9 × 105 PfSPZ on days 1, 8, and 29 protected 5/5 (100%) subjects against homologous CHMI at 3 weeks after the last immunization. In part 2, the same 3-dose regimen protected 5/6 subjects (83%) against heterologous CHMI at both 3 and 9–10 weeks after the last immunization. Overall VE was 78% (95% predictive interval: 57–92%), and against heterologous and homologous was 79% (95% PI: 54–95%) and 77% (95% PI: 50–95%) respectively. PfSPZ Vaccine was safe and well tolerated. A 4-week, 3-dose regimen of PfSPZ Vaccine provided similar VE for 9–10 weeks against homologous and heterologous CHMI. The trial is registered with ClinicalTrials.gov, NCT02704533.
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11
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Nouatin O, Ibáñez J, Fendel R, Ngoa UA, Lorenz FR, Dejon-Agobé JC, Edoa JR, Flügge J, Brückner S, Esen M, Theisen M, Hoffman SL, Moutairou K, Luty AJF, Lell B, Kremsner PG, Adegnika AA, Mordmüller B. Cellular and antibody response in GMZ2-vaccinated Gabonese volunteers in a controlled human malaria infection trial. Malar J 2022; 21:191. [PMID: 35715803 PMCID: PMC9204906 DOI: 10.1186/s12936-022-04169-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 04/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Antibody and cellular memory responses following vaccination are important measures of immunogenicity. These immune markers were quantified in the framework of a vaccine trial investigating the malaria vaccine candidate GMZ2. METHODS Fifty Gabonese adults were vaccinated with two formulations (aluminum Alhydrogel and CAF01) of GMZ2 or a control vaccine (Verorab). Vaccine efficacy was assessed using controlled human malaria infection (CHMI) by direct venous inoculation of 3200 live Plasmodium falciparum sporozoites (PfSPZ Challenge). GMZ2-stimulated T and specific B-cell responses were estimated by flow cytometry before and after vaccination. Additionally, the antibody response against 212 P. falciparum antigens was estimated before CHMI by protein microarray. RESULTS Frequencies of pro- and anti-inflammatory CD4+ T cells stimulated with the vaccine antigen GMZ2 as well as B cell profiles did not change after vaccination. IL-10-producing CD4+ T cells and CD20+ IgG+ B cells were increased post-vaccination regardless of the intervention, thus could not be specifically attributed to any malaria vaccine regimen. In contrast, GMZ2-specific antibody response increased after the vaccination, but was not correlated to protection. Antibody responses to several P. falciparum blood and liver stage antigens (MSP1, MSP4, MSP8, PfEMP1, STARP) as well as the breadth of the malaria-specific antibody response were significantly higher in protected study participants. CONCLUSIONS In lifelong malaria exposed adults, the main marker of protection against CHMI is a broad antibody pattern recognizing multiple stages of the plasmodial life cycle. Despite vaccination with GMZ2 using a novel formulation, expansion of the GMZ2-stimulated T cells or the GMZ2-specific B cell response was limited, and the vaccine response could not be identified as a marker of protection against malaria. Trial registration PACTR; PACTR201503001038304; Registered 17 February 2015; https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=1038.
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Affiliation(s)
- Odilon Nouatin
- Centre de Recherches Médicales de Lambaréné, BP : 242, Lambaréné, Gabon. .,Institute of Tropical Medicine, University Tübingen, Wilhelmstr. 27, 72074, Tübingen, Germany. .,German Centre for Infection Research (DZIF), Partner Site, Tübingen, Germany. .,Département de Biochimie Et de Biologie Cellulaire, Faculté des Sciences et Techniques, Université d'Abomey-Calavi, Cotonou, Bénin.
| | - Javier Ibáñez
- Institute of Tropical Medicine, University Tübingen, Wilhelmstr. 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site, Tübingen, Germany
| | - Rolf Fendel
- Centre de Recherches Médicales de Lambaréné, BP : 242, Lambaréné, Gabon. .,Institute of Tropical Medicine, University Tübingen, Wilhelmstr. 27, 72074, Tübingen, Germany. .,German Centre for Infection Research (DZIF), Partner Site, Tübingen, Germany.
| | - Ulysse A Ngoa
- Centre de Recherches Médicales de Lambaréné, BP : 242, Lambaréné, Gabon
| | - Freia-Raphaella Lorenz
- Institute of Tropical Medicine, University Tübingen, Wilhelmstr. 27, 72074, Tübingen, Germany
| | - Jean-Claude Dejon-Agobé
- Centre de Recherches Médicales de Lambaréné, BP : 242, Lambaréné, Gabon.,Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Jean Ronald Edoa
- Centre de Recherches Médicales de Lambaréné, BP : 242, Lambaréné, Gabon.,Institute of Tropical Medicine, University Tübingen, Wilhelmstr. 27, 72074, Tübingen, Germany
| | - Judith Flügge
- Institute of Tropical Medicine, University Tübingen, Wilhelmstr. 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site, Tübingen, Germany
| | - Sina Brückner
- Institute of Tropical Medicine, University Tübingen, Wilhelmstr. 27, 72074, Tübingen, Germany
| | - Meral Esen
- Centre de Recherches Médicales de Lambaréné, BP : 242, Lambaréné, Gabon.,Institute of Tropical Medicine, University Tübingen, Wilhelmstr. 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site, Tübingen, Germany.,Cluster of Excellence: EXC 2124: Controlling Microbes to Fight Infection, Tübingen, Germany
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark
| | | | - Kabirou Moutairou
- Département de Biochimie Et de Biologie Cellulaire, Faculté des Sciences et Techniques, Université d'Abomey-Calavi, Cotonou, Bénin
| | - Adrian J F Luty
- Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et a l'Enfance, Calavi, Bénin.,MERIT, Université de Paris, Paris, IRD, France
| | - Bertrand Lell
- Centre de Recherches Médicales de Lambaréné, BP : 242, Lambaréné, Gabon.,Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Peter G Kremsner
- Centre de Recherches Médicales de Lambaréné, BP : 242, Lambaréné, Gabon.,Institute of Tropical Medicine, University Tübingen, Wilhelmstr. 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site, Tübingen, Germany
| | - Ayola A Adegnika
- Centre de Recherches Médicales de Lambaréné, BP : 242, Lambaréné, Gabon.,Institute of Tropical Medicine, University Tübingen, Wilhelmstr. 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site, Tübingen, Germany.,Department of Parasitology, Leiden University Medical Centre (LUMC), 2333 ZA, Leiden, The Netherlands.,Fondation pour la Recherche Scientifique, 72 BP45, Cotonou, Bénin
| | - Benjamin Mordmüller
- Centre de Recherches Médicales de Lambaréné, BP : 242, Lambaréné, Gabon.,Institute of Tropical Medicine, University Tübingen, Wilhelmstr. 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site, Tübingen, Germany.,Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
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12
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James ER, Matheny S, Overby J, Sim BKL, Eappen AG, Li T, Li ML, Richie TL, Chakravarty S, Gunasekera A, Murshedkar T, Billingsley PF, Hoffman SL. A First for Human Vaccinology: GMP Compliant Radiation Attenuation of Plasmodium falciparum Sporozoites for Production of a Vaccine Against Malaria. Front Immunol 2022; 13:851028. [PMID: 35242146 PMCID: PMC8886114 DOI: 10.3389/fimmu.2022.851028] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 01/25/2022] [Indexed: 11/23/2022] Open
Abstract
Ionizing radiation (UV, X-ray and ɣ) administered at an appropriate dose to pathogenic organisms can prevent replication while preserving metabolic activity. We have established the GMP process for attenuation by ionizing radiation of the Plasmodium falciparum (Pf) sporozoites (SPZ) in Sanaria® PfSPZ Vaccine, a protective vaccine against malaria. Mosquitoes raised and infected aseptically with Pf were transferred into infected mosquito transport containers (IMTC) and ɣ-irradiated using a 60Co source. PfSPZ were then extracted, purified, vialed, and cryopreserved. To establish the appropriate radiation conditions, the irradiation field inside the IMTCs was mapped using radiochromic film and alanine transfer dosimeters. Dosimeters were irradiated for times calculated to provide 120-170 Gy at the minimum dose location inside the IMTC and regression analysis was used to determine the time required to achieve a lower 95% confidence interval for 150 Gy. A formula incorporating the half-life of 60Co was then used to construct tables of irradiation times for each calendar day. From the mapping studies, formulae were derived to estimate the minimum and maximum doses of irradiation received inside the IMTC from a reference dosimeter mounted on the outside wall. For PfSPZ Vaccine manufacture a dose of 150 Gy was targeted for each irradiation event, a dose known to completely attenuate PfSPZ. The reference dosimeters were processed by the National Institute of Standards and Technology. There have been 587 irradiation events to produce PfSPZ Vaccine during 13 years which generated multiple lots released for pre-clinical studies and clinical trials. The estimated doses at the minimum dose location (mean 154.3 ± 1.77 Gy; range 150.0-159.3 Gy), and maximum dose location (mean 166.3 ± 3.65 Gy, range 155.7 to 175.3 Gy), in IMTCs were normally distributed. Overall dose uniformity was 1.078 ± 0.012. There was no siginifcant change in measured dose over 13 years. As of January 2022, 21 clinical trials of PfSPZ Vaccine have been conducted, with 1,740 volunteers aged 5 months to 61 years receiving 5,648 doses of PfSPZ Vaccine totalling >5.3 billion PfSPZ administered. There have been no breakthrough infections, confirming the consistency and robustness of the radiation attenuation process.
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Affiliation(s)
| | | | | | | | | | - Tao Li
- Sanaria Inc., Rockville, MD, United States
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13
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Kapulu MC, Kimani D, Njuguna P, Hamaluba M, Otieno E, Kimathi R, Tuju J, Sim BKL, Abdi AI, Abebe Y, Bejon P, Billingsley PF, Bull PC, de Laurent Z, Hoffman SL, James ER, Kariuki S, Kinyanjui S, Kivisi C, Makale J, Marsh K, Mohammed KS, Mosobo M, Musembi J, Musyoki J, Muthui M, Mwacharo J, Mwai K, Ngoi JM, Ngoto O, Nkumama I, Ndungu F, Odera D, Ogutu B, Olewe F, Omuoyo D, Ong’echa J, Osier F, Richie TL, Shangala J, Wambua J, Williams TN. Controlled human malaria infection (CHMI) outcomes in Kenyan adults is associated with prior history of malaria exposure and anti-schizont antibody response. BMC Infect Dis 2022; 22:86. [PMID: 35073864 PMCID: PMC8785382 DOI: 10.1186/s12879-022-07044-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 01/11/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Individuals living in endemic areas acquire immunity to malaria following repeated parasite exposure. We sought to assess the controlled human malaria infection (CHMI) model as a means of studying naturally acquired immunity in Kenyan adults with varying malaria exposure.
Methods
We analysed data from 142 Kenyan adults from three locations representing distinct areas of malaria endemicity (Ahero, Kilifi North and Kilifi South) enrolled in a CHMI study with Plasmodium falciparum sporozoites NF54 strain (Sanaria® PfSPZ Challenge). To identify the in vivo outcomes that most closely reflected naturally acquired immunity, parameters based on qPCR measurements were compared with anti-schizont antibody levels and residence as proxy markers of naturally acquired immunity.
Results
Time to endpoint correlated more closely with anti-schizont antibodies and location of residence than other parasite parameters such as growth rate or mean parasite density. Compared to observational field-based studies in children where 0.8% of the variability in malaria outcome was observed to be explained by anti-schizont antibodies, in the CHMI model the dichotomized anti-schizont antibodies explained 17% of the variability.
Conclusions
The CHMI model is highly effective in studying markers of naturally acquired immunity to malaria.
Trial registration Clinicaltrials.gov number NCT02739763. Registered 15 April 2016
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14
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Shibeshi W, Bagchus W, Yalkinoglu Ö, Tappert A, Engidawork E, Oeuvray C. Reproducibility of malaria sporozoite challenge model in humans for evaluating efficacy of vaccines and drugs: a systematic review. BMC Infect Dis 2021; 21:1274. [PMID: 34930178 PMCID: PMC8686662 DOI: 10.1186/s12879-021-06953-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/06/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The development of novel malaria vaccines and antimalarial drugs is limited partly by emerging challenges to conduct field trials in malaria endemic areas, including unknown effects of existing immunity and a reported fall in malaria incidence. As a result, Controlled Human Malaria Infection (CHMI) has become an important approach for accelerated development of malarial vaccines and drugs. We conducted a systematic review of the literature to establish aggregate evidence on the reproducibility of a malaria sporozoite challenge model. METHODS A systematic review of research articles published between 1990 and 2018 on efficacy testing of malaria vaccines and drugs using sporozoite challenge and sporozoite infectivity studies was conducted using Pubmed, Scopus, Embase and Cochrane Library, ClinicalTrials.gov and Trialtrove. The inclusion criteria were randomized and non-randomized, controlled or open-label trials using P. falciparum or P. vivax sporozoite challenges. The data were extracted from articles using standardized data extraction forms and descriptive analysis was performed for evidence synthesis. The endpoints considered were infectivity, prepatent period, parasitemia and safety of sporozoite challenge. RESULTS Seventy CHMI trials conducted with a total of 2329 adult healthy volunteers were used for analysis. CHMI was induced by bites of mosquitoes infected with P. falciparum or P. vivax in 52 trials and by direct venous inoculation of P. falciparum sporozoites (PfSPZ challenge) in 18 trials. Inoculation with P. falciparum-infected mosquitoes produced 100% infectivity in 40 studies and the mean/median prepatent period assessed by thick blood smear (TBS) microscopy was ≤ 12 days in 24 studies. On the other hand, out of 12 infectivity studies conducted using PfSPZ challenge, 100% infection rate was reproduced in 9 studies with a mean or median prepatent period of 11 to 15.3 days as assessed by TBS and 6.8 to 12.6 days by PCR. The safety profile of P. falciparum and P.vivax CHMI was characterized by consistent features of malaria infection. CONCLUSION There is ample evidence on consistency of P. falciparum CHMI models in terms of infectivity and safety endpoints, which supports applicability of CHMI in vaccine and drug development. PfSPZ challenge appears more feasible for African trials based on current evidence of safety and efficacy.
