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Duffy PE, Gorres JP, Healy SA, Fried M. Malaria vaccines: a new era of prevention and control. Nat Rev Microbiol 2024:10.1038/s41579-024-01065-7. [PMID: 39025972 DOI: 10.1038/s41579-024-01065-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2024] [Indexed: 07/20/2024]
Abstract
Malaria killed over 600,000 people in 2022, a death toll that has not improved since 2015. Additionally, parasites and mosquitoes resistant to existing interventions are spreading across Africa and other regions. Vaccines offer hope to reduce the mortality burden: the first licensed malaria vaccines, RTS,S and R21, will be widely deployed in 2024 and should substantially reduce childhood deaths. In this Review, we provide an overview of the malaria problem and the Plasmodium parasite, then describe the RTS,S and R21 vaccines (the first vaccines for any human parasitic disease), summarizing their benefits and limitations. We explore next-generation vaccines designed using new knowledge of malaria pathogenesis and protective immunity, which incorporate antigens and platforms to elicit effective immune responses against different parasite stages in human or mosquito hosts. We describe a decision-making process that prioritizes malaria vaccine candidates for development in a resource-constrained environment. Future vaccines might improve upon the protective efficacy of RTS,S or R21 for children, or address the wider malaria scourge by preventing pregnancy malaria, reducing the burden of Plasmodium vivax or accelerating malaria elimination.
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Affiliation(s)
- Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| | - J Patrick Gorres
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Sara A Healy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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2
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Abuelazm MT, Elzeftawy MA, Kamal MA, Badr H, Gamal M, Aboulgheit M, Abdelazeem B, Abd-Elsalam S, Abouzid M. Protective efficacy and safety of radiation-attenuated and chemo-attenuated Plasmodium Falciparum sporozoite vaccines against controlled and natural malaria infection: a systematic review and meta-analysis of randomized controlled trials. Infection 2024; 52:707-722. [PMID: 38319556 DOI: 10.1007/s15010-024-02174-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 01/01/2024] [Indexed: 02/07/2024]
Abstract
BACKGROUND AND OBJECTIVE Despite the significant burden of Plasmodium falciparum (Pf) malaria and the licensure of two vaccines for use in infants and young children that are partially effective in preventing clinical malaria caused by Pf, a highly effective vaccine against Pf infection is still lacking. Live attenuated vaccines using Pf sporozoites as the immunogen (PfSPZ Vaccines) hold promise for addressing this gap. Here we review the safety and efficacy of two of the most promising PfSPZ approaches: PfSPZ Vaccine (radiation attenuated PfSPZ) and PfSPZ-CVac (chemo-attenuated PfSPZ). METHODS We conducted a systematic review and meta-analysis by searching PubMed, EMBASE, SCOPUS, CENTRAL, and WOS until 22nd December 2021. We included randomized controlled trials (RCTs) of these two vaccine approaches that measured protection against parasitaemia following controlled human malaria infection (CHMI) in malaria-naive and malaria-exposed adults or following exposure to naturally transmitted Pf malaria in African adults and children (primary outcome) and that also measured the incidence of solicited and unsolicited adverse events as indicators of safety and tolerability after vaccination (secondary outcome). We included randomized controlled trials (RCTs) that measured the detected parasitaemia after vaccination (primary outcome) and the incidence of various solicited and unsolicited adverse events (secondary outcome). The quality of the included RCTs using the Cochrane ROB 1 tool and the quality of evidence using the GRADE system were evaluated. We pooled dichotomous data using the risk ratio (RR) for development of parasitemia in vaccinees relative to controls as a measure of vaccine efficacy (VE), including the corresponding confidence interval (CI). This study was registered with PROSPERO (CRD42022308057). RESULTS We included 19 RCTs. Pooled RR favoured PfSPZ Vaccine (RR: 0.65 with 95% CI [0.53, 0.79], P = 0.0001) and PfSPZ-table (RR: 0.42 with 95% CI [0.27, 0.67], P = 0.0002) for preventing parasitaemia, relative to normal saline placebo. Pooled RR showed no difference between PfSPZ Vaccine and the control in the occurrence of any solicited adverse event (RR: 1.00 with 95% CI [0.82, 1.23], P = 0.98), any local solicited adverse events (RR: 0.73 with 95% CI [0.49, 1.08], P = 0.11), any systemic solicited adverse events (RR: 0.94 with 95% CI [0.75, 1.17], P = 0.58), and any unsolicited adverse event (RR: 0.93 with 95% CI [0.78, 1.10], P = 0.37). CONCLUSION PfSPZ and PfSPZ-CVacs showed comparable efficacy. Therefore, they can introduce a promising strategy for malaria prophylaxis, but more large-scale field trials are required to sustain efficacy and yield clinically applicable findings.
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Affiliation(s)
| | | | | | - Helmy Badr
- Faculty of Medicine, Tanta University, Tanta, Egypt
| | | | | | - Basel Abdelazeem
- Department of Cardiology, West Virginia University, Morgantown, WV, USA
| | | | - Mohamed Abouzid
- Department of Physical Pharmacy and Pharmacokinetics, Poznan University of Medical Sciences, Rokietnicka 3, 60-806, Poznan, Poland.
- Doctoral School, Poznan University of Medical Sciences, Poznan, Poland.
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3
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Ventocilla JA, Tapia LL, Ponce R, Franco A, Leelawong M, Aguiar JC, Baldeviano GC, Wilder BK. Evaluation of naturally acquired immune responses against novel pre-erythrocytic Plasmodium vivax proteins in a low endemic malaria population located in the Peruvian Amazon Basin. Malar J 2024; 23:163. [PMID: 38783317 PMCID: PMC11118720 DOI: 10.1186/s12936-024-04978-z] [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: 12/13/2023] [Accepted: 05/09/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Plasmodium vivax represents the most geographically widespread human malaria parasite affecting civilian and military populations in endemic areas. Targeting the pre-erythrocytic (PE) stage of the parasite life cycle is especially appealing for developing P. vivax vaccines as it would prevent disease and transmission. Here, naturally acquired immunity to a panel of P. vivax PE antigens was explored, which may facilitate vaccine development and lead to a better understanding of naturally acquired PE immunity. METHODS Twelve P. vivax PE antigens orthologous to a panel of P. falciparum antigens previously identified as highly immunogenic in protected subjects after immunization with radiation attenuated sporozoites (RAS) were used for evaluation of humoral and cellular immunity by ELISA and IFN-γ ELISpot. Samples from P. vivax infected individuals (n = 76) from a low endemic malaria region in the Peruvian Amazon Basin were used. RESULTS In those clinical samples, all PE antigens evaluated showed positive IgG antibody reactivity with a variable prevalence of 58-99% in recently P. vivax diagnosed patients. The magnitude of the IgG antibody response against PE antigens was lower compared with blood stage antigens MSP1 and DBP-II, although antibody levels persisted better for PE antigens (average decrease of 6% for PE antigens and 43% for MSP1, p < 0.05). Higher IgG antibodies was associated with one or more previous malaria episodes only for blood stage antigens (p < 0.001). High IgG responders across PE and blood stage antigens showed significantly lower parasitaemia compared to low IgG responders (median 1,921 vs 4,663 par/µl, p < 0.05). In a subgroup of volunteers (n = 17),positive IFN-γ T cell response by ELISPOT was observed in 35% vs 9-35% against blood stage MSP1 and PE antigens, respectively, but no correlation with IgG responses. CONCLUSIONS These results demonstrate clear humoral and T cell responses against P. vivax PE antigens in individuals naturally infected with P. vivax. These data identify novel attractive PE antigens suitable for use in the potential development and selection of new malaria vaccine candidates which can be used as a part of malaria prevention strategies in civilian and military populations living in P. vivax endemic areas.
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Affiliation(s)
- Julio A Ventocilla
- Vysnova Partners Inc., Bethesda, USA
- Universidad Peruana Cayetano Heredia, Lima, Peru
| | - L Lorena Tapia
- U.S. Naval Medical Research Unit South, Lima-Peru (NAMRU SOUTH), Bellavista, Peru
| | | | | | - Mindy Leelawong
- U.S. Naval Medical Research Unit South, Lima-Peru (NAMRU SOUTH), Bellavista, Peru
- NYC Department of Health and Mental Hygiene, Long Island City, USA
| | | | - G Christian Baldeviano
- U.S. Naval Medical Research Unit South, Lima-Peru (NAMRU SOUTH), Bellavista, Peru
- Bluebird Bio, Inc, Somerville, USA
| | - Brandon K Wilder
- U.S. Naval Medical Research Unit South, Lima-Peru (NAMRU SOUTH), Bellavista, Peru.
- Oregon Health & Science University, Portland, USA.
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4
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van Dorst MMAR, Pyuza JJ, Nkurunungi G, Kullaya VI, Smits HH, Hogendoorn PCW, Wammes LJ, Everts B, Elliott AM, Jochems SP, Yazdanbakhsh M. Immunological factors linked to geographical variation in vaccine responses. Nat Rev Immunol 2024; 24:250-263. [PMID: 37770632 DOI: 10.1038/s41577-023-00941-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2023] [Indexed: 09/30/2023]
Abstract
Vaccination is one of medicine's greatest achievements; however, its full potential is hampered by considerable variation in efficacy across populations and geographical regions. For example, attenuated malaria vaccines in high-income countries confer almost 100% protection, whereas in low-income regions these same vaccines achieve only 20-50% protection. This trend is also observed for other vaccines, such as bacillus Calmette-Guérin (BCG), rotavirus and yellow fever vaccines, in terms of either immunogenicity or efficacy. Multiple environmental factors affect vaccine responses, including pathogen exposure, microbiota composition and dietary nutrients. However, there has been variable success with interventions that target these individual factors, highlighting the need for a better understanding of their downstream immunological mechanisms to develop new ways of modulating vaccine responses. Here, we review the immunological factors that underlie geographical variation in vaccine responses. Through the identification of causal pathways that link environmental influences to vaccine responsiveness, it might become possible to devise modulatory compounds that can complement vaccines for better outcomes in regions where they are needed most.