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Affiliation(s)
- Workineh Shibeshi
- Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
- Global Health Institute of Merck, Ares Trading S.A., A subsidiary of Merck KGaA, Darmstadt, Germany.
| | - Wilhelmina Bagchus
- Translational Medicine, Merck Serono S.A., An Affiliate of Merck KGaA, Darmstadt, Germany
| | - Özkan Yalkinoglu
- Translational Medicine, Merck Healthcare KGaA, Darmstadt, Germany
| | - Aliona Tappert
- Global Patient Safety, Merck Healthcare KGaA, Darmstadt, Germany
| | - Ephrem Engidawork
- Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Claude Oeuvray
- Global Health Institute of Merck, Ares Trading S.A., A subsidiary of Merck KGaA, Darmstadt, Germany
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15
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M'baya B, Mfune T, Samon A, Hwandih T, Münster M. Evaluation of the Sysmex XN-31 automated analyser for blood donor malaria screening at Malawi Blood Transfusion Services. Vox Sang 2021; 117:346-353. [PMID: 34558082 PMCID: PMC9290921 DOI: 10.1111/vox.13208] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 12/26/2022]
Abstract
Background and Objectives Balancing blood supply safety and sufficiency is challenging in malaria‐endemic countries where the risk of transfusion‐transmitted malaria (TTM) is ever‐present. In support of reducing this risk, our study aimed at evaluating the performance of the Sysmex XN‐31 analyser in blood donor malaria screening, as compared with current practice in Malawi. Materials and Methods This prospective observational study was conducted on remnant venous donor blood samples collected at Malawi Blood Transfusion Service donation sites countrywide for routine blood‐borne pathogen screening. XN‐31 results were compared with routine thick smear malaria microscopy, using expert microscopy (phase 1 and 2) plus qualitative malaria polymerase chain reaction (PCR) (phase 2) to adjudicate discrepancies. Results XN‐31 detected malaria in 614 (11.6%) of 5281 study samples compared with 341 (6.5%) for routine microscopy. Of the 273 discrepant samples, 60 smears (phase 1) could not be retrieved for expert microscopic review. Expert microscopy confirmed the XN‐31 positivity in 78.8% (149/189) and 91.7% (22/24) of discrepant samples in phase 1 (n = 4416) and phase 2 (n = 975), respectively, with two cases requiring PCR testing, confirming one each as positive and negative, giving sensitivities of 100% and 75% and specificities of 99.9% and 100%, respectively, for XN‐31 and routine microscopy. Conclusion The automated Sysmex XN‐31 analyser's high sensitivity and specificity, ability to detect all Plasmodium species and high throughput with rapid turnaround‐time, overcomes many of the limitations of currently available diagnostic tests, making it well‐suited for malaria screening of donated blood in malaria‐endemic countries in support of TTM risk reduction.
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Affiliation(s)
| | - Thom Mfune
- Malawi Blood Transfusion Service, Blantyre, Malawi
| | - Aubrey Samon
- Malawi Blood Transfusion Service, Blantyre, Malawi
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16
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Kapulu MC, Njuguna P, Hamaluba M, Kimani D, Ngoi JM, Musembi J, Ngoto O, Otieno E, Billingsley PF. Safety and PCR monitoring in 161 semi-immune Kenyan adults following controlled human malaria infection. JCI Insight 2021; 6:e146443. [PMID: 34264864 PMCID: PMC8492329 DOI: 10.1172/jci.insight.146443] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 07/14/2021] [Indexed: 11/26/2022] Open
Abstract
BACKGROUNDNaturally acquired immunity to malaria is incompletely understood. We used controlled human malaria infection (CHMI) to study the impact of past exposure on malaria in Kenyan adults in relation to infection with a non-Kenyan parasite strain.METHODSWe administered 3.2 × 103 aseptic, purified, cryopreserved Plasmodium falciparum sporozoites (Sanaria PfSPZ Challenge, NF54 West African strain) by direct venous inoculation and undertook clinical monitoring and serial quantitative PCR (qPCR) of the 18S ribosomal RNA gene. The study endpoint was met when parasitemia reached 500 or more parasites per μL blood, clinically important symptoms were seen, or at 21 days after inoculation. All volunteers received antimalarial drug treatment upon meeting the endpoint.RESULTSOne hundred and sixty-one volunteers underwent CHMI between August 4, 2016, and February 14, 2018. CHMI was well tolerated, with no severe or serious adverse events. Nineteen volunteers (11.8%) were excluded from the analysis based on detection of antimalarial drugs above the minimal inhibitory concentration or parasites genotyped as non-NF54. Of the 142 volunteers who were eligible for analysis, 26 (18.3%) had febrile symptoms and were treated; 30 (21.1%) reached 500 or more parasites per μL and were treated; 53 (37.3%) had parasitemia without meeting thresholds for treatment; and 33 (23.2%) remained qPCR negative.CONCLUSIONWe found that past exposure to malaria, as evidenced by location of residence, in some Kenyan adults can completely suppress in vivo growth of a parasite strain originating from outside Kenya.TRIAL REGISTRATIONClinicalTrials.gov NCT02739763.FUNDINGWellcome Trust.
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Affiliation(s)
- Melissa C. Kapulu
- Centre for Geographic Medicine Research, Coast, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Patricia Njuguna
- Centre for Geographic Medicine Research, Coast, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Mainga Hamaluba
- Centre for Geographic Medicine Research, Coast, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Domtila Kimani
- Centre for Geographic Medicine Research, Coast, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Joyce M. Ngoi
- Centre for Geographic Medicine Research, Coast, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Janet Musembi
- Centre for Geographic Medicine Research, Coast, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Omar Ngoto
- Centre for Geographic Medicine Research, Coast, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Edward Otieno
- Centre for Geographic Medicine Research, Coast, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
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17
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Expression Patterns of Plasmodium falciparum Clonally Variant Genes at the Onset of a Blood Infection in Malaria-Naive Humans. mBio 2021; 12:e0163621. [PMID: 34340541 PMCID: PMC8406225 DOI: 10.1128/mbio.01636-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clonally variant genes (CVGs) play fundamental roles in the adaptation of Plasmodium falciparum to fluctuating conditions of the human host. However, their expression patterns under the natural conditions of the blood circulation have been characterized in detail for only a few specific gene families. Here, we provide a detailed characterization of the complete P. falciparum transcriptome across the full intraerythrocytic development cycle (IDC) at the onset of a blood infection in malaria-naive human volunteers. We found that the vast majority of transcriptional differences between parasites obtained from the volunteers and the parental parasite line maintained in culture occurred in CVGs. In particular, we observed a major increase in the transcript levels of most genes of the pfmc-2tm and gbp families and of specific genes of other families, such as phist, hyp10, rif, or stevor, in addition to previously reported changes in var and clag3 gene expression. Increased transcript levels of individual pfmc-2tm, rif, and stevor genes involved activation in small subsets of parasites. Large transcriptional differences correlated with changes in the distribution of heterochromatin, confirming their epigenetic nature. Furthermore, the similar expression of several CVGs between parasites collected at different time points along the blood infection suggests that the epigenetic memory for multiple CVG families is lost during transmission stages, resulting in a reset of their transcriptional state. Finally, the CVG expression patterns observed in a volunteer likely infected by a single sporozoite suggest that new epigenetic patterns are established during liver stages.
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18
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Billingsley PF, George KI, Eappen AG, Harrell RA, Alford R, Li T, Chakravarty S, Sim BKL, Hoffman SL, O'Brochta DA. Transient knockdown of Anopheles stephensi LRIM1 using RNAi increases Plasmodium falciparum sporozoite salivary gland infections. Malar J 2021; 20:284. [PMID: 34174879 PMCID: PMC8235909 DOI: 10.1186/s12936-021-03818-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 06/15/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodium falciparum (Pf) sporozoites (PfSPZ) can be administered as a highly protective vaccine conferring the highest protection seen to date. Sanaria® PfSPZ vaccines are produced using aseptically reared Anopheles stephensi mosquitoes. The bionomics of sporogonic development of P. falciparum in A. stephensi to fully mature salivary gland PfSPZ is thought to be modulated by several components of the mosquito innate immune system. In order to increase salivary gland PfSPZ infections in A. stephensi and thereby increase vaccine production efficiency, a gene knock down approach was used to investigate the activity of the immune deficiency (IMD) signaling pathway downstream effector leucine-rich repeat immune molecule 1 (LRIM1), an antagonist to Plasmodium development. METHODS Expression of LRIM1 in A. stephensi was reduced following injection of double stranded (ds) RNA into mosquitoes. By combining the Gal4/UAS bipartite system with in vivo expression of short hairpin (sh) RNA coding for LRIM1 reduced expression of LRIM1 was targeted in the midgut, fat body, and salivary glands. RT-qPCR was used to demonstrate fold-changes in gene expression in three transgenic crosses and the effects on P. falciparum infections determined in mosquitoes showing the greatest reduction in LRIM1 expression. RESULTS LRIM1 expression could be reduced, but not completely silenced, by expression of LRIM1 dsRNA. Infections of P. falciparum oocysts and PfSPZ were consistently and significantly higher in transgenic mosquitoes than wild type controls, with increases in PfSPZ ranging from 2.5- to tenfold. CONCLUSIONS Plasmodium falciparum infections in A. stephensi can be increased following reduced expression of LRIM1. These data provide the springboard for more precise knockout of LRIM1 for the eventual incorporation of immune-compromised A. stephensi into manufacturing of Sanaria's PfSPZ products.
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Affiliation(s)
- Peter F Billingsley
- Sanaria Inc, Suite A209, 9800 Medical Center Drive, Rockville, MD, 20850, USA.
| | - Kasim I George
- Institute for Bioscience and Biotechnology Research and Department of Entomology, University of Maryland, Gudelsky Drive, Rockville, MD, 20850, USA
- Qiagen Inc, 19300 Germantown Road, Germantown, MD, 20874, USA
| | - Abraham G Eappen
- Sanaria Inc, Suite A209, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Robert A Harrell
- Institute for Bioscience and Biotechnology Research and Department of Entomology, University of Maryland, Gudelsky Drive, Rockville, MD, 20850, USA
- Insect Transformation Facility, Institute for Bioscience and Biotechnology Research, University of Maryland, 9600 Gudelsky Drive, Rockville, MD, 20850, USA
| | - Robert Alford
- Institute for Bioscience and Biotechnology Research and Department of Entomology, University of Maryland, Gudelsky Drive, Rockville, MD, 20850, USA
- Insect Transformation Facility, Institute for Bioscience and Biotechnology Research, University of Maryland, 9600 Gudelsky Drive, Rockville, MD, 20850, USA
| | - Tao Li
- Sanaria Inc, Suite A209, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Sumana Chakravarty
- Sanaria Inc, Suite A209, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - B Kim Lee Sim
- Sanaria Inc, Suite A209, 9800 Medical Center Drive, Rockville, MD, 20850, USA
- Protein Potential, Suite A209, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Stephen L Hoffman
- Sanaria Inc, Suite A209, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - David A O'Brochta
- Institute for Bioscience and Biotechnology Research and Department of Entomology, University of Maryland, Gudelsky Drive, Rockville, MD, 20850, USA
- Foundation for the National Institutes of Health, 11400 Rockville Pike, Suite 600, North Bethesda, MD, 20852, USA
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19
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Murphy SC, Deye GA, Sim BKL, Galbiati S, Kennedy JK, Cohen KW, Chakravarty S, KC N, Abebe Y, James ER, Kublin JG, Hoffman SL, Richie TL, Jackson LA. PfSPZ-CVac efficacy against malaria increases from 0% to 75% when administered in the absence of erythrocyte stage parasitemia: A randomized, placebo-controlled trial with controlled human malaria infection. PLoS Pathog 2021; 17:e1009594. [PMID: 34048504 PMCID: PMC8191919 DOI: 10.1371/journal.ppat.1009594] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 06/10/2021] [Accepted: 04/29/2021] [Indexed: 11/18/2022] Open
Abstract
PfSPZ-CVac combines 'PfSPZ Challenge', which consists of infectious Plasmodium falciparum sporozoites (PfSPZ), with concurrent antimalarial chemoprophylaxis. In a previously-published PfSPZ-CVac study, three doses of 5.12x104 PfSPZ-CVac given 28 days apart had 100% vaccine efficacy (VE) against controlled human malaria infection (CHMI) 10 weeks after the last immunization, while the same dose given as three injections five days apart had 63% VE. Here, we conducted a dose escalation trial of similarly condensed schedules. Of the groups proceeding to CHMI, the first study group received three direct venous inoculations (DVIs) of a dose of 5.12x104 PfSPZ-CVac seven days apart and the next full dose group received three DVIs of a higher dose of 1.024x105 PfSPZ-CVac five days apart. CHMI (3.2x103 PfSPZ Challenge) was performed by DVI 10 weeks after the last vaccination. In both CHMI groups, transient parasitemia occurred starting seven days after each vaccination. For the seven-day interval group, the second and third vaccinations were therefore administered coincident with parasitemia from the prior vaccination. Parasitemia was associated with systemic symptoms which were severe in 25% of subjects. VE in the seven-day group was 0% (7/7 infected) and in the higher-dose, five-day group was 75% (2/8 infected). Thus, the same dose of PfSPZ-CVac previously associated with 63% VE when given on a five-day schedule in the prior study had zero VE here when given on a seven-day schedule, while a double dose given on a five-day schedule here achieved 75% VE. The relative contributions of the five-day schedule and/or the higher dose to improved VE warrant further investigation. It is notable that administration of PfSPZ-CVac on a schedule where vaccine administration coincided with blood-stage parasitemia was associated with an absence of sterile protective immunity. Clinical trials registration: NCT02773979.
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Affiliation(s)
- Sean C. Murphy
- Seattle Malaria Clinical Trials Center, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
- Center for Emerging and Re-emerging Infectious Diseases, Seattle, Washington, United States of America
| | - Gregory A. Deye
- Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - B. Kim Lee Sim
- Sanaria Inc., Rockville, Maryland, United States of America
| | - Shirley Galbiati
- The Emmes Company, Rockville, Maryland, United States of America
| | | | - Kristen W. Cohen
- Seattle Malaria Clinical Trials Center, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | | | - Natasha KC
- Sanaria Inc., Rockville, Maryland, United States of America
| | - Yonas Abebe
- Sanaria Inc., Rockville, Maryland, United States of America
| | - Eric R. James
- Sanaria Inc., Rockville, Maryland, United States of America
| | - James G. Kublin
- Seattle Malaria Clinical Trials Center, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | | | | | - Lisa A. Jackson
- Kaiser Permanente Washington Health Research Institute, Seattle, Washington, United States of America
- * E-mail:
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20
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Systems analysis and controlled malaria infection in Europeans and Africans elucidate naturally acquired immunity. Nat Immunol 2021; 22:654-665. [PMID: 33888898 DOI: 10.1038/s41590-021-00911-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 03/02/2021] [Indexed: 01/31/2023]
Abstract
Controlled human infections provide opportunities to study the interaction between the immune system and malaria parasites, which is essential for vaccine development. Here, we compared immune signatures of malaria-naive Europeans and of Africans with lifelong malaria exposure using mass cytometry, RNA sequencing and data integration, before and 5 and 11 days after venous inoculation with Plasmodium falciparum sporozoites. We observed differences in immune cell populations, antigen-specific responses and gene expression profiles between Europeans and Africans and among Africans with differing degrees of immunity. Before inoculation, an activated/differentiated state of both innate and adaptive cells, including elevated CD161+CD4+ T cells and interferon-γ production, predicted Africans capable of controlling parasitemia. After inoculation, the rapidity of the transcriptional response and clusters of CD4+ T cells, plasmacytoid dendritic cells and innate T cells were among the features distinguishing Africans capable of controlling parasitemia from susceptible individuals. These findings can guide the development of a vaccine effective in malaria-endemic regions.