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Affiliation(s)
- Marloes M A R van Dorst
- Department of Parasitology, Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | - Jeremia J Pyuza
- Department of Parasitology, Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
- Department of Pathology, Kilimanjaro Christian Medical Centre, Moshi, Tanzania
| | - Gyaviira Nkurunungi
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe, Uganda
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Vesla I Kullaya
- Kilimanjaro Clinical Research Institute, Kilimanjaro Christian Medical Centre, Moshi, Tanzania
| | - Hermelijn H Smits
- Department of Parasitology, Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | | | - Linda J Wammes
- Department of Medical Microbiology, Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | - Bart Everts
- Department of Parasitology, Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | - Alison M Elliott
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe, Uganda
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Simon P Jochems
- Department of Parasitology, Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | - Maria Yazdanbakhsh
- Department of Parasitology, Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands.
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Scheiner M, Burda PC, Ingmundson A. Moving on: How malaria parasites exit the liver. Mol Microbiol 2024; 121:328-340. [PMID: 37602900 DOI: 10.1111/mmi.15141] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/22/2023]
Abstract
An essential step in the life cycle of malaria parasites is their egress from hepatocytes, which enables the transition from the asymptomatic liver stage to the pathogenic blood stage of infection. To exit the liver, Plasmodium parasites first disrupt the parasitophorous vacuole membrane that surrounds them during their intracellular replication. Subsequently, parasite-filled structures called merosomes emerge from the infected cell. Shrouded by host plasma membrane, like in a Trojan horse, parasites enter the vasculature undetected by the host immune system and travel to the lung where merosomes rupture, parasites are released, and the blood infection stage begins. This complex, multi-step process must be carefully orchestrated by the parasite and requires extensive manipulation of the infected host cell. This review aims to outline the known signaling pathways that trigger exit, highlight Plasmodium proteins that contribute to the release of liver-stage merozoites, and summarize the accompanying changes to the hepatic host cell.
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Affiliation(s)
- Mattea Scheiner
- Molecular Parasitology, Humboldt University Berlin, Berlin, Germany
| | - Paul-Christian Burda
- Centre for Structural Systems Biology, Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- University of Hamburg, Hamburg, Germany
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6
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Rathay V, Fürle K, Kiehl V, Ulmer A, Lanzer M, Thomson-Luque R. IgG Subclass Switch in Volunteers Repeatedly Immunized with the Full-Length Plasmodium falciparum Merozoite Surface Protein 1 (MSP1). Vaccines (Basel) 2024; 12:208. [PMID: 38400191 PMCID: PMC10893298 DOI: 10.3390/vaccines12020208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 02/11/2024] [Accepted: 02/13/2024] [Indexed: 02/25/2024] Open
Abstract
Vaccines are highly effective tools against infectious diseases and are also considered necessary in the fight against malaria. Vaccine-induced immunity is frequently mediated by antibodies. We have recently conducted a first-in-human clinical trial featuring SumayaVac-1, a malaria vaccine based on the recombinant, full-length merozoite surface protein 1 (MSP1FL) formulated with GLA-SE as an adjuvant. Vaccination with MSP1FL was safe and elicited sustainable IgG antibody titers that exceeded those observed in semi-immune populations from Africa. Moreover, IgG antibodies stimulated various Fc-mediated effector mechanisms associated with protection against malaria. However, these functionalities gradually waned. Here, we show that the initial two doses of SumayaVac-1 primarily induced the cytophilic subclasses IgG1 and IgG3. Unexpectedly, a shift in the IgG subclass composition occurred following the third and fourth vaccinations. Specifically, there was a progressive transition to IgG4 antibodies, which displayed a reduced capacity to engage in Fc-mediated effector functions and also exhibited increased avidity. In summary, our analysis of antibody responses to MSP1FL vaccination unveils a temporal shift towards noninflammatory IgG4 antibodies. These findings underscore the importance of considering the impact of IgG subclass composition on vaccine-induced immunity, particularly concerning Fc-mediated effector functions. This knowledge is pivotal in guiding the design of optimal vaccination strategies against malaria, informing decision making for future endeavors in this critical field.
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Affiliation(s)
- Veronika Rathay
- Parasitology, Centre for Infectious Diseases, University Hospital Heidelberg, Medical Faculty, Heidelberg University, 69120 Heidelberg, Germany
| | - Kristin Fürle
- Parasitology, Centre for Infectious Diseases, University Hospital Heidelberg, Medical Faculty, Heidelberg University, 69120 Heidelberg, Germany
| | - Viktoria Kiehl
- Parasitology, Centre for Infectious Diseases, University Hospital Heidelberg, Medical Faculty, Heidelberg University, 69120 Heidelberg, Germany
| | - Anne Ulmer
- Parasitology, Centre for Infectious Diseases, University Hospital Heidelberg, Medical Faculty, Heidelberg University, 69120 Heidelberg, Germany
| | - Michael Lanzer
- Parasitology, Centre for Infectious Diseases, University Hospital Heidelberg, Medical Faculty, Heidelberg University, 69120 Heidelberg, Germany
| | - Richard Thomson-Luque
- Parasitology, Centre for Infectious Diseases, University Hospital Heidelberg, Medical Faculty, Heidelberg University, 69120 Heidelberg, Germany
- Sumaya-Biotech GmbH & Co. KG, 69115 Heidelberg, Germany
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7
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Watson FN, Shears MJ, Kalata AC, Duncombe CJ, Seilie AM, Chavtur C, Conrad E, Cruz Talavera I, Raappana A, Sather DN, Chakravarty S, Sim BKL, Hoffman SL, Tsuji M, Murphy SC. Ultra-low volume intradermal administration of radiation-attenuated sporozoites with the glycolipid adjuvant 7DW8-5 completely protects mice against malaria. Sci Rep 2024; 14:2881. [PMID: 38311678 PMCID: PMC10838921 DOI: 10.1038/s41598-024-53118-9] [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: 01/19/2023] [Accepted: 01/28/2024] [Indexed: 02/06/2024] Open
Abstract
Radiation-attenuated sporozoite (RAS) vaccines can completely prevent blood stage Plasmodium infection by inducing liver-resident memory CD8+ T cells to target parasites in the liver. Such T cells can be induced by 'Prime-and-trap' vaccination, which here combines DNA priming against the P. yoelii circumsporozoite protein (CSP) with a subsequent intravenous (IV) dose of liver-homing RAS to "trap" the activated and expanding T cells in the liver. Prime-and-trap confers durable protection in mice, and efforts are underway to translate this vaccine strategy to the clinic. However, it is unclear whether the RAS trapping dose must be strictly administered by the IV route. Here we show that intradermal (ID) RAS administration can be as effective as IV administration if RAS are co-administrated with the glycolipid adjuvant 7DW8-5 in an ultra-low inoculation volume. In mice, the co-administration of RAS and 7DW8-5 in ultra-low ID volumes (2.5 µL) was completely protective and dose sparing compared to standard volumes (10-50 µL) and induced protective levels of CSP-specific CD8+ T cells in the liver. Our finding that adjuvants and ultra-low volumes are required for ID RAS efficacy may explain why prior reports about higher volumes of unadjuvanted ID RAS proved less effective than IV RAS. The ID route may offer significant translational advantages over the IV route and could improve sporozoite vaccine development.
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Affiliation(s)
- Felicia N Watson
- Graduate Program in Pathobiology, Department of Global Health, University of Washington, Seattle, WA, 98109, USA
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
- Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, 98109, USA
| | - Melanie J Shears
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
- Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, 98109, USA
| | - Anya C Kalata
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
- Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, 98109, USA
| | - Caroline J Duncombe
- Graduate Program in Pathobiology, Department of Global Health, University of Washington, Seattle, WA, 98109, USA
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
- Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, 98109, USA
| | - A Mariko Seilie
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
- Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, 98109, USA
| | - Chris Chavtur
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
- Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, 98109, USA
| | - Ethan Conrad
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
- Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, 98109, USA
| | - Irene Cruz Talavera
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
- Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, 98109, USA
| | - Andrew Raappana
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, 98109, USA
| | - D Noah Sather
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, 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
| | - Stephen L Hoffman
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Moriya Tsuji
- Aaron Diamond AIDS Research Center, Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Sean C Murphy
- Graduate Program in Pathobiology, Department of Global Health, University of Washington, Seattle, WA, 98109, USA.
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA.
- Center for Emerging and Re-emerging Infectious Diseases (CERID), University of Washington, Seattle, WA, 98109, USA.
- Department of Microbiology, University of Washington, Seattle, WA, 98109, USA.
- Washington National Primate Research Center, University of Washington, Seattle, WA, 98109, USA.
- Department of Laboratories, Seattle Children's Hospital, Seattle, WA, 98105, USA.
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Jongo S, Church LP, Milando F, Qassim M, Schindler T, Rashid M, Tumbo A, Nyaulingo G, Bakari BM, Athuman Mbaga T, Mohamed L, Kassimu K, Simon BS, Mpina M, Zaidi I, Duffy PE, Swanson PA, Seder R, Herman JD, Mendu M, Zur Y, Alter G, KC N, Riyahi P, Abebe Y, Murshedkar T, James ER, Billingsley PF, Sim BKL, Richie TL, Daubenberger C, Abdulla S, Hoffman SL. Safety and protective efficacy of PfSPZ Vaccine administered to HIV-negative and -positive Tanzanian adults. J Clin Invest 2024; 134:e169060. [PMID: 38194272 PMCID: PMC10940097 DOI: 10.1172/jci169060] [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: 01/25/2023] [Accepted: 12/20/2023] [Indexed: 01/10/2024] Open
Abstract
BACKGROUNDSanaria PfSPZ Vaccine, composed of attenuated Plasmodium falciparum (Pf) sporozoites (SPZ), protects against malaria. We conducted this clinical trial to assess the safety and efficacy of PfSPZ Vaccine in HIV-positive (HIV+) individuals, since the HIV-infection status of participants in mass vaccination programs may be unknown.METHODSThis randomized, double-blind, placebo-controlled trial enrolled 18- to 45-year-old HIV-negative (HIV-) and well-controlled HIV+ Tanzanians (HIV viral load <40 copies/mL, CD4 counts >500 cells/μL). Participants received 5 doses of PfSPZ Vaccine or normal saline (NS) over 28 days, followed by controlled human malaria infection (CHMI) 3 weeks later.RESULTSThere were no solicited adverse events in the 9 HIV- and 12 HIV+ participants. After CHMI, 6 of 6 NS controls, 1 of 5 HIV- vaccinees, and 4 of 4 HIV+ vaccinees were Pf positive by quantitative PCR (qPCR). After immunization, anti-Pf circumsporozoite protein (anti-PfCSP) (isotype and IgG subclass) and anti-PfSPZ antibodies, anti-PfSPZ CD4+ T cell responses, and Vδ2+ γδ CD3+ T cells were nonsignificantly higher in HIV- than in HIV+ vaccinees. Sera from HIV- vaccinees had significantly higher inhibition of PfSPZ invasion of hepatocytes in vitro and antibody-dependent complement deposition (ADCD) and Fcγ3B binding by anti-PfCSP and ADCD by anti-cell-traversal protein for ookinetes and SPZ (anti-PfCelTOS) antibodies.CONCLUSIONSPfSPZ Vaccine was safe and well tolerated in HIV+ vaccinees, but not protective. Vaccine efficacy was 80% in HIV- vaccinees (P = 0.012), whose sera had significantly higher inhibition of PfSPZ invasion of hepatocytes and enrichment of multifunctional PfCSP antibodies. A more potent PfSPZ vaccine or regimen is needed to protect those living with HIV against Pf infection in Africa.TRIAL REGISTRATIONClinicalTrials.gov NCT03420053.FUNDINGEquatorial Guinea Malaria Vaccine Initiative (EGMVI), made up of the Government of Equatorial Guinea Ministries of Mines and Hydrocarbons, and Health and Social Welfare, Marathon Equatorial Guinea Production Limited, Noble Energy, Atlantic Methanol Production Company, and EG LNG; Swiss government, through ESKAS scholarship grant no. 2016.0056; Intramural Research Program of the National Institute of Allergy and Infectious Diseases, NIH; NIH grant 1U01AI155354-01.