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21
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Manheim D, Wiȩcek W, Schmit V, Morrison J. Exploring Risks of Human Challenge Trials For COVID-19. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2021; 41:710-720. [PMID: 33942351 PMCID: PMC8207107 DOI: 10.1111/risa.13726] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Human challenge trials (HCTs) are a potential method to accelerate development of vaccines and therapeutics. However, HCTs for COVID-19 pose ethical and practical challenges, in part due to the unclear and developing risks. In this article , we introduce an interactive model for exploring some risks of a severe acute respiratory syndrome coronavirus-2 (SARS-COV-2) dosing study, a prerequisite for any COVID-19 challenge trials. The risk estimates we use are based on a Bayesian evidence synthesis model which can incorporate new data on infection fatality risks (IFRs) to patients, and infer rates of hospitalization. The model estimates individual risk, which we then extrapolate to overall mortality and hospitalization risk in a dosing study. We provide a web tool to explore risk under different study designs. Based on the Bayesian model, IFR for someone between 20 and 30 years of age is 15.1 in 100,000, with a 95% uncertainty interval from 11.8 to 19.2, while risk of hospitalization is 130 per 100,000 (100-160). However, risk will be reduced in an HCT via screening for comorbidities, selecting lower-risk population, and providing treatment. Accounting for this with stronger assumptions, we project the fatality risk to be as low as 2.5 per 100,000 (1.6-3.9) and the hospitalization risk to be 22.0 per 100,000 (14.0-33.7). We therefore find a 50-person dosing trial has a 99.74% (99.8-99.9%) chance of no fatalities, and a 98.9% (98.3-99.3%) probability of no cases requiring hospitalization.
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Affiliation(s)
- David Manheim
- 1DaySooner, Wilmington, DE, USA
- Health and Risk Communication Research Center, University of Haifa, School of Public Health, Haifa, Israel
| | - Witold Wiȩcek
- 1DaySooner, Wilmington, DE, USA
- WAW Statistical Consulting Ltd., UK
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22
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Jongo SA, Church LWP, Mtoro AT, Schindler T, Chakravarty S, Ruben AJ, Swanson PA, Kassim KR, Mpina M, Tumbo AM, Milando FA, Qassim M, Juma OA, Bakari BM, Simon B, James ER, Abebe Y, Kc N, Saverino E, Fink M, Cosi G, Gondwe L, Studer F, Styers D, Seder RA, Schindler T, Billingsley PF, Daubenberger C, Sim BKL, Tanner M, Richie TL, Abdulla S, Hoffman SL. Increase of Dose Associated With Decrease in Protection Against Controlled Human Malaria Infection by PfSPZ Vaccine in Tanzanian Adults. Clin Infect Dis 2021; 71:2849-2857. [PMID: 31782768 DOI: 10.1093/cid/ciz1152] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 11/28/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND A vaccine would be an ideal tool for reducing malaria's impact. PfSPZ Vaccine (radiation attenuated, aseptic, purified, cryopreserved Plasmodium falciparum [Pf] sporozoites [SPZ]) has been well tolerated and safe in >1526 malaria-naive and experienced 6-month to 65-year-olds in the United States, Europe, and Africa. When vaccine efficacy (VE) of 5 doses of 2.7 × 105 PfSPZ of PfSPZ Vaccine was assessed in adults against controlled human malaria infection (CHMI) in the United States and Tanzania and intense field transmission of heterogeneous Pf in Mali, Tanzanians had the lowest VE (20%). METHODS To increase VE in Tanzania, we increased PfSPZ/dose (9 × 105 or 1.8 × 106) and decreased numbers of doses to 3 at 8-week intervals in a double blind, placebo-controlled trial. RESULTS All 22 CHMIs in controls resulted in parasitemia by quantitative polymerase chain reaction. For the 9 × 105 PfSPZ group, VE was 100% (5/5) at 3 or 11 weeks (P < .000l, Barnard test, 2-tailed). For 1.8 × 106 PfSPZ, VE was 33% (2/6) at 7.5 weeks (P = .028). VE of dosage groups (100% vs 33%) was significantly different (P = .022). Volunteers underwent repeat CHMI at 37-40 weeks after last dose. 6/6 and 5/6 volunteers developed parasitemia, but time to first parasitemia was significantly longer than controls in the 9 × 105 PfSPZ group (10.89 vs 7.80 days) (P = .039), indicating a significant reduction in parasites in the liver. Antibody and T-cell responses were higher in the 1.8 × 106 PfSPZ group. CONCLUSIONS In Tanzania, increasing the dose from 2.7 × 105 to 9 × 105 PfSPZ increased VE from 20% to 100%, but increasing to 1.8 × 106 PfSPZ significantly reduced VE. CLINICAL TRIALS REGISTRATION NCT02613520.
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Affiliation(s)
- Said A Jongo
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | | | - Ali T Mtoro
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Tobias Schindler
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
| | | | | | - Phillip A Swanson
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Kamaka R Kassim
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Maximillian Mpina
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
| | - Anneth-Mwasi Tumbo
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
| | - Florence A Milando
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Munira Qassim
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Omar A Juma
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Bakari M Bakari
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Beatus Simon
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | | | | | | | | | - Martina Fink
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
| | - Glenda Cosi
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
| | - Linda Gondwe
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
| | - Fabian Studer
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
| | | | - Robert A Seder
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Tobias Schindler
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
| | | | - Claudia Daubenberger
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
| | - B Kim Lee Sim
- Sanaria Inc., Rockville, Maryland, USA.,Protein Potential LLC, Rockville, Maryland, USA
| | - Marcel Tanner
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
| | | | - Salim Abdulla
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
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23
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Chughlay MF, El Gaaloul M, Donini C, Campo B, Berghmans PJ, Lucardie A, Marx MW, Cherkaoui-Rbati MH, Langdon G, Angulo-Barturen I, Viera S, Rosanas-Urgell A, Van Geertruyden JP, Chalon S. Chemoprotective Antimalarial Activity of P218 against Plasmodium falciparum: A Randomized, Placebo-Controlled Volunteer Infection Study. Am J Trop Med Hyg 2021; 104:1348-1358. [PMID: 33556040 PMCID: PMC8045640 DOI: 10.4269/ajtmh.20-1165] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 12/02/2020] [Indexed: 11/07/2022] Open
Abstract
P218 is a highly selective dihydrofolate reductase inhibitor with potent in vitro activity against pyrimethamine-resistant Plasmodium falciparum. This single-center, randomized, double-blind, placebo-controlled phase Ib study evaluated P218 safety, pharmacokinetics, and chemoprotective efficacy in a P. falciparum sporozoite (PfSPZ) volunteer infection study (VIS). Consecutive dose safety and tolerability were evaluated (cohort 1), with participants receiving two oral doses of P218 1,000 mg 48 hours apart (n = 6), or placebo (n = 2). P218 chemoprotective efficacy was assessed (cohorts 2 and 3) with direct venous inoculation of 3,200 aseptic, cryopreserved PfSPZ (NF54 strain) followed 2 hours later with two P218 doses of 1,000 mg (cohort 2, n = 9) or 100 mg (cohort 3, n = 9) administered 48 hours apart, or placebo (n = 6). Parasitemia was assessed from day 7 using quantitative PCR targeting the var gene acidic terminal sequence (varATS qPCR). By day 28, all participants in cohort 2 (P218 1,000 mg) and 8/9 in cohort 3 (P218 100 mg) were sterilely protected post-PfSPZ VIS, confirming P218 P. falciparum chemoprotective activity. With placebo, all six participants became parasitemic (geometric mean time to positive parasitemia 10.6 days [90% CI: 9.9–11.4]). P218 pharmacokinetics were similar in participants with or without induced infection. Adverse events of any cause occurred in 45.8% (11/24) of participants who received P218 and 50.0% (4/8) following placebo; all were mild/moderate in severity, transient, and self-limiting. There were no clinically relevant changes in laboratory parameters, vital signs, or electrocardiograms. P218 displayed excellent chemoprotective efficacy against P. falciparum with favorable safety and tolerability.
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Affiliation(s)
| | | | | | - Brice Campo
- 1Medicines for Malaria Venture, Geneva, Switzerland
| | | | | | | | | | | | | | - Sara Viera
- 5GlaxoSmithKline, Tres Cantos, Madrid, Spain
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24
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Jongo SA, Urbano V, Church LWP, Olotu A, Manock SR, Schindler T, Mtoro A, Kc N, Hamad A, Nyakarungu E, Mpina M, Deal A, Bijeri JR, Ondo Mangue ME, Ntutumu Pasialo BE, Nguema GN, Owono SN, Rivas MR, Chemba M, Kassim KR, James ER, Stabler TC, Abebe Y, Saverino E, Sax J, Hosch S, Tumbo AM, Gondwe L, Segura JL, Falla CC, Phiri WP, Hergott DEB, García GA, Schwabe C, Maas CD, Murshedkar T, Billingsley PF, Tanner M, Ayekaba MO, Sim BKL, Daubenberger C, Richie TL, Abdulla S, Hoffman SL. Immunogenicity and Protective Efficacy of Radiation-Attenuated and Chemo-Attenuated PfSPZ Vaccines in Equatoguinean Adults. Am J Trop Med Hyg 2021; 104:283-293. [PMID: 33205741 PMCID: PMC7790068 DOI: 10.4269/ajtmh.20-0435] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Plasmodium falciparum sporozoite (PfSPZ) Vaccine (radiation-attenuated, aseptic, purified, cryopreserved PfSPZ) and PfSPZ-CVac (infectious, aseptic, purified, cryopreserved PfSPZ administered to subjects taking weekly chloroquine chemoprophylaxis) have shown vaccine efficacies (VEs) of 100% against homologous controlled human malaria infection (CHMI) in nonimmune adults. Plasmodium falciparum sporozoite-CVac has never been assessed against CHMI in African vaccinees. We assessed the safety, immunogenicity, and VE against homologous CHMI of three doses of 2.7 × 106 PfSPZ of PfSPZ Vaccine at 8-week intervals and three doses of 1.0 × 105 PfSPZ of PfSPZ-CVac at 4-week intervals with each arm randomized, double-blind, placebo-controlled, and conducted in parallel. There were no differences in solicited adverse events between vaccinees and normal saline controls, or between PfSPZ Vaccine and PfSPZ-CVac recipients during the 6 days after administration of investigational product. However, from days 7–13, PfSPZ-CVac recipients had significantly more AEs, probably because of Pf parasitemia. Antibody responses were 2.9 times higher in PfSPZ Vaccine recipients than PfSPZ-CVac recipients at time of CHMI. Vaccine efficacy at a median of 14 weeks after last PfSPZ-CVac dose was 55% (8 of 13, P = 0.051) and at a median of 15 weeks after last PfSPZ Vaccine dose was 27% (5 of 15, P = 0.32). The higher VE in PfSPZ-CVac recipients of 55% with a 27-fold lower dose was likely a result of later stage parasite maturation in the liver, leading to induction of cellular immunity against a greater quantity and broader array of antigens.
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Affiliation(s)
- Said A Jongo
- 1Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Vicente Urbano
- 2Ministry of Health and Social Welfare, Government of Equatorial Guinea, Bioko Norte, Equatorial Guinea
| | | | - Ally Olotu
- 1Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | | | | | - Ali Mtoro
- 1Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Natasha Kc
- 3Sanaria Inc., Rockville, Maryland.,5Protein Potential LLC, Rockville, Maryland
| | - Ali Hamad
- 1Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Elizabeth Nyakarungu
- 1Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | | | - Anna Deal
- 4Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - José Raso Bijeri
- 2Ministry of Health and Social Welfare, Government of Equatorial Guinea, Bioko Norte, Equatorial Guinea
| | - Martin Eka Ondo Mangue
- 2Ministry of Health and Social Welfare, Government of Equatorial Guinea, Bioko Norte, Equatorial Guinea
| | | | - Genaro Nsue Nguema
- 2Ministry of Health and Social Welfare, Government of Equatorial Guinea, Bioko Norte, Equatorial Guinea
| | - Salomon Nguema Owono
- 2Ministry of Health and Social Welfare, Government of Equatorial Guinea, Bioko Norte, Equatorial Guinea
| | - Matilde Riloha Rivas
- 2Ministry of Health and Social Welfare, Government of Equatorial Guinea, Bioko Norte, Equatorial Guinea
| | - Mwajuma Chemba
- 1Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Kamaka R Kassim
- 1Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | | | | | | | | | - Julian Sax
- 4Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Salome Hosch
- 4Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | - Linda Gondwe
- 4Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - J Luis Segura
- 6Medical Care Development International, Silver Spring, Maryland
| | | | | | | | | | | | - Carl D Maas
- 7Marathon EG Production, Ltd., Bioko Norte, Equatorial Guinea
| | | | | | - Marcel Tanner
- 4Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Mitoha Ondo'o Ayekaba
- 2Ministry of Health and Social Welfare, Government of Equatorial Guinea, Bioko Norte, Equatorial Guinea
| | - B Kim Lee Sim
- 3Sanaria Inc., Rockville, Maryland.,5Protein Potential LLC, Rockville, Maryland
| | | | | | - Salim Abdulla
- 1Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
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25
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Billingsley PF, Maas CD, Olotu A, Schwabe C, García GA, Rivas MR, Hergott DEB, Daubenberger C, Saverino E, Chaouch A, Embon O, Chemba M, Nyakarungu E, Hamad A, Cortes C, Schindler T, Mpina M, Mtoro A, Sim BKL, Richie TL, McGhee K, Tanner M, Obiang Lima GM, Abdulla S, Hoffman SL, Ayekaba MO. The Equatoguinean Malaria Vaccine Initiative: From the Launching of a Clinical Research Platform to Malaria Elimination Planning in Central West Africa. Am J Trop Med Hyg 2020; 103:947-954. [PMID: 32458790 PMCID: PMC7470544 DOI: 10.4269/ajtmh.19-0966] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Fifteen years of investment in malaria control on Bioko Island, Equatorial Guinea (EG), dramatically reduced malaria-associated morbidity and mortality, but the impact has plateaued. To progress toward elimination, EG is investing in the development of a malaria vaccine. We assessed the unique public–private partnership that has had such a significant impact on malaria on Bioko Island and now added a major effort on malaria vaccine development. As part of a $79M commitment, the EG government (75%) and three American energy companies (25%) have invested since 2012 greater than $55M in the Equatoguinean Malaria Vaccine Initiative (EGMVI) to support clinical development of Sanaria® PfSPZ vaccines (Sanaria Inc., Rockville, MD). In turn, the vaccine development program is building human capital and physical capacity. The EGMVI established regulatory and ethical oversight to ensure compliance with the International Conference on Harmonization and Good Clinical Practices for the first importation of investigational product, ethical approval, and conduct of a clinical trial in Equatoguinean history. The EGMVI has completed three vaccine trials in EG, two vaccine trials in Tanzania, and a malaria incidence study, and initiated preparations for a 2,100-volunteer clinical trial. Personnel are training for advanced degrees abroad and have been trained in Good Clinical Practices and protocol-specific methods. A new facility has established the foundation for a national research institute. Biomedical research and development within this visionary, ambitious public–private partnership is fostering major improvements in EG. The EGMVI plans to use a PfSPZ Vaccine alongside standard malaria control interventions to eliminate Pf malaria from Bioko, becoming a potential model for elimination campaigns elsewhere.
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Affiliation(s)
| | - Carl D Maas
- Marathon Oil, Malabo Dos, Bioko Norte, Equatorial Guinea
| | - Ally Olotu
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya.,Ifakara Health Institute, Bagamoyo, Tanzania
| | | | | | - Matilde Riloha Rivas
- Ministry of Health and Social Welfare, Government of Equatorial Guinea, Malabo, Equatorial Guinea
| | | | - Claudia Daubenberger
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | - Adel Chaouch
- Marathon Oil, Malabo Dos, Bioko Norte, Equatorial Guinea
| | - Oscar Embon
- La Paz Hospital Medical Center, Sipopo, Equatorial Guinea
| | | | | | - Ali Hamad
- Ifakara Health Institute, Bagamoyo, Tanzania
| | - Carlos Cortes
- Medical Care Development International, Silver Spring, Maryland
| | - Tobias Schindler
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Maximillian Mpina
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,Ifakara Health Institute, Bagamoyo, Tanzania
| | - Ali Mtoro
- Ifakara Health Institute, Bagamoyo, Tanzania
| | | | | | - Ken McGhee
- Noble Energy, Malabo Dos, Equatorial Guinea
| | - Marcel Tanner
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | | | | | - Mitoha Ondo'o Ayekaba
- Ministry of Health and Social Welfare, Government of Equatorial Guinea, Malabo, Equatorial Guinea.,Marathon Oil, Malabo Dos, Bioko Norte, Equatorial Guinea
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26
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Achan J, Reuling IJ, Yap XZ, Dabira E, Ahmad A, Cox M, Nwakanma D, Tetteh K, Wu L, Bastiaens GJH, Abebe Y, Manoj A, Kaur H, Miura K, Long C, Billingsley PF, Sim BKL, Hoffman SL, Drakeley C, Bousema T, D’Alessandro U. Serologic Markers of Previous Malaria Exposure and Functional Antibodies Inhibiting Parasite Growth Are Associated With Parasite Kinetics Following a Plasmodium falciparum Controlled Human Infection. Clin Infect Dis 2020; 70:2544-2552. [PMID: 31402382 PMCID: PMC7286377 DOI: 10.1093/cid/ciz740] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/01/2019] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND We assessed the impact of exposure to Plasmodium falciparum on parasite kinetics, clinical symptoms, and functional immunity after controlled human malaria infection (CHMI) in 2 cohorts with different levels of previous malarial exposure. METHODS Nine adult males with high (sero-high) and 10 with low (sero-low) previous exposure received 3200 P. falciparum sporozoites (PfSPZ) of PfSPZ Challenge by direct venous inoculation and were followed for 35 days for parasitemia by thick blood smear (TBS) and quantitative polymerase chain reaction. Endpoints were time to parasitemia, adverse events, and immune responses. RESULTS Ten of 10 (100%) volunteers in the sero-low and 7 of 9 (77.8%) in the sero-high group developed parasitemia detected by TBS in the first 28 days (P = .125). The median time to parasitemia was significantly shorter in the sero-low group than the sero-high group (9 days [interquartile range {IQR} 7.5-11.0] vs 11.0 days [IQR 7.5-18.0], respectively; log-rank test, P = .005). Antibody recognition of sporozoites was significantly higher in the sero-high (median, 17.93 [IQR 12.95-24] arbitrary units [AU]) than the sero-low volunteers (median, 10.54 [IQR, 8.36-12.12] AU) (P = .006). Growth inhibitory activity was significantly higher in the sero-high (median, 21.8% [IQR, 8.15%-29.65%]) than in the sero-low group (median, 8.3% [IQR, 5.6%-10.23%]) (P = .025). CONCLUSIONS CHMI was safe and well tolerated in this population. Individuals with serological evidence of higher malaria exposure were able to better control infection and had higher parasite growth inhibitory activity. CLINICAL TRIALS REGISTRATION NCT03496454.
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Affiliation(s)
- Jane Achan
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Isaie J Reuling
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Xi Zen Yap
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Edgard Dabira
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Abdullahi Ahmad
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Momodou Cox
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Davis Nwakanma
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Kevin Tetteh
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Lindsey Wu
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Guido J H Bastiaens
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | | | - Harparkash Kaur
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Carole Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | | | | | | | - Chris Drakeley
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Umberto D’Alessandro
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia
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27
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Nouatin O, Ateba Ngoa U, Ibáñez J, Dejon-Agobe JC, Mordmüller B, Edoa JR, Mougeni F, Brückner S, Bouyoukou Hounkpatin A, Esen M, Theisen M, Moutairou K, Hoffman SL, Issifou S, Luty AJF, Loembe MM, Agnandji ST, Lell B, Kremsner PG, Adegnika AA. Effect of immune regulatory pathways after immunization with GMZ2 malaria vaccine candidate in healthy lifelong malaria-exposed adults. Vaccine 2020; 38:4263-4272. [PMID: 32386747 PMCID: PMC7297038 DOI: 10.1016/j.vaccine.2020.04.046] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/08/2020] [Accepted: 04/20/2020] [Indexed: 01/01/2023]
Abstract
BACKGROUND Despite appreciable immunogenicity in malaria-naive populations, many candidate malaria vaccines are considerably less immunogenic in malaria-exposed populations. This could reflect induction of immune regulatory mechanisms involving Human Leukocyte Antigen G (HLA-G), regulatory T (Treg), and regulatory B (Breg) cells. Here, we addressed the question whether there is correlation between these immune regulatory pathways and both plasmablast frequencies and vaccine-specific IgG concentrations. METHODS Fifty Gabonese adults with lifelong exposure to Plasmodium spp were randomized to receive three doses of either 30 µg or 100 µg GMZ2-CAF01, or 100 µg GMZ2-alum, or control vaccine (rabies vaccine) at 4-week intervals. Only plasma and peripheral blood mononuclear cells isolated from blood samples collected before (D0) and 28 days after the third vaccination (D84) of 35 participants were used to measure sHLA-G levels and anti-GMZ2 IgG concentrations, and to quantify Treg, Breg and plasmablast cells. Vaccine efficacy was assessed using controlled human malaria infection (CHMI) by direct venous inoculation of Plasmodium falciparum sporozoites (PfSPZ Challenge). RESULTS The sHLA-G concentration increased from D0 to D84 in all GMZ2 vaccinated participants and in the control group, whereas Treg frequencies increased only in those receiving 30 µg or 100 µg GMZ2-CAF01. The sHLA-G level on D84 was associated with a decrease of the anti-GMZ2 IgG concentration, whereas Treg frequencies on D0 or on D84, and Breg frequency on D84 were associated with lower plasmablast frequencies. Importantly, having a D84:D0 ratio of sHLA-G above the median was associated with an increased risk of P. falciparum infection after sporozoites injection. CONCLUSION Regulatory immune responses are induced following immunization. Stronger sHLA-G and Treg immune responses may suppress vaccine induced immune responses, and the magnitude of the sHLA-G response increased the risk of Plasmodium falciparum infection after CHMI. These findings could have implications for the design and testing of malaria vaccine candidates in semi-immune individuals.
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Affiliation(s)
- Odilon Nouatin
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon; Institut für Tropenmedizin, Universität Tubingen, Wilhelmstraβe 27, D-72074 Tübingen, Germany; Germany; German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany; Département de Biochimie et de Biologie Cellulaire, Faculté des Sciences et Techniques, Université d'Abomey-Calavi, Cotonou, Benin.
| | - Ulysse Ateba Ngoa
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon.
| | - Javier Ibáñez
- Institut für Tropenmedizin, Universität Tubingen, Wilhelmstraβe 27, D-72074 Tübingen, Germany
| | - Jean Claude Dejon-Agobe
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon; Institut für Tropenmedizin, Universität Tubingen, Wilhelmstraβe 27, D-72074 Tübingen, Germany
| | - Benjamin Mordmüller
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon; Institut für Tropenmedizin, Universität Tubingen, Wilhelmstraβe 27, D-72074 Tübingen, Germany; Germany; German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany.
| | - Jean Ronald Edoa
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon; Institut für Tropenmedizin, Universität Tubingen, Wilhelmstraβe 27, D-72074 Tübingen, Germany.
| | - Fabrice Mougeni
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon
| | - Sina Brückner
- Institut für Tropenmedizin, Universität Tubingen, Wilhelmstraβe 27, D-72074 Tübingen, Germany.
| | - Aurore Bouyoukou Hounkpatin
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon; Institut für Tropenmedizin, Universität Tubingen, Wilhelmstraβe 27, D-72074 Tübingen, Germany
| | - Meral Esen
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon; Institut für Tropenmedizin, Universität Tubingen, Wilhelmstraβe 27, D-72074 Tübingen, Germany; Germany; German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany.
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark and Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark.
| | - Kabirou Moutairou
- Département de Biochimie et de Biologie Cellulaire, Faculté des Sciences et Techniques, Université d'Abomey-Calavi, Cotonou, Benin.
| | | | - Saadou Issifou
- Fondation pour la Recherche Scientifique, 72 BP45 Cotonou, Benin.
| | - Adrian J F Luty
- Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance, Faculté des Sciences de la Santé, Université d'Abomey-Calavi, Cotonou, MERIT UMR D216, Benin; Université de Paris, MERIT, IRD, Paris, France.
| | - Marguerite M Loembe
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon; Institut für Tropenmedizin, Universität Tubingen, Wilhelmstraβe 27, D-72074 Tübingen, Germany; Germany; German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany.
| | - Selidji Todagbé Agnandji
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon; Institut für Tropenmedizin, Universität Tubingen, Wilhelmstraβe 27, D-72074 Tübingen, Germany; Germany; German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany.
| | - Bertrand Lell
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon; Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria.
| | - Peter G Kremsner
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon; Institut für Tropenmedizin, Universität Tubingen, Wilhelmstraβe 27, D-72074 Tübingen, Germany; Germany; German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany.
| | - Ayôla Akim Adegnika
- Centre de Recherches Médicales de Lambaréné, BP: 242 Lambaréné, Gabon; Institut für Tropenmedizin, Universität Tubingen, Wilhelmstraβe 27, D-72074 Tübingen, Germany; Germany; German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany; Leiden University Medical Centre (LUMC), 2333 ZA Leiden, the Netherlands.
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28
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Schmaler M, Orlova-Fink N, Rutishauser T, Abdulla S, Daubenberger C. Human unconventional T cells in Plasmodium falciparum infection. Semin Immunopathol 2020; 42:265-277. [PMID: 32076813 PMCID: PMC7223888 DOI: 10.1007/s00281-020-00791-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 02/07/2020] [Indexed: 12/22/2022]
Abstract
Malaria is an old scourge of humankind and has a large negative impact on the economic development of affected communities. Recent success in malaria control and reduction of mortality seems to have stalled emphasizing that our current intervention tools need to be complemented by malaria vaccines. Different populations of unconventional T cells such as mucosal-associated invariant T (MAIT) cells, invariant natural killer T (iNKT) cells and γδ T cells are gaining attention in the field of malaria immunology. Significant advances in our basic understanding of unconventional T cell biology in rodent malaria models have been made, however, their roles in humans during malaria are less clear. Unconventional T cells are abundant in skin, gut and liver tissues, and long-lasting expansions and functional alterations were observed upon malaria infection in malaria naïve and malaria pre-exposed volunteers. Here, we review the current understanding of involvement of unconventional T cells in anti-Plasmodium falciparum immunity and highlight potential future research avenues.
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Affiliation(s)
- Mathias Schmaler
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - Nina Orlova-Fink
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - Tobias Rutishauser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - Salim Abdulla
- Ifakara Health Institute, Bagamoyo Clinical Trial Unit, Bagamoyo, Tanzania
| | - Claudia Daubenberger
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland.
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29
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Bekeredjian-Ding I, Van Molle W, Baay M, Neels P. Human challenge trial workshop: Focus on quality requirements for challenge agents, Langen, Germany, October 22, 2019. Biologicals 2020; 66:53-61. [PMID: 32389512 DOI: 10.1016/j.biologicals.2020.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 04/29/2020] [Indexed: 01/01/2023] Open
Abstract
Controlled human infection models can be helpful to study pathogenesis and immune responses as a basis for the development of vaccines. In controlled human infection models, human challenge agents are used to infect healthy volunteers, therefore, ethical considerations include that the exposure studies need to be safe and results should be meaningful, e.g. contribute to a better cure. Both in the US and in Europe, the level of Good Manufacturing Practice required is related to the phase of the study ('sliding scale Good Manufacturing Practice'), and, hence, is much more open to speedy drug development than anticipated. Recommendations included: the development of guidelines for human challenge agents; a focus on strain selection, in particular with regard to strain infectivity, stability and purity; the use of whole genome sequencing; a reference repository of challenge agents, the need for early exchange with regulators to ensure acceptability of strain selection and manufacturing for later drug development; sharing of models and challenge agents.
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Affiliation(s)
- Isabelle Bekeredjian-Ding
- Paul-Ehrlich-Institut (PEI), Langen, Germany; Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany.
| | | | - Marc Baay
- P95 Epidemiology & Pharmacovigilance, Leuven, Belgium.
| | - Pieter Neels
- International Alliance for Biological Standardization (IABS), Belgium.