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Affiliation(s)
- Said Jongo
- Ifakara Health Institute (IHI), Bagamoyo, Tanzania
| | | | | | | | - Tobias Schindler
- Swiss Tropical Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Anneth Tumbo
- Ifakara Health Institute (IHI), Bagamoyo, Tanzania
- Swiss Tropical Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | | | | | | | | | | | - Maxmillian Mpina
- Ifakara Health Institute (IHI), Bagamoyo, Tanzania
- Swiss Tropical Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Irfan Zaidi
- Laboratory of Malaria Immunology and Vaccinology and
| | | | | | - Robert Seder
- Vaccine Research Center, NIH, Bethesda, Maryland, USA
| | - Jonathan D. Herman
- Division of Infectious Disease, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- The Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, USA
| | - Maanasa Mendu
- The Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, USA
| | - Yonatan Zur
- The Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, USA
| | - Galit Alter
- The Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, USA
| | - Natasha KC
- Sanaria Inc., Rockville, Maryland, USA
- Protein Potential LLC, Rockville, Maryland, USA
| | | | | | | | | | | | - B. Kim Lee Sim
- Sanaria Inc., Rockville, Maryland, USA
- Protein Potential LLC, Rockville, Maryland, USA
| | | | - Claudia Daubenberger
- Swiss Tropical Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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9
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Tsoumani ME, Voyiatzaki C, Efstathiou A. Malaria Vaccines: From the Past towards the mRNA Vaccine Era. Vaccines (Basel) 2023; 11:1452. [PMID: 37766129 PMCID: PMC10536368 DOI: 10.3390/vaccines11091452] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 08/29/2023] [Accepted: 09/01/2023] [Indexed: 09/29/2023] Open
Abstract
Plasmodium spp. is the etiological agent of malaria, a life-threatening parasitic disease transmitted by infected mosquitoes. Malaria remains a major global health challenge, particularly in endemic regions. Over the years, various vaccine candidates targeting different stages of Plasmodium parasite life-cycle have been explored, including subunit vaccines, vectored vaccines, and whole organism vaccines with Mosquirix, a vaccine based on a recombinant protein, as the only currently approved vaccine for Plasmodium falciparum malaria. Despite the aforementioned notable progress, challenges such as antigenic diversity, limited efficacy, resistant parasites escaping protective immunity and the need for multiple doses have hindered the development of a highly efficacious malaria vaccine. The recent success of mRNA-based vaccines against SARS-CoV-2 has sparked renewed interest in mRNA vaccine platforms. The unique mRNA vaccine features, including their potential for rapid development, scalability, and flexibility in antigen design, make them a promising avenue for malaria vaccine development. This review provides an overview of the malaria vaccines' evolution from the past towards the mRNA vaccine era and highlights their advantages in overcoming the limitations of previous malaria vaccine candidates.
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Affiliation(s)
- Maria E. Tsoumani
- Department of Biomedical Sciences, University of West Attica, 12243 Aigaleo, Greece; (M.E.T.); (C.V.)
| | - Chrysa Voyiatzaki
- Department of Biomedical Sciences, University of West Attica, 12243 Aigaleo, Greece; (M.E.T.); (C.V.)
| | - Antonia Efstathiou
- Department of Biomedical Sciences, University of West Attica, 12243 Aigaleo, Greece; (M.E.T.); (C.V.)