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30
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Chughlay MF, Akakpo S, Odedra A, Csermak-Renner K, Djeriou E, Winnips C, Leboulleux D, Gaur AH, Shanks GD, McCarthy J, Chalon S. Liver Enzyme Elevations in Plasmodium falciparum Volunteer Infection Studies: Findings and Recommendations. Am J Trop Med Hyg 2020; 103:378-393. [PMID: 32314694 PMCID: PMC7356411 DOI: 10.4269/ajtmh.19-0846] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Malaria volunteer infection studies (VISs) accelerate new drug and vaccine development. In the induced blood-stage malaria (IBSM) model, volunteers are inoculated with erythrocytes infected with Plasmodium falciparum. Observations of elevated liver enzymes in the IBSM model with new chemical entities (NCEs) promoted an analysis of available data. Data were reviewed from eight IBSM studies of seven different NCEs, plus two studies with the registered antimalarial piperaquine conducted between June 2013 and January 2017 at QIMR Berghofer, Brisbane, Australia. Alanine aminotransferase (ALT) was elevated (> 2.5 times the upper limit of normal [×ULN]) in 20/114 (17.5%) participants. Of these, 8.9% (10/114) had moderate increases (> 2.5–5 × ULN), noted in seven studies of six different NCEs ± piperaquine or piperaquine alone, and 8.9% (10/114) had severe elevations (> 5 × ULN), occurring in six studies of six different NCEs ± piperaquine. Aspartate aminotransferase (AST) was elevated (> 2.5 × ULN) in 11.4% (13/114) of participants, across six of the 10 studies. Bilirubin was > 2 × ULN in one participant. Published data from other VIS models, using sporozoite inoculation by systemic administration or mosquito feeding, also showed moderate/severe liver enzyme elevations. In conclusion, liver enzyme elevations in IBSM studies are most likely multifactorial and could be caused by the model conditions, that is, malaria infection/parasite density and/or effective parasite clearance, or by participant-specific risk factors, acetaminophen administration, or direct hepatotoxicity of the test drug. We make recommendations that may mitigate the risk of liver enzyme elevations in future VISs and propose measures to assist their interpretation, should they occur.
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Affiliation(s)
| | | | - Anand Odedra
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | | | | | | | | | - Aditya H Gaur
- St. Jude Children's Research Hospital, Memphis, Tennessee
| | - G Dennis Shanks
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - James McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
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31
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Langenberg MCC, Dekkers OM, Roestenberg M. Are placebo controls necessary in controlled human infection trials for vaccines? THE LANCET. INFECTIOUS DISEASES 2020; 20:e69-e74. [PMID: 32142640 DOI: 10.1016/s1473-3099(20)30020-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 01/02/2020] [Accepted: 01/12/2020] [Indexed: 12/18/2022]
Abstract
Controlled human infection trials, whereby a small group of healthy participants is deliberately exposed to a pathogen under controlled circumstances, can provide preliminary data for vaccine efficacy and for the selection of the most promising candidate vaccines for field trials. Because of the potential harm to participants through the deliberate exposure to a pathogen, the use of smaller groups minimises the cumulative risk. As such, a control group that receives a placebo vaccine followed by controlled exposure to a pathogen should be scientifically well justified. As these types of trials are designed to generate consistent infection rates and thus comparable outcomes across populations and trial sites, data from past studies (historical data) could be used as a valid alternative to placebo groups. In this Personal View, we review this option and highlight the considerations for choosing historical data as a suitable control. For the widespread application of this method, responsibility for the centralisation and sharing of data from controlled human infection trials lies with the scientific community.
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Affiliation(s)
| | - Olaf M Dekkers
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, Netherlands
| | - Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands; Department of Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands.
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32
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Amelia F, Iyori M, Emran TB, Yamamoto DS, Genshi K, Otsuka H, Onoue Y, Yusuf Y, Islam A, Yoshida S. Down-selecting circumsporozoite protein-based malaria vaccine: A comparison of malaria sporozoite challenge model. Parasite Immunol 2020; 41:e12624. [PMID: 30883819 DOI: 10.1111/pim.12624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 02/28/2019] [Accepted: 03/08/2019] [Indexed: 12/18/2022]
Abstract
Plasmodium falciparum circumsporozoite protein (PfCSP) is the main target antigen in development of pre-erythrocytic malaria vaccines. To evaluate PfCSP vaccines in animal models, challenge by intravenous sporozoite injection is preferentially used. However, in clinical trials, vaccinated human volunteers are exposed to the bites of malaria-infected mosquitoes. In this study, we down-selected Escherichia coli-produced full-length PfCSP (PfCSP-F) and its three truncated PfCSPs based on their abilities to elicit immune response and protection in mice against two challenge models. We showed that immunization with three doses of PfCSP-F elicited high anti-PfCSP antibody titres and 100% protection against the bites of infected mosquitoes. Meanwhile, three-dose truncated PfCSP induced 60%-70% protection after immunization with each truncated PfCSP. Heterologous prime-boost immunization regimen with adenovirus-PfCSP-F and R32LR greatly induced complete protection against intravenous sporozoite injection. Our results suggest that Abs to both anti-repeat and anti-nonrepeat regions induced by PfCSP-F are required to confer complete protection against challenge by the bites of infected mosquitoes, whereas anti-repeat Abs play an important role in protection against intravenous sporozoite injection. Our findings provide a potential clinical application that PfCSP-F vaccine induces potent Abs capable of neutralizing sporozoites in the dermis inoculated by infected mosquitoes and subsequently sporozoites in the blood circulation.
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Affiliation(s)
- Fitri Amelia
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan.,Department of Chemistry, Universitas Negeri Padang, Padang, Indonesia
| | - Mitsuhiro Iyori
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Talha Bin Emran
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Daisuke S Yamamoto
- Division of Medical Zoology, Department of Infection and Immunity, Jichi Medical University, Shimotsuke, Japan
| | - Kento Genshi
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Hiromu Otsuka
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Yutaro Onoue
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Yenni Yusuf
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Ashekul Islam
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
| | - Shigeto Yoshida
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa, Japan
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33
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Jongo SA, Church LWP, Mtoro AT, Chakravarty S, Ruben AJ, Swanson PA, Kassim KR, Mpina M, Tumbo AM, Milando FA, Qassim M, Juma OA, Bakari BM, Simon B, James ER, Abebe Y, Kc N, Saverino E, Gondwe L, Studer F, Fink M, Cosi G, El-Khorazaty J, Styers D, Seder RA, Schindler T, Billingsley PF, Daubenberger C, Sim BKL, Tanner M, Richie TL, Abdulla S, Hoffman SL. Safety and Differential Antibody and T-Cell Responses to the Plasmodium falciparum Sporozoite Malaria Vaccine, PfSPZ Vaccine, by Age in Tanzanian Adults, Adolescents, Children, and Infants. Am J Trop Med Hyg 2020; 100:1433-1444. [PMID: 30994090 PMCID: PMC6553883 DOI: 10.4269/ajtmh.18-0835] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In 2016, there were more cases and deaths caused by malaria globally than in 2015. An effective vaccine would be an ideal additional tool for reducing malaria's impact. Sanaria® PfSPZ Vaccine, composed of radiation-attenuated, aseptic, purified, cryopreserved Plasmodium falciparum (Pf) sporozoites (SPZ) has been well tolerated and safe in malaria-naïve and experienced adults in the United States and Mali and protective against controlled human malaria infection with Pf in the United States and field transmission of Pf in Mali, but had not been assessed in younger age groups. We, therefore, evaluated PfSPZ Vaccine in 93 Tanzanians aged 45 years to 6 months in a randomized, double-blind, normal saline placebo-controlled trial. There were no significant differences in adverse events between vaccinees and controls or between dosage regimens. Because all age groups received three doses of 9.0 × 105 PfSPZ of PfSPZ Vaccine, immune responses were compared at this dosage. Median antibody responses against Pf circumsporozoite protein and PfSPZ were highest in infants and lowest in adults. T-cell responses were highest in 6-10-year olds after one dose and 1-5-year olds after three doses; infants had no significant positive T-cell responses. The safety data were used to support initiation of trials in > 300 infants in Kenya and Equatorial Guinea. Because PfSPZ Vaccine-induced protection is thought to be mediated by T cells, the T-cell data suggest PfSPZ Vaccine may be more protective in children than in adults, whereas infants may not be immunologically mature enough to respond to the PfSPZ Vaccine immunization regimen assessed.
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Affiliation(s)
- Said A Jongo
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | | | - Ali T Mtoro
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | | | | | - Phillip A Swanson
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Kamaka R Kassim
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Maximillian Mpina
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Anneth-Mwasi Tumbo
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Florence A Milando
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Munira Qassim
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Omar A Juma
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Bakari M Bakari
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | - Beatus Simon
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
| | | | | | | | | | - Linda Gondwe
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Fabian Studer
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Martina Fink
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Glenda Cosi
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | | | - Robert A Seder
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Tobias Schindler
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | - Claudia Daubenberger
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - B Kim Lee Sim
- Protein Potential LLC, Rockville, Maryland.,Sanaria, Inc., Rockville, Maryland
| | - Marcel Tanner
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | - Salim Abdulla
- Ifakara Health Institute, Bagamoyo Research and Training Centre, Bagamoyo, Tanzania
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Seilie AM, Chang M, Hanron AE, Billman ZP, Stone BC, Zhou K, Olsen TM, Daza G, Ortega J, Cruz KR, Smith N, Healy SA, Neal J, Wallis CK, Shelton L, Mankowski TV, Wong-Madden S, Mikolajczak SA, Vaughan AM, Kappe SHI, Fishbaugher M, Betz W, Kennedy M, Hume JCC, Talley AK, Hoffman SL, Chakravarty S, Sim BKL, Richie TL, Wald A, Plowe CV, Lyke KE, Adams M, Fahle GA, Cowan EP, Duffy PE, Kublin JG, Murphy SC. Beyond Blood Smears: Qualification of Plasmodium 18S rRNA as a Biomarker for Controlled Human Malaria Infections. Am J Trop Med Hyg 2020; 100:1466-1476. [PMID: 31017084 PMCID: PMC6553913 DOI: 10.4269/ajtmh.19-0094] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
18S rRNA is a biomarker that provides an alternative to thick blood smears in controlled human malaria infection (CHMI) trials. We reviewed data from CHMI trials at non-endemic sites that used blood smears and Plasmodium 18S rRNA/rDNA biomarker nucleic acid tests (NATs) for time to positivity. We validated a multiplex quantitative reverse transcription–polymerase chain reaction (qRT-PCR) for Plasmodium 18S rRNA, prospectively compared blood smears and qRT-PCR for three trials, and modeled treatment effects at different biomarker-defined parasite densities to assess the impact on infection detection, symptom reduction, and measured intervention efficacy. Literature review demonstrated accelerated NAT-based infection detection compared with blood smears (mean acceleration: 3.2–3.6 days). For prospectively tested trials, the validated Plasmodium 18S rRNA qRT-PCR positivity was earlier (7.6 days; 95% CI: 7.1–8.1 days) than blood smears (11.0 days; 95% CI: 10.3–11.8 days) and significantly preceded the onset of grade 2 malaria-related symptoms (12.2 days; 95% CI: 10.6–13.3 days). Discrepant analysis showed that the risk of a blood smear–positive, biomarker-negative result was negligible. Data modeling predicted that treatment triggered by specific biomarker-defined thresholds can differentiate complete, partial, and non-protective outcomes and eliminate many grade 2 and most grade 3 malaria-related symptoms post-CHMI. Plasmodium 18S rRNA is a sensitive and specific biomarker that can justifiably replace blood smears for infection detection in CHMI trials in non-endemic settings. This study led to biomarker qualification through the U.S. Food and Drug Administration for use in CHMI studies at non-endemic sites, which will facilitate biomarker use for the qualified context of use in drug and vaccine trials.
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Affiliation(s)
- Annette M Seilie
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Ming Chang
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Amelia E Hanron
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Zachary P Billman
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Brad C Stone
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Kevin Zhou
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Tayla M Olsen
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Glenda Daza
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Jose Ortega
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Kurtis R Cruz
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Nahum Smith
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Sara A Healy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland.,Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Washington, Seattle, Washington.,Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Jillian Neal
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Carolyn K Wallis
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Lisa Shelton
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Tracie VonGoedert Mankowski
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Sharon Wong-Madden
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Sebastian A Mikolajczak
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Ashley M Vaughan
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Stefan H I Kappe
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Matt Fishbaugher
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Will Betz
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Mark Kennedy
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Jen C C Hume
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Angela K Talley
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | | | | | | | | | - Anna Wald
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington
| | | | - Kirsten E Lyke
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Matthew Adams
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Gary A Fahle
- Microbiology Service, Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | | | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - James G Kublin
- Seattle Malaria Clinical Trials Center, Fred Hutch Cancer Research Center, Seattle, Washington.,Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Sean C Murphy
- Department of Microbiology, University of Washington, Seattle, Washington.,Seattle Malaria Clinical Trials Center, Fred Hutch Cancer Research Center, Seattle, Washington.,Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington.,Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
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35
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Metzger WG, Theurer A, Pfleiderer A, Molnar Z, Maihöfer-Braatting D, Bissinger AL, Sulyok Z, Köhler C, Egger-Adam D, Lalremruata A, Esen M, Lee Sim K, Hoffman S, Rabinovich R, Chaccour C, Alonso P, Mordmüller BG, Kremsner PG. Ivermectin for causal malaria prophylaxis: a randomised controlled human infection trial. Trop Med Int Health 2020; 25:380-386. [PMID: 31808594 DOI: 10.1111/tmi.13357] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE Ivermectin is safe and widely used for treating helminth infections. It also kills arthropods feeding on treated subjects, including malaria vectors. Thus, ivermectin mass drug administration as an additional tool for malaria control is being evaluated by WHO. As in vitro data, animal experiments and epidemiological observations suggest that ivermectin has a direct effect on the liver stages of the malaria parasite, this study was designed to assess the prophylactic effect of ivermectin on Plasmodium falciparum controlled human malaria infection. METHODS A total of 4 volunteers were randomised to placebo, and 8 volunteers were randomised to receive ivermectin 0.4 mg/kg, orally, once 2 h before being experimentally infected intravenously with 3200 P. falciparum sporozoites. The primary endpoint was time to parasitaemia detected by positive thick blood smear; RT-qPCR was performed in parallel. RESULTS All but one volunteer became thick blood smear positive between day 11 and day 12 after infection, and there was no significant effect of ivermectin on parasitaemia. CONCLUSION Ivermectin - at the dose used - has no clinically relevant activity against the pre-erythrocytic stages of P. falciparum.