- Immunology of Infection Group, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece
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10
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Shears MJ, Watson FN, Stone BC, Cruz Talavera I, Parthiban C, Matsubara J, Kc N, Sim BKL, Hoffman SL, Murphy SC. Preliminary studies on the immunogenicity of a prime-and-trap malaria vaccine in nonhuman primates. Vaccine 2023; 41:5494-5498. [PMID: 37563050 PMCID: PMC10528330 DOI: 10.1016/j.vaccine.2023.07.067] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 07/21/2023] [Accepted: 07/28/2023] [Indexed: 08/12/2023]
Abstract
Development of next-generation vaccines against Plasmodium falciparum (Pf) is a priority. Many malaria vaccines target the pre-erythrocytic sporozoite (SPZ) and liver stages. These include subunit vaccines based on the Pf circumsporozoite protein (CSP) and attenuated PfSPZ vaccines. However, these strategies require 3-4 doses and have not achieved optimal efficacy against field-transmitted malaria. Prime-and-trap is a recently developed two-step heterologous vaccine strategy that combines priming with DNA encoding CSP followed by a single dose of attenuated SPZ. This strategy aims to induce CD8+ T cells that can eliminate parasites in the liver. Prior data has demonstrated that prime-and-trap with P. yoelii CSP and PySPZ was immunogenic and protective in mice. Here we report preliminary data on the immunogenicity of PfCSP prime and PfSPZ trap vaccine in rhesus macaques. This vaccine induced PfCSP-specific antibodies and T cell responses in all animals. However, response magnitude differed between individuals, suggesting further study is required.
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Affiliation(s)
- Melanie J Shears
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, United States.
| | - Felicia N Watson
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, United States
| | - Brad C Stone
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, United States
| | - Irene Cruz Talavera
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, United States
| | - Chaitra Parthiban
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, United States
| | - Jokichi Matsubara
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, United States
| | - Natasha Kc
- Sanaria Inc., Rockville, MD, United States
| | | | | | - Sean C Murphy
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, United States; Department of Microbiology, University of Washington, Seattle, WA, United States; Washington National Primate Research Center, University of Washington, Seattle, WA, United States.
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11
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Watson FN, Shears MJ, Kalata AC, Duncombe CJ, Seilie AM, Chavtur C, Conrad E, Talavera IC, Raappana A, Sather DN, Chakravarty S, Sim BKL, Hoffman SL, Tsuji M, Murphy SC. Ultra-low volume intradermal administration of radiation-attenuated sporozoites with the glycolipid adjuvant 7DW8-5 completely protects mice against malaria. RESEARCH SQUARE 2023:rs.3.rs-3243319. [PMID: 37609210 PMCID: PMC10441511 DOI: 10.21203/rs.3.rs-3243319/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Malaria is caused by Plasmodium parasites and was responsible for over 247 million infections and 619,000 deaths in 2021. Radiation-attenuated sporozoite (RAS) vaccines can completely prevent blood stage infection by inducing protective liver-resident memory CD8+ T cells. Such T cells can be induced by 'prime-and-trap' vaccination, which here combines DNA priming against the P. yoelii circumsporozoite protein (CSP) with a subsequent intravenous (IV) dose of liver-homing RAS to "trap" the activated and expanding T cells in the liver. Prime-and-trap confers durable protection in mice, and efforts are underway to translate this vaccine strategy to the clinic. However, it is unclear whether the RAS trapping dose must be strictly administered by the IV route. Here we show that intradermal (ID) RAS administration can be as effective as IV administration if RAS are co-administrated with the glycolipid adjuvant 7DW8-5 in an ultra-low inoculation volume. In mice, the co-administration of RAS and 7DW8-5 in ultra-low ID volumes (2.5 μL) was completely protective and dose sparing compared to standard volumes (10-50 μL) and induced protective levels of CSP-specific CD8+ T cells in the liver. Our finding that adjuvants and ultra-low volumes are required for ID RAS efficacy may explain why prior reports about higher volumes of unadjuvanted ID RAS proved less effective. The ID route may offer significant translational advantages over the IV route and could improve sporozoite vaccine development.
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12
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Ciubotariu II, Monroe A, Williams NA, Ogoma SB, Okumu F. Ifakara MasterClasses: lessons from leading experts on the battle against malaria. Trends Parasitol 2023; 39:607-614. [PMID: 37331883 DOI: 10.1016/j.pt.2023.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 05/24/2023] [Indexed: 06/20/2023]
Affiliation(s)
- Ilinca I Ciubotariu
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
| | - April Monroe
- Johns Hopkins Center for Communication Programs, Baltimore, MD, USA; Ifakara Health Institute, Ifakara, Tanzania.
| | - Nana Aba Williams
- MESA Alliance, Barcelona Institute for Global Health (ISGlobal), Barcelona, Spain; Barcelona Institute for Global Health (ISGlobal), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
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13
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El-Moamly AA, El-Sweify MA. Malaria vaccines: the 60-year journey of hope and final success-lessons learned and future prospects. Trop Med Health 2023; 51:29. [PMID: 37198702 DOI: 10.1186/s41182-023-00516-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 04/18/2023] [Indexed: 05/19/2023] Open
Abstract
BACKGROUND The world has made great strides towards beating malaria, although about half of the world population is still exposed to the risk of contracting malaria. Developing an effective malaria vaccine was a huge challenge for medical science. In 2021 the World Health Organization (WHO) approved the first malaria vaccine, RTS,S/AS01 vaccine (Mosquirix™), for widespread use. This review highlights the history of development, and the different approaches and types of malaria vaccines, and the literature to date. It covers the developmental stages of RTS,S/AS01 and recommends steps for its deployment. The review explores other potential vaccine candidates and their status, and suggests options for their further development. It also recommends future roles for vaccines in eradicating malaria. Questions remain on how RTS,S vaccine will work in widespread use and how it can best be utilized to benefit vulnerable communities. CONCLUSION Malaria vaccines have been in development for almost 60 years. The RTS,S/AS01 vaccine has now been approved, but cannot be a stand-alone solution. Development should continue on promising candidates such as R21, PfSPZ and P. vivax vaccines. Multi-component vaccines may be a useful addition to other malaria control techniques in achieving eradication of malaria.
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Affiliation(s)
- Amal A El-Moamly
- Department of Medical Parasitology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
| | - Mohamed A El-Sweify
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
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14
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Martina CE, Crowe JE, Meiler J. Glycan masking in vaccine design: Targets, immunogens and applications. Front Immunol 2023; 14:1126034. [PMID: 37033915 PMCID: PMC10076883 DOI: 10.3389/fimmu.2023.1126034] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 02/28/2023] [Indexed: 04/11/2023] Open
Abstract
Glycan masking is a novel technique in reverse vaccinology in which sugar chains (glycans) are added on the surface of immunogen candidates to hide regions of low interest and thus focus the immune system on highly therapeutic epitopes. This shielding strategy is inspired by viruses such as influenza and HIV, which are able to escape the immune system by incorporating additional glycosylation and preventing the binding of therapeutic antibodies. Interestingly, the glycan masking technique is mainly used in vaccine design to fight the same viruses that naturally use glycans to evade the immune system. In this review we report the major successes obtained with the glycan masking technique in epitope-focused vaccine design. We focus on the choice of the target antigen, the strategy for immunogen design and the relevance of the carrier vector to induce a strong immune response. Moreover, we will elucidate the different applications that can be accomplished with glycan masking, such as shifting the immune response from hyper-variable epitopes to more conserved ones, focusing the response on known therapeutic epitopes, broadening the response to different viral strains/sub-types and altering the antigen immunogenicity to elicit higher or lower immune response, as desired.
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Affiliation(s)
- Cristina E. Martina
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
- Center for Structural Biology, Vanderbilt University, Nashville, TN, United States
| | - James E. Crowe
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Jens Meiler
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
- Center for Structural Biology, Vanderbilt University, Nashville, TN, United States
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig, Germany
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15
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Zanghi G, Patel H, Camargo N, Smith JL, Bae Y, Flannery EL, Chuenchob V, Fishbaugher ME, Mikolajczak SA, Roobsoong W, Sattabongkot J, Hayes K, Vaughan AM, Kappe SHI. Global gene expression of human malaria parasite liver stages throughout intrahepatocytic development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.05.522945. [PMID: 36711670 PMCID: PMC9881933 DOI: 10.1101/2023.01.05.522945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Plasmodium falciparum (Pf) is causing the greatest malaria burden, yet the liver stages (LS) of this most important parasite species have remained poorly studied. Here, we used a human liver-chimeric mouse model in combination with a novel fluorescent PfNF54 parasite line (PfNF54cspGFP) to isolate PfLS-infected hepatocytes and generate transcriptomes that cover the major LS developmental phases in human hepatocytes. RNA-seq analysis of early Pf LS trophozoites two days after infection, revealed a central role of translational regulation in the transformation of the extracellular invasive sporozoite into intracellular LS. The developmental time course gene expression analysis indicated that fatty acid biosynthesis, isoprenoid biosynthesis and iron metabolism are sustaining LS development along with amino acid metabolism and biosynthesis. Countering oxidative stress appears to play an important role during intrahepatic LS development. Furthermore, we observed expression of the variant PfEMP1 antigen-encoding var genes, and we confirmed expression of PfEMP1 protein during LS development. Transcriptome comparison of the late Pf liver stage schizonts with P. vivax (Pv) late liver stages revealed highly conserved gene expression profiles among orthologous genes. A notable difference however was the expression of genes regulating sexual stage commitment. While Pv schizonts expressed markers of sexual commitment, the Pf LS parasites were not sexually committed and showed expression of gametocytogenesis repression factors. Our results provide the first comprehensive gene expression profile of the human malaria parasite Pf LS isolated during in vivo intrahepatocytic development. This data will inform biological studies and the search for effective intervention strategies that can prevent infection.
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Affiliation(s)
- Gigliola Zanghi
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Hardik Patel
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Nelly Camargo
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Jenny L. Smith
- Research Scientific Computing, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Yeji Bae
- Research Scientific Computing, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Erika L. Flannery
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- Novartis Institute for Tropical Diseases, Emeryville, CA, United State
| | - Vorada Chuenchob
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- Novartis Institute for Tropical Diseases, Emeryville, CA, United State
| | - Matthew E. Fishbaugher
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- Novartis Institute for Tropical Diseases, Emeryville, CA, United State
| | - Sebastian A Mikolajczak
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- Novartis Institute for Tropical Diseases, Emeryville, CA, United State
| | - Wanlapa Roobsoong
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Kiera Hayes
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Ashley M. Vaughan
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- Department of Pediatrics, University of Washington
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Stefan H. I. Kappe
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- Department of Pediatrics, University of Washington
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
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16
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Chandley P, Ranjan R, Kumar S, Rohatgi S. Host-parasite interactions during Plasmodium infection: Implications for immunotherapies. Front Immunol 2023; 13:1091961. [PMID: 36685595 PMCID: PMC9845897 DOI: 10.3389/fimmu.2022.1091961] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 12/12/2022] [Indexed: 01/05/2023] Open
Abstract
Malaria is a global infectious disease that remains a leading cause of morbidity and mortality in the developing world. Multiple environmental and host and parasite factors govern the clinical outcomes of malaria. The host immune response against the Plasmodium parasite is heterogenous and stage-specific both in the human host and mosquito vector. The Plasmodium parasite virulence is predominantly associated with its ability to evade the host's immune response. Despite the availability of drug-based therapies, Plasmodium parasites can acquire drug resistance due to high antigenic variations and allelic polymorphisms. The lack of licensed vaccines against Plasmodium infection necessitates the development of effective, safe and successful therapeutics. To design an effective vaccine, it is important to study the immune evasion strategies and stage-specific Plasmodium proteins, which are targets of the host immune response. This review provides an overview of the host immune defense mechanisms and parasite immune evasion strategies during Plasmodium infection. Furthermore, we also summarize and discuss the current progress in various anti-malarial vaccine approaches, along with antibody-based therapy involving monoclonal antibodies, and research advancements in host-directed therapy, which can together open new avenues for developing novel immunotherapies against malaria infection and transmission.