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Affiliation(s)
- Wolfram G Metzger
- Institute for Tropical Medicine, German Center for Infection Research, Tübingen, Germany
| | - Antje Theurer
- Institute for Tropical Medicine, German Center for Infection Research, Tübingen, Germany
| | - Anne Pfleiderer
- Institute for Tropical Medicine, German Center for Infection Research, Tübingen, Germany
| | - Zsofia Molnar
- Institute for Tropical Medicine, German Center for Infection Research, Tübingen, Germany
| | | | - Alfred L Bissinger
- Institute for Tropical Medicine, German Center for Infection Research, Tübingen, Germany
| | - Zita Sulyok
- Institute for Tropical Medicine, German Center for Infection Research, Tübingen, Germany
| | - Carsten Köhler
- Institute for Tropical Medicine, German Center for Infection Research, Tübingen, Germany
| | - Diane Egger-Adam
- Institute for Tropical Medicine, German Center for Infection Research, Tübingen, Germany
| | - Albert Lalremruata
- Institute for Tropical Medicine, German Center for Infection Research, Tübingen, Germany
| | - Meral Esen
- Institute for Tropical Medicine, German Center for Infection Research, Tübingen, Germany
| | | | | | | | | | | | - Benjamin G Mordmüller
- Institute for Tropical Medicine, German Center for Infection Research, Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Peter G Kremsner
- Institute for Tropical Medicine, German Center for Infection Research, Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
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36
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Kapulu MC, Njuguna P, Hamaluba MM. Controlled Human Malaria Infection in Semi-Immune Kenyan Adults (CHMI-SIKA): a study protocol to investigate in vivo Plasmodium falciparum malaria parasite growth in the context of pre-existing immunity. Wellcome Open Res 2019; 3:155. [PMID: 31803847 PMCID: PMC6871356 DOI: 10.12688/wellcomeopenres.14909.2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2019] [Indexed: 01/09/2023] Open
Abstract
Malaria remains a major public health burden despite approval for implementation of a partially effective pre-erythrocytic malaria vaccine. There is an urgent need to accelerate development of a more effective multi-stage vaccine. Adults in malaria endemic areas may have substantial immunity provided by responses to the blood stages of malaria parasites, but field trials conducted on several blood-stage vaccines have not shown high levels of efficacy. We will use the controlled human malaria infection (CHMI) models with malaria-exposed volunteers to identify correlations between immune responses and parasite growth rates in vivo. Immune responses more strongly associated with control of parasite growth should be prioritized to accelerate malaria vaccine development. We aim to recruit up to 200 healthy adult volunteers from areas of differing malaria transmission in Kenya, and after confirming their health status through clinical examination and routine haematology and biochemistry, we will comprehensively characterize immunity to malaria using >100 blood-stage antigens. We will administer 3,200 aseptic, purified, cryopreserved Plasmodium falciparum sporozoites (PfSPZ Challenge) by direct venous inoculation. Serial quantitative polymerase chain reaction to measure parasite growth rate in vivo will be undertaken. Clinical and laboratory monitoring will be undertaken to ensure volunteer safety. In addition, we will also explore the perceptions and experiences of volunteers and other stakeholders in participating in a malaria volunteer infection study. Serum, plasma, peripheral blood mononuclear cells and whole blood will be stored to allow a comprehensive assessment of adaptive and innate host immunity. We will use CHMI in semi-immune adult volunteers to relate parasite growth outcomes with antibody responses and other markers of host immunity. Registration: ClinicalTrials.gov identifier NCT02739763.
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Affiliation(s)
- Melissa C. Kapulu
- KEMRI-Wellcome Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University Oxford, Oxford, UK
| | | | | | - CHMI-SIKA Study Team
- KEMRI-Wellcome Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University Oxford, Oxford, UK
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37
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Laurens MB, Berry AA, Travassos MA, Strauss K, Adams M, Shrestha B, Li T, Eappen A, Manoj A, Abebe Y, Murshedkar T, Gunasekera A, Richie TL, Lyke KE, Plowe CV, Kennedy JK, Potter GE, Deye GA, Sim BKL, Hoffman SL. Dose-Dependent Infectivity of Aseptic, Purified, Cryopreserved Plasmodium falciparum 7G8 Sporozoites in Malaria-Naive Adults. J Infect Dis 2019; 220:1962-1966. [PMID: 31419294 PMCID: PMC6834064 DOI: 10.1093/infdis/jiz410] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 08/13/2019] [Indexed: 12/11/2022] Open
Abstract
Direct venous inoculation of 3.2 × 103 aseptic, purified, cryopreserved, vialed Plasmodium falciparum (Pf) strain NF54 sporozoites, PfSPZ Challenge (NF54), has been used for controlled human malaria infection (CHMI) in the United States, 4 European countries, and 6 African countries. In nonimmune adults, this results in 100% infection rates. We conducted a double-blind, randomized, dose-escalation study to assess the infectivity of the 7G8 clone of Pf (PfSPZ Challenge [7G8]). Results showed dose-dependent infectivity from 43% for 8 × 102 PfSPZ to 100% for 4.8 × 103 PfSPZ. PfSPZ Challenge (7G8) will allow for more complete assessment by CHMI of antimalarial vaccines and drugs.
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Affiliation(s)
- Matthew B Laurens
- Malaria Research Group, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore
| | - Andrea A Berry
- Malaria Research Group, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore
| | - Mark A Travassos
- Malaria Research Group, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore
| | - Kathy Strauss
- Malaria Research Group, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore
| | - Matthew Adams
- Malaria Research Group, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore
| | - Biraj Shrestha
- Malaria Research Group, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore
| | - Tao Li
- Sanaria, Inc, Rockville, Maryland
| | | | | | | | | | | | | | - Kirsten E Lyke
- Malaria Research Group, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore
| | | | | | | | - Gregory A Deye
- Parasitology and International Programs Branch, Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
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38
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Loiseau C, Cooper MM, Doolan DL. Deciphering host immunity to malaria using systems immunology. Immunol Rev 2019; 293:115-143. [PMID: 31608461 DOI: 10.1111/imr.12814] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 09/18/2019] [Accepted: 09/20/2019] [Indexed: 12/11/2022]
Abstract
A century of conceptual and technological advances in infectious disease research has changed the face of medicine. However, there remains a lack of effective interventions and a poor understanding of host immunity to the most significant and complex pathogens, including malaria. The development of successful interventions against such intractable diseases requires a comprehensive understanding of host-pathogen immune responses. A major advance of the past decade has been a paradigm switch in thinking from the contemporary reductionist (gene-by-gene or protein-by-protein) view to a more holistic (whole organism) view. Also, a recognition that host-pathogen immunity is composed of complex, dynamic interactions of cellular and molecular components and networks that cannot be represented by any individual component in isolation. Systems immunology integrates the field of immunology with omics technologies and computational sciences to comprehensively interrogate the immune response at a systems level. Herein, we describe the system immunology toolkit and report recent studies deploying systems-level approaches in the context of natural exposure to malaria or controlled human malaria infection. We contribute our perspective on the potential of systems immunity for the rational design and development of effective interventions to improve global public health.
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Affiliation(s)
- Claire Loiseau
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Qld, Australia
| | - Martha M Cooper
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Qld, Australia
| | - Denise L Doolan
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Qld, Australia
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39
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Hoo R, Bruske E, Dimonte S, Zhu L, Mordmüller B, Sim BKL, Kremsner PG, Hoffman SL, Bozdech Z, Frank M, Preiser PR. Transcriptome profiling reveals functional variation in Plasmodium falciparum parasites from controlled human malaria infection studies. EBioMedicine 2019; 48:442-452. [PMID: 31521613 PMCID: PMC6838377 DOI: 10.1016/j.ebiom.2019.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/29/2019] [Accepted: 09/01/2019] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND The transcriptome of Plasmodium falciparum clinical isolates varies according to strain, mosquito bites, disease severity and clinical history. Therefore, it remains a challenge to directly interpret the parasite's transcriptomic information into a more general biological signature in a natural human malaria infection. These confounding variations can be potentially overcome with parasites derived from controlled-human malaria infection (CHMI) studies. METHODS We performed CHMI studies in healthy and immunologically naïve volunteers receiving the same P. falciparum strain ((Sanaria® PfSPZ Challenge (NF54)), but with different sporozoite dosage and route of infection. Parasites isolated from these volunteers at the day of patency were subjected to in vitro culture for several generations and synchronized ring-stage parasites were subjected to transcriptome profiling. FINDINGS We observed clear deviations between CHMI-derived parasites from volunteer groups receiving different PfSPZ dose and route. CHMI-derived parasites and the pre-mosquito strain used for PfSPZ generation showed significant transcriptional variability for gene clusters associated with malaria pathogenesis, immune evasion and transmission. These transcriptional variation signature clusters were also observed in the transcriptome of P. falciparum isolates from acute clinical infections. INTERPRETATION Our work identifies a previously unrecognized transcriptional pattern in malaria infections in a non-immune background. Significant transcriptome heterogeneity exits between parasites derived from human infections and the pre-mosquito strain, implying that the malaria parasites undergo a change in functional state to adapt to its host environment. Our work also highlights the potential use of transcriptomics data from CHMI study advance our understanding of malaria parasite adaptation and transmission in humans. FUND: This work is supported by German Israeli Foundation, German ministry for education and research, MOE Tier 1 from the Singapore Ministry of Education Academic Research Fund, Singapore Ministry of Health's National Medical Research Council, National Institute of Allergy and Infectious Diseases, National Institutes of Health, USA and the German Centre for Infection Research (Deutsches Zentrum für Infektionsforschung-DZIF).
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Affiliation(s)
- Regina Hoo
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Ellen Bruske
- Institute of Tropical Medicine, Wilhelmstr. 27, University of Tübingen, 72074 Tübingen, Germany
| | - Sandra Dimonte
- Institute of Tropical Medicine, Wilhelmstr. 27, University of Tübingen, 72074 Tübingen, Germany
| | - Lei Zhu
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Benjamin Mordmüller
- Institute of Tropical Medicine, Wilhelmstr. 27, University of Tübingen, 72074 Tübingen, Germany; German Center for Infection Research, partner site Tübingen, Germany
| | - B Kim Lee Sim
- Sanaria Inc, 9800 Medical Center Dr A209, Rockville, MD 20850, USA
| | - Peter G Kremsner
- Institute of Tropical Medicine, Wilhelmstr. 27, University of Tübingen, 72074 Tübingen, Germany; Centre de Recherches Médicales de Lambaréné, BP 242 Lambaréné, Gabon
| | | | - Zbynek Bozdech
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Matthias Frank
- Institute of Tropical Medicine, Wilhelmstr. 27, University of Tübingen, 72074 Tübingen, Germany.
| | - Peter R Preiser
- School of Biological Sciences, Nanyang Technological University, Singapore.
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40
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Ashton TD, Devine SM, Möhrle JJ, Laleu B, Burrows JN, Charman SA, Creek DJ, Sleebs BE. The Development Process for Discovery and Clinical Advancement of Modern Antimalarials. J Med Chem 2019; 62:10526-10562. [DOI: 10.1021/acs.jmedchem.9b00761] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Trent D. Ashton
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Shane M. Devine
- Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Jörg J. Möhrle
- Medicines for Malaria Venture, ICC, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Benoît Laleu
- Medicines for Malaria Venture, ICC, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Jeremy N. Burrows
- Medicines for Malaria Venture, ICC, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Susan A. Charman
- Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Darren J. Creek
- Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Brad E. Sleebs
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3052, Australia
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41
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Murphy SC, Duke ER, Shipman KJ, Jensen RL, Fong Y, Ferguson S, Janes HE, Gillespie K, Seilie AM, Hanron AE, Rinn L, Fishbaugher M, VonGoedert T, Fritzen E, Kappe SH, Chang M, Sousa JC, Marcsisin SR, Chalon S, Duparc S, Kerr N, Möhrle JJ, Andenmatten N, Rueckle T, Kublin JG. A Randomized Trial Evaluating the Prophylactic Activity of DSM265 Against Preerythrocytic Plasmodium falciparum Infection During Controlled Human Malarial Infection by Mosquito Bites and Direct Venous Inoculation. J Infect Dis 2019; 217:693-702. [PMID: 29216395 DOI: 10.1093/infdis/jix613] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 11/29/2017] [Indexed: 11/13/2022] Open
Abstract
Background DSM265 is a selective inhibitor of Plasmodium dihydroorotate dehydrogenase that fully protected against controlled human malarial infection (CHMI) by direct venous inoculation of Plasmodium falciparum sporozoites when administered 1 day before challenge and provided partial protection when administered 7 days before challenge. Methods A double-blinded, randomized, placebo-controlled trial was performed to assess safety, tolerability, pharmacokinetics, and efficacy of 1 oral dose of 400 mg of DSM265 before CHMI. Three cohorts were studied, with DSM265 administered 3 or 7 days before direct venous inoculation of sporozoites or 7 days before 5 bites from infected mosquitoes. Results DSM265-related adverse events consisted of mild-to-moderate headache and gastrointestinal symptoms. DSM265 concentrations were consistent with pharmacokinetic models (mean area under the curve extrapolated to infinity, 1707 µg*h/mL). Placebo-treated participants became positive by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and were treated 7-10 days after CHMI. Among DSM265-treated subjects, 2 of 6 in each cohort were sterilely protected. DSM265-treated recipients had longer times to development of parasitemia than placebo-treated participants (P < .004). Conclusions This was the first CHMI study of a novel antimalarial compound to compare direct venous inoculation of sporozoites and mosquito bites. Times to qRT-PCR positivity and treatment were comparable for both routes. DSM265 given 3 or 7 days before CHMI was safe and well tolerated but sterilely protected only one third of participants.
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Affiliation(s)
- Sean C Murphy
- Department of Laboratory Medicine, University of Washington, Seattle, Washington.,Department of Microbiology, University of Washington, Seattle, Washington.,Center for Emerging and Re-emerging Infectious Diseases, Seattle, Washington.,Seattle Malaria Clinical Trials Center, Fred Hutchinson Cancer Research Center, Seattle, Washington.,Human Challenge Center, Center for Infectious Disease Research, Seattle, Washington
| | - Elizabeth R Duke
- Department of Medicine, University of Washington, Seattle, Washington.,Seattle Malaria Clinical Trials Center, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Kelly J Shipman
- Seattle Malaria Clinical Trials Center, Fred Hutchinson Cancer Research Center, Seattle, Washington.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Ryan L Jensen
- Seattle Malaria Clinical Trials Center, Fred Hutchinson Cancer Research Center, Seattle, Washington.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Youyi Fong
- Seattle Malaria Clinical Trials Center, Fred Hutchinson Cancer Research Center, Seattle, Washington.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Sue Ferguson
- Seattle Malaria Clinical Trials Center, Fred Hutchinson Cancer Research Center, Seattle, Washington.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Holly E Janes
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Kevin Gillespie
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Annette M Seilie
- Department of Laboratory Medicine, University of Washington, Seattle, Washington
| | - Amelia E Hanron
- Department of Laboratory Medicine, University of Washington, Seattle, Washington
| | - Laurie Rinn
- Seattle Malaria Clinical Trials Center, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Matthew Fishbaugher
- Human Challenge Center, Center for Infectious Disease Research, Seattle, Washington
| | - Tracie VonGoedert
- Human Challenge Center, Center for Infectious Disease Research, Seattle, Washington
| | - Emma Fritzen
- Human Challenge Center, Center for Infectious Disease Research, Seattle, Washington
| | - Stefan H Kappe
- Human Challenge Center, Center for Infectious Disease Research, Seattle, Washington
| | - Ming Chang
- Department of Laboratory Medicine, University of Washington, Seattle, Washington
| | - Jason C Sousa
- Walter Reed Army Institute of Research, Silver Spring, Maryland
| | | | | | | | - Nicola Kerr
- Medicines for Malaria Venture, Geneva, Switzerland
| | | | | | | | - James G Kublin
- Department of Global Health, University of Washington, Seattle, Washington.,Seattle Malaria Clinical Trials Center, Fred Hutchinson Cancer Research Center, Seattle, Washington.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
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42
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Cooper MM, Loiseau C, McCarthy JS, Doolan DL. Human challenge models: tools to accelerate the development of malaria vaccines. Expert Rev Vaccines 2019; 18:241-251. [PMID: 30732492 DOI: 10.1080/14760584.2019.1580577] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Malaria challenge models, where healthy human volunteers are intentionally infected with Plasmodium species parasites under controlled conditions, can be undertaken in several well-defined ways. These challenge models enable evaluation of the kinetics of parasite growth and clearance, host-pathogen interactions and the host immune response. They can facilitate discovery of candidate diagnostic biomarkers and novel vaccine targets. As translational tools they can facilitate testing of candidate vaccines and drugs and evaluation of diagnostic tests. AREAS COVERED Until recently, malaria human challenge models have been limited to only a few Plasmodium falciparum strains and used exclusively in malaria-naïve volunteers in non-endemic regions. Several recent advances include the use of alternate P. falciparum strains and other species of Plasmodia, as well as strains attenuated by chemical, radiation or genetic modification, and the conduct of studies in pre-exposed individuals. Herein, we discuss how this diversification is enabling more thorough vaccine efficacy testing and informing rational vaccine development. EXPERT OPINION The ability to comprehensively evaluate vaccine efficacy in controlled settings will continue to accelerate the translation of candidate malaria vaccines to the clinic, and inform the development and optimisation of potential vaccines that would be effective against multiple strains in geographically and demographically diverse settings.
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Affiliation(s)
- Martha M Cooper
- a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia
| | - Claire Loiseau
- a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia
| | - James S McCarthy
- b Infectious Diseases Programme , QIMR Berghofer Medical Research Institute , Brisbane , Australia
| | - Denise L Doolan
- a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia
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O'Brochta DA, Alford R, Harrell R, Aluvihare C, Eappen AG, Li T, Chakravarty S, Sim BKL, Hoffman SL, Billingsley PF. Is Saglin a mosquito salivary gland receptor for Plasmodium falciparum? Malar J 2019; 18:2. [PMID: 30602380 PMCID: PMC6317240 DOI: 10.1186/s12936-018-2634-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 12/20/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Saglin, a 100 kDa protein composed of two 50 kDa homodimers, is present in the salivary glands of Anopheles gambiae and has been considered an essential receptor for sporozoites (SPZ) of Plasmodium berghei and Plasmodium falciparum (Pf), allowing SPZ to recognize, bind to, and infect mosquito salivary glands. Spatial and temporal patterns of Saglin expression reported here, however, suggest that this model does not fully describe the Saglin-SPZ interaction. RESULTS Saglin protein was detected by indirect immunofluorescence microscopy only in the medial and proximal-lateral lobes, but not in the distal-lateral lobes, of the salivary glands of An. gambiae; the pattern of expression was independent of mosquito age or physiological state. These results were confirmed by steady-state Saglin transcript and protein expression using qRT-PCR and Western-blot analysis, respectively. Saglin was localized to the basal surface of the cells of the medial lobes and was undetectable elsewhere (intracellularly, on the lateral or apical membranes, the cells' secretory vacuoles, or in the salivary duct). In the cells of the proximal lateral lobes of the salivary glands, Saglin was distinctly intracellular and was not localized to any of the cell surfaces. Transgenic Anopheles stephensi were produced that expressed An. gambiae Saglin in the distal lateral lobes of the salivary gland. Additional Saglin expression did not enhance infection by PfSPZ compared to non-transgenic siblings fed on the same gametocyte-containing blood meal. CONCLUSIONS The absence of Saglin in the distal lateral lobes of the salivary glands, a primary destination for SPZ, suggests Saglin is not an essential receptor for Plasmodium SPZ. The lack of any correlation between increased Saglin expression in the distal lateral lobes of the salivary glands of transgenic An. stephensi and PfSPZ infection is also consistent with Saglin not being an essential salivary gland receptor for Plasmodium SPZ.
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Affiliation(s)
- David A O'Brochta
- Department of Entomology and The Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, 9600 Gudelsky Drive, Rockville, MD, 20850, USA.,Foundation for the National Institutes of Health, 11400 Rockville Pike, Suite 600, North Bethesda, MD, 20852, USA
| | - Robert Alford
- Department of Entomology and The Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, 9600 Gudelsky Drive, Rockville, MD, 20850, USA
| | - Robert Harrell
- University of Maryland Insect Transformation Facility, The Institute for Bioscience and Biotechnology Research, 9600 Gudelsky Drive, Rockville, MD, 20850, USA
| | - Channa Aluvihare
- University of Maryland Insect Transformation Facility, The Institute for Bioscience and Biotechnology Research, 9600 Gudelsky Drive, Rockville, MD, 20850, USA
| | - Abraham G Eappen
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Tao Li
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Sumana Chakravarty
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - B Kim Lee Sim
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Stephen L Hoffman
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Peter F Billingsley
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA.
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44
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Kapulu MC, Njuguna P, Hamaluba MM. Controlled Human Malaria Infection in Semi-Immune Kenyan Adults (CHMI-SIKA): a study protocol to investigate in vivo Plasmodium falciparum malaria parasite growth in the context of pre-existing immunity. Wellcome Open Res 2018; 3:155. [PMID: 31803847 PMCID: PMC6871356 DOI: 10.12688/wellcomeopenres.14909.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/22/2018] [Indexed: 10/20/2023] Open
Abstract
Malaria remains a major public health burden despite approval for implementation of a partially effective pre-erythrocytic malaria vaccine. There is an urgent need to accelerate development of a more effective multi-stage vaccine. Adults in malaria endemic areas may have substantial immunity provided by responses to the blood stages of malaria parasites, but field trials conducted on several blood-stage vaccines have not shown high levels of efficacy. We will use controlled human malaria infection (CHMI) studies with malaria-exposed volunteers to identify correlations between immune responses and parasite growth rates in vivo. Immune responses more strongly associated with control of parasite growth should be prioritized to accelerate malaria vaccine development. We aim to recruit up to 200 healthy adult volunteers from areas of differing malaria transmission in Kenya, and after confirming their health status through clinical examination and routine haematology and biochemistry, we will comprehensively characterize immunity to malaria using >100 blood-stage antigens. We will administer 3,200 aseptic, purified, cryopreserved Plasmodium falciparum sporozoites (PfSPZ Challenge) by direct venous inoculation. Serial quantitative polymerase chain reaction to measure parasite growth rate in vivo will be undertaken. Clinical and laboratory monitoring will be undertaken to ensure volunteer safety. In addition, we will also explore the perceptions and experiences of volunteers and other stakeholders in participating in a malaria volunteer infection study. Serum, plasma, peripheral blood mononuclear cells and extracted DNA will be stored to allow a comprehensive assessment of adaptive and innate host immunity. We will use CHMI in semi-immune adult volunteers to relate parasite growth outcomes with antibody responses and other markers of host immunity. Registration: ClinicalTrials.gov identifier NCT02739763.
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Affiliation(s)
- Melissa C. Kapulu
- KEMRI-Wellcome Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University Oxford, Oxford, UK
| | | | | | - CHMI-SIKA Study Team
- KEMRI-Wellcome Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University Oxford, Oxford, UK
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Murphy SC, Ishizuka AS, Billman ZP, Olsen TM, Seilie AM, Chang M, Smith N, Chuenchob V, Chakravarty S, Sim BKL, Kappe SHI, Hoffman SL, Seder RA. Plasmodium 18S rRNA of intravenously administered sporozoites does not persist in peripheral blood. Malar J 2018; 17:275. [PMID: 30053881 PMCID: PMC6062992 DOI: 10.1186/s12936-018-2422-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/19/2018] [Indexed: 01/14/2023] Open
Abstract
Background Plasmodium 18S rRNA is a biomarker used to monitor blood-stage infections in malaria clinical trials. Plasmodium sporozoites also express this biomarker, and there is conflicting evidence about how long sporozoite-derived 18S rRNA persists in peripheral blood. If present in blood for an extended timeframe, sporozoite-derived 18S rRNA could complicate use as a blood-stage biomarker. Methods Blood samples from Plasmodium yoelii infected mice were tested for Plasmodium 18S rRNA and their coding genes (rDNA) using sensitive quantitative reverse transcription PCR and quantitative PCR assays, respectively. Blood and tissues from Plasmodium falciparum sporozoite (PfSPZ)-infected rhesus macaques were similarly tested. Results In mice, when P. yoelii sporozoite inoculation and blood collection were performed at the same site (tail vein), low level rDNA positivity persisted for 2 days post-infection. Compared to intact parasites with high rRNA-to-rDNA ratios, this low level positivity was accompanied by no increase in rRNA-to-rDNA, indicating detection of residual, non-viable parasite rDNA. When P. yoelii sporozoites were administered via the retro-orbital vein and blood sampled by cardiac puncture, neither P. yoelii 18S rRNA nor rDNA were detected 24 h post-infection. Similarly, there was no P. falciparum 18S rRNA detected in blood of rhesus macaques 3 days after intravenous injection with extremely high doses of PfSPZ. Plasmodium 18S rRNA in the rhesus livers increased by approximately 101-fold from 3 to 6 days post infection, indicating liver-stage proliferation. Conclusions Beyond the first few hours after injection, sporozoite-derived Plasmodium 18S rRNA was not detected in peripheral blood. Diagnostics based on 18S rRNA are unlikely to be confounded by sporozoite inocula in human clinical trials.
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Affiliation(s)
- Sean C Murphy
- Departments of Laboratory Medicine and Microbiology, University of Washington, 750 Republican St., E630, Seattle, WA, 98109, USA. .,Center for Emerging and Re-emerging Infectious Diseases, University of Washington, 750 Republican St., Seattle, WA, 98109, USA.
| | - Andrew S Ishizuka
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Building 40, Room 3512, 40 Convent Drive, Bethesda, MD, 20814, USA
| | - Zachary P Billman
- Departments of Laboratory Medicine and Microbiology, University of Washington, 750 Republican St., E630, Seattle, WA, 98109, USA
| | - Tayla M Olsen
- Departments of Laboratory Medicine and Microbiology, University of Washington, 750 Republican St., E630, Seattle, WA, 98109, USA
| | - Annette M Seilie
- Departments of Laboratory Medicine and Microbiology, University of Washington, 750 Republican St., E630, Seattle, WA, 98109, USA
| | - Ming Chang
- Departments of Laboratory Medicine and Microbiology, University of Washington, 750 Republican St., E630, Seattle, WA, 98109, USA
| | - Nahum Smith
- Departments of Laboratory Medicine and Microbiology, University of Washington, 750 Republican St., E630, Seattle, WA, 98109, USA
| | - Vorada Chuenchob
- Center for Infectious Disease Research, 307 Westlake Ave N #500, Seattle, WA, 98109, USA
| | - Sumana Chakravarty
- Sanaria, Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - B Kim Lee Sim
- Sanaria, Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Stefan H I Kappe
- Center for Infectious Disease Research, 307 Westlake Ave N #500, Seattle, WA, 98109, USA
| | - Stephen L Hoffman
- Sanaria, Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Robert A Seder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Building 40, Room 3512, 40 Convent Drive, Bethesda, MD, 20814, USA
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Jongo SA, Shekalaghe SA, Church LWP, Ruben AJ, Schindler T, Zenklusen I, Rutishauser T, Rothen J, Tumbo A, Mkindi C, Mpina M, Mtoro AT, Ishizuka AS, Kassim KR, Milando FA, Qassim M, Juma OA, Mwakasungula S, Simon B, James ER, Abebe Y, Kc N, Chakravarty S, Saverino E, Bakari BM, Billingsley PF, Seder RA, Daubenberger C, Sim BKL, Richie TL, Tanner M, Abdulla S, Hoffman SL. Safety, Immunogenicity, and Protective Efficacy against Controlled Human Malaria Infection of Plasmodium falciparum Sporozoite Vaccine in Tanzanian Adults. Am J Trop Med Hyg 2018; 99:338-349. [PMID: 29943719 PMCID: PMC6090339 DOI: 10.4269/ajtmh.17-1014] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
We are using controlled human malaria infection (CHMI) by direct venous inoculation (DVI) of cryopreserved, infectious Plasmodium falciparum (Pf) sporozoites (SPZ) (PfSPZ Challenge) to try to reduce time and costs of developing PfSPZ Vaccine to prevent malaria in Africa. Immunization with five doses at 0, 4, 8, 12, and 20 weeks of 2.7 × 105 PfSPZ of PfSPZ Vaccine gave 65% vaccine efficacy (VE) at 24 weeks against mosquito bite CHMI in U.S. adults and 52% (time to event) or 29% (proportional) VE over 24 weeks against naturally transmitted Pf in Malian adults. We assessed the identical regimen in Tanzanians for VE against PfSPZ Challenge. Twenty- to thirty-year-old men were randomized to receive five doses normal saline or PfSPZ Vaccine in a double-blind trial. Vaccine efficacy was assessed 3 and 24 weeks later. Adverse events were similar in vaccinees and controls. Antibody responses to Pf circumsporozoite protein were significantly lower than in malaria-naïve Americans, but significantly higher than in Malians. All 18 controls developed Pf parasitemia after CHMI. Four of 20 (20%) vaccinees remained uninfected after 3 week CHMI (P = 0.015 by time to event, P = 0.543 by proportional analysis) and all four (100%) were uninfected after repeat 24 week CHMI (P = 0.005 by proportional, P = 0.004 by time to event analysis). Plasmodium falciparum SPZ Vaccine was safe, well tolerated, and induced durable VE in four subjects. Controlled human malaria infection by DVI of PfSPZ Challenge appeared more stringent over 24 weeks than mosquito bite CHMI in United States or natural exposure in Malian adults, thereby providing a rigorous test of VE in Africa.
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Affiliation(s)
- Said A Jongo
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Seif A Shekalaghe
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | | | | | - Tobias Schindler
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute (Swiss TPH), Basel, Switzerland
| | - Isabelle Zenklusen
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute (Swiss TPH), Basel, Switzerland
| | - Tobias Rutishauser
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute (Swiss TPH), Basel, Switzerland
| | - Julian Rothen
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute (Swiss TPH), Basel, Switzerland
| | - Anneth Tumbo
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Catherine Mkindi
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Maximillian Mpina
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Ali T Mtoro
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Andrew S Ishizuka
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | | | - Florence A Milando
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Munira Qassim
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Omar A Juma
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Solomon Mwakasungula
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Beatus Simon
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | | | | | | | | | | | - Bakari M Bakari
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | | | - Robert A Seder
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Claudia Daubenberger
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute (Swiss TPH), Basel, Switzerland
| | - B Kim Lee Sim
- Protein Potential LLC, Rockville, Maryland.,Sanaria Inc., Rockville, Maryland
| | | | - Marcel Tanner
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute (Swiss TPH), Basel, Switzerland
| | - Salim Abdulla
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
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Ubillos I, Jiménez A, Vidal M, Bowyer PW, Gaur D, Dutta S, Gamain B, Coppel R, Chauhan V, Lanar D, Chitnis C, Angov E, Beeson J, Cavanagh D, Campo JJ, Aguilar R, Dobaño C. Optimization of incubation conditions of Plasmodium falciparum antibody multiplex assays to measure IgG, IgG 1-4, IgM and IgE using standard and customized reference pools for sero-epidemiological and vaccine studies. Malar J 2018; 17:219. [PMID: 29859096 PMCID: PMC5984756 DOI: 10.1186/s12936-018-2369-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/28/2018] [Indexed: 12/15/2022] Open
Abstract
Background The quantitative suspension array technology (qSAT) is a useful platform for malaria immune marker discovery. However, a major challenge for large sero-epidemiological and malaria vaccine studies is the comparability across laboratories, which requires the access to standardized control reagents for assay optimization, to monitor performance and improve reproducibility. Here, the Plasmodium falciparum antibody reactivities of the newly available WHO reference reagent for anti-malaria human plasma (10/198) and of additional customized positive controls were examined with seven in-house qSAT multiplex assays measuring IgG, IgG1–4 subclasses, IgM and IgE against a panel of 40 antigens. The different positive controls were tested at different incubation times and temperatures (4 °C overnight, 37 °C 2 h, room temperature 1 h) to select the optimal conditions. Results Overall, the WHO reference reagent had low IgG2, IgG4, IgM and IgE, and also low anti-CSP antibody levels, thus this reagent was enriched with plasmas from RTS,S-vaccinated volunteers to be used as standard for CSP-based vaccine studies. For the IgM assay, another customized plasma pool prepared with samples from malaria primo-infected adults with adequate IgM levels proved to be more adequate as a positive control. The range and magnitude of IgG and IgG1–4 responses were highest when the WHO reference reagent was incubated with antigen-coupled beads at 4 °C overnight. IgG levels measured in the negative control did not vary between incubations at 37 °C 2 h and 4 °C overnight, indicating no difference in unspecific binding. Conclusions With this study, the immunogenicity profile of the WHO reference reagent, including seven immunoglobulin isotypes and subclasses, and more P. falciparum antigens, also those included in the leading RTS,S malaria vaccine, was better characterized. Overall, incubation of samples at 4 °C overnight rendered the best performance for antibody measurements against the antigens tested. Although the WHO reference reagent performed well to measure IgG to the majority of the common P. falciparum blood stage antigens tested, customized pools may need to be used as positive controls depending on the antigens (e.g. pre-erythrocytic proteins of low natural immunogenicity) and isotypes/subclasses (e.g. IgM) under study. Electronic supplementary material The online version of this article (10.1186/s12936-018-2369-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Itziar Ubillos
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Catalonia, Spain
| | - Alfons Jiménez
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Catalonia, Spain.,CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain
| | - Marta Vidal
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Catalonia, Spain
| | - Paul W Bowyer
- Bacteriology Division, MHRA-NIBSC, South Mimms, Potter Bars, EN6 3QG, UK
| | - Deepak Gaur
- Laboratory of Malaria and Vaccine Research, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India.,Malaria Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Sheetij Dutta
- U.S. Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Benoit Gamain
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge UMR_S1134, Laboratoire d'Excellence GR-Ex, Paris, France
| | - Ross Coppel
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Virander Chauhan
- Malaria Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - David Lanar
- U.S. Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Chetan Chitnis
- Malaria Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Evelina Angov
- U.S. Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - James Beeson
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia
| | - David Cavanagh
- Institute of Immunology & Infection Research and Centre for Immunity, Infection & Evolution, Ashworth Laboratories, School of Biological Sciences, University of Edinburgh, King's Buildings, Charlotte Auerbach Rd, Edinburgh, EH9 3FL, UK
| | - Joseph J Campo
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Catalonia, Spain
| | - Ruth Aguilar
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Catalonia, Spain
| | - Carlota Dobaño
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Catalonia, Spain.
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McCall MBB, Wammes LJ, Langenberg MCC, van Gemert GJ, Walk J, Hermsen CC, Graumans W, Koelewijn R, Franetich JF, Chishimba S, Gerdsen M, Lorthiois A, van de Vegte M, Mazier D, Bijker EM, van Hellemond JJ, van Genderen PJJ, Sauerwein RW. Infectivity of Plasmodium falciparum sporozoites determines emerging parasitemia in infected volunteers. Sci Transl Med 2018. [PMID: 28637923 DOI: 10.1126/scitranslmed.aag2490] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Malaria sporozoites must first undergo intrahepatic development before a pathogenic blood-stage infection is established. The success of infection depends on host and parasite factors. In healthy human volunteers undergoing controlled human malaria infection (CHMI), we directly compared three clinical Plasmodium falciparum isolates for their ability to infect primary human hepatocytes in vitro and to drive the production of blood-stage parasites in vivo. Our data show a correlation between the efficiency of strain-specific sporozoite invasion of human hepatocytes and the dynamics of patent parasitemia in study subjects, highlighting intrinsic differences in infectivity among P. falciparum isolates from distinct geographical locales. The observed heterogeneity in infectivity among strains underscores the value of assessing the protective efficacy of candidate malaria vaccines against heterologous strains in the CHMI model.
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Affiliation(s)
- Matthew B B McCall
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, Netherlands
| | - Linda J Wammes
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, Netherlands
| | | | - Geert-Jan van Gemert
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Jona Walk
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Cornelus C Hermsen
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Wouter Graumans
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Rob Koelewijn
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, Netherlands.,Institute for Tropical Diseases, Harbour Hospital, Rotterdam, Netherlands
| | - Jean-François Franetich
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U1135, CNRS ERL 8255, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), 91 Bd de l'hôpital, F-75013 Paris, France
| | - Sandra Chishimba
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, Netherlands
| | - Max Gerdsen
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Audrey Lorthiois
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U1135, CNRS ERL 8255, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), 91 Bd de l'hôpital, F-75013 Paris, France
| | - Marga van de Vegte
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Dominique Mazier
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U1135, CNRS ERL 8255, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), 91 Bd de l'hôpital, F-75013 Paris, France.,AP-HP, Groupe hospitalier La Pitié-Salpêtrière, Service de Parasitologie Mycologie, F-75013 Paris, France
| | - Else M Bijker
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Jaap J van Hellemond
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, Netherlands
| | | | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands.
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Lell B, Mordmüller B, Dejon Agobe JC, Honkpehedji J, Zinsou J, Mengue JB, Loembe MM, Adegnika AA, Held J, Lalremruata A, Nguyen TT, Esen M, KC N, Ruben AJ, Chakravarty S, Lee Sim BK, Billingsley PF, James ER, Richie TL, Hoffman SL, Kremsner PG. Impact of Sickle Cell Trait and Naturally Acquired Immunity on Uncomplicated Malaria after Controlled Human Malaria Infection in Adults in Gabon. Am J Trop Med Hyg 2018; 98:508-515. [PMID: 29260650 PMCID: PMC5929186 DOI: 10.4269/ajtmh.17-0343] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 11/02/2017] [Indexed: 11/07/2022] Open
Abstract
Controlled human malaria infection (CHMI) by direct venous inoculation (DVI) with 3,200 cryopreserved Plasmodium falciparum sporozoites (PfSPZ) consistently leads to parasitemia and malaria symptoms in malaria-naive adults. We used CHMI by DVI to investigate infection rates, parasite kinetics, and malaria symptoms in lifelong malaria-exposed (semi-immune) Gabonese adults with and without sickle cell trait. Eleven semi-immune Gabonese with normal hemoglobin (IA), nine with sickle cell trait (IS), and five nonimmune European controls with normal hemoglobin (NI) received 3,200 PfSPZ by DVI and were followed 28 days for parasitemia by thick blood smear (TBS) and quantitative polymerase chain reaction (qPCR) and for malaria symptoms. End points were time to parasitemia and parasitemia plus symptoms. PfSPZ Challenge was well tolerated and safe. Five of the five (100%) NI, 7/11 (64%) IA, and 5/9 (56%) IS volunteers developed parasitemia by TBS, and 5/5 (100%) NI, 9/11 (82%) IA, and 7/9 (78%) IS by qPCR, respectively. The time to parasitemia by TBS was longer in IA (geometric mean 16.9 days) and IS (19.1 days) than in NA (12.6 days) volunteers (P = 0.016, 0.021, respectively). Five of the five, 6/9, and 1/7 volunteers with parasitemia developed symptoms (P = 0.003, NI versus IS). Naturally adaptive immunity (NAI) to malaria significantly prolonged the time to parasitemia. Sickle cell trait seemed to prolong it further. NAI plus sickle cell trait, but not NAI alone, significantly reduced symptom rate. Twenty percent (4/20) semi-immunes demonstrated sterile protective immunity. Standardized CHMI with PfSPZ Challenge is a powerful tool for dissecting the impact of innate and naturally acquired adaptive immunity on malaria.
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Affiliation(s)
- Bertrand Lell
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research (DZIF), Tübingen, Germany
| | - Benjamin Mordmüller
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research (DZIF), Tübingen, Germany
| | | | | | - Jeannot Zinsou
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Juliana Boex Mengue
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research (DZIF), Tübingen, Germany
| | | | - Ayola Akim Adegnika
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research (DZIF), Tübingen, Germany
| | - Jana Held
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research (DZIF), Tübingen, Germany
| | - Albert Lalremruata
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research (DZIF), Tübingen, Germany
| | - The Trong Nguyen
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research (DZIF), Tübingen, Germany
| | - Meral Esen
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research (DZIF), Tübingen, Germany
| | - Natasha KC
- Sanaria Inc., Rockville, Maryland
- Protein Potential, LLC, Rockville, Maryland
| | | | | | | | | | | | | | - Stephen L. Hoffman
- Sanaria Inc., Rockville, Maryland
- Protein Potential, LLC, Rockville, Maryland
| | - Peter G. Kremsner
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research (DZIF), Tübingen, Germany
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50
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Olotu A, Urbano V, Hamad A, Eka M, Chemba M, Nyakarungu E, Raso J, Eburi E, Mandumbi DO, Hergott D, Maas CD, Ayekaba MO, Milang DN, Rivas MR, Schindler T, Embon OM, Ruben AJ, Saverino E, Abebe Y, Kc N, James ER, Murshedkar T, Manoj A, Chakravarty S, Li M, Adams M, Schwabe C, Segura JL, Daubenberger C, Tanner M, Richie TL, Billingsley PF, Lee Sim BK, Abdulla S, Hoffman SL. Advancing Global Health through Development and Clinical Trials Partnerships: A Randomized, Placebo-Controlled, Double-Blind Assessment of Safety, Tolerability, and Immunogenicity of PfSPZ Vaccine for Malaria in Healthy Equatoguinean Men. Am J Trop Med Hyg 2018; 98:308-318. [PMID: 29141739 PMCID: PMC5928718 DOI: 10.4269/ajtmh.17-0449] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Equatorial Guinea (EG) has implemented a successful malaria control program on Bioko Island. A highly effective vaccine would be an ideal complement to this effort and could lead to halting transmission and eliminating malaria. Sanaria® PfSPZ Vaccine (Plasmodium falciparum sporozoite Vaccine) is being developed for this purpose. To begin the process of establishing the efficacy of and implementing a PfSPZ Vaccine mass vaccination program in EG, we decided to conduct a series of clinical trials of PfSPZ Vaccine on Bioko Island. Because no clinical trial had ever been conducted in EG, we first successfully established the ethical, regulatory, quality, and clinical foundation for conducting trials. We now report the safety, tolerability, and immunogenicity results of the first clinical trial in the history of the country. Thirty adult males were randomized in the ratio 2:1 to receive three doses of 2.7 × 105 PfSPZ of PfSPZ Vaccine (N = 20) or normal saline placebo (N = 10) by direct venous inoculation at 8-week intervals. The vaccine was safe and well tolerated. Seventy percent, 65%, and 45% of vaccinees developed antibodies to Plasmodium falciparum (Pf) circumsporozoite protein (PfCSP) by enzyme-linked immunosorbent assay, PfSPZ by automated immunofluorescence assay, and PfSPZ by inhibition of sporozoite invasion assay, respectively. Antibody responses were significantly lower than responses in U.S. adults who received the same dosage regimen, but not significantly different than responses in young adult Malians. Based on these results, a clinical trial enrolling 135 subjects aged 6 months to 65 years has been initiated in EG; it includes PfSPZ Vaccine and first assessment in Africa of PfSPZ-CVac. ClinicalTrials.gov identifier: NCT02418962.
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Affiliation(s)
- Ally Olotu
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Equatorial Guinea
- Ifakara Health Institute, Dar es Salaam, Tanzania
| | - Vicente Urbano
- Ministry of Health and Social Welfare, Malabo, Bioko Norte, Equatorial Guinea
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Equatorial Guinea
| | - Ali Hamad
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Equatorial Guinea
- Ifakara Health Institute, Dar es Salaam, Tanzania
| | - Martin Eka
- Ministry of Health and Social Welfare, Malabo, Bioko Norte, Equatorial Guinea
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Equatorial Guinea
| | - Mwajuma Chemba
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Equatorial Guinea
- Ifakara Health Institute, Dar es Salaam, Tanzania
| | - Elizabeth Nyakarungu
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Equatorial Guinea
- Ifakara Health Institute, Dar es Salaam, Tanzania
| | - Jose Raso
- Ministry of Health and Social Welfare, Malabo, Bioko Norte, Equatorial Guinea
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Equatorial Guinea
| | - Esther Eburi
- Medical Care Development International, Silver Spring, Maryland
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Equatorial Guinea
| | - Dolores O Mandumbi
- Ministry of Health and Social Welfare, Malabo, Bioko Norte, Equatorial Guinea
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Equatorial Guinea
| | - Dianna Hergott
- Medical Care Development International, Silver Spring, Maryland
| | - Carl D Maas
- Marathon EG Production Ltd, Punta Europa, Bioko Norte, Malabo, Equatorial Guinea
| | - Mitoha O Ayekaba
- Marathon EG Production Ltd, Punta Europa, Bioko Norte, Malabo, Equatorial Guinea
| | - Diosdado N Milang
- Ministry of Health and Social Welfare, Malabo, Bioko Norte, Equatorial Guinea
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Equatorial Guinea
| | - Matilde R Rivas
- Ministry of Health and Social Welfare, Malabo, Bioko Norte, Equatorial Guinea
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Equatorial Guinea
| | | | - Oscar M Embon
- La Paz Medical Center, Sipopo, Bioko Island, Equatorial Guinea
| | | | | | | | | | | | | | | | | | | | - Matthew Adams
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | | | - J Luis Segura
- Medical Care Development International, Silver Spring, Maryland
| | | | - Marcel Tanner
- University of Basel, Basel, Switzerland
- Swiss Tropical and Public Health Institute, Basel, Switzerland
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