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Affiliation(s)
- Pankaj Chandley
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
| | - Ravikant Ranjan
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
| | - Sudhir Kumar
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Soma Rohatgi
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India,*Correspondence: Soma Rohatgi,
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17
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Moita D, Maia TG, Duarte M, Andrade CM, Albuquerque IS, Dwivedi A, Silva JC, González-Céron L, Janse CJ, Mendes AM, Prudêncio M. A genetically modified Plasmodium berghei parasite as a surrogate for whole-sporozoite vaccination against P. vivax malaria. NPJ Vaccines 2022; 7:163. [PMID: 36526627 PMCID: PMC9755804 DOI: 10.1038/s41541-022-00585-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022] Open
Abstract
Two malaria parasite species, Plasmodium falciparum (Pf) and P. vivax (Pv) are responsible for most of the disease burden caused by malaria. Vaccine development against this disease has focused mainly on Pf. Whole-sporozoite (WSp) vaccination, targeting pre-erythrocytic (PE) parasite stages, is a promising strategy for immunization against malaria and several PfWSp-based vaccine candidates are currently undergoing clinical evaluation. In contrast, no WSp candidates have been developed for Pv, mainly due to constraints in the production of Pv sporozoites in the laboratory. Recently, we developed a novel approach for WSp vaccination against Pf based on the use of transgenic rodent P. berghei (Pb) sporozoites expressing immunogens of this human-infective parasite. We showed that this platform can be used to deliver PE Pf antigens, eliciting both targeted humoral responses and cross-species cellular immune responses against Pf. Here we explored this WSp platform for the delivery of Pv antigens. As the Pv circumsporozoite protein (CSP) is a leading vaccine candidate antigen, we generated a transgenic Pb parasite, PbviVac, that, in addition to its endogenous PbCSP, expresses PvCSP under the control of a strictly PE promoter. Immunofluorescence microscopy analyses confirmed that both the PbCSP and the PvCSP antigens are expressed in PbviVac sporozoites and liver stages and that PbviVac sporozoite infectivity of hepatic cells is similar to that of its wild-type Pb counterpart. Immunization of mice with PbviVac sporozoites elicits the production of anti-PvCSP antibodies that efficiently recognize and bind to Pv sporozoites. Our results warrant further development and evaluation of PbviVac as a surrogate for WSp vaccination against Pv malaria.
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Affiliation(s)
- Diana Moita
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Teresa G Maia
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Miguel Duarte
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Carolina M Andrade
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Inês S Albuquerque
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Ankit Dwivedi
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Joana C Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Lilia González-Céron
- Centro Regional de Investigación en Salud Pública, Instituto Nacional de Salud Pública, Tapachula, Chiapas, México
| | - Chris J Janse
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - António M Mendes
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Miguel Prudêncio
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal.
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18
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Duffy PE. Current approaches to malaria vaccines. Curr Opin Microbiol 2022; 70:102227. [PMID: 36343566 PMCID: PMC11127243 DOI: 10.1016/j.mib.2022.102227] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/27/2022] [Accepted: 10/04/2022] [Indexed: 11/06/2022]
Abstract
The complex Plasmodium life cycle offers different vaccine approaches with distinct parasitological and clinical effects. The approaches and their rationales were established decades ago: vaccines targeting pre-erythrocytic (sporozoite and liver-stage) parasites prevent infection, those to blood-stage parasites reduce disease, and those to sexual-stage parasites or mosquito vector reduce transmission and eliminate malaria through herd immunity. The pre-erythrocytic RTS,S vaccine (Mosquirix, GlaskoSmithKline (GSK)), recommended by WHO in 2021, reduces clinical malaria in children. Knowledge of parasite biology, host-parasite interactions, and immune mechanisms is informing new concepts to improve on RTS,S and to target other parasite stages. This review emphasizes vaccine approaches and candidates currently in the clinic or likely to enter clinical testing soon.
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Affiliation(s)
- Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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19
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Creation and preclinical evaluation of genetically attenuated malaria parasites arresting growth late in the liver. NPJ Vaccines 2022; 7:139. [PMCID: PMC9636417 DOI: 10.1038/s41541-022-00558-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022] Open
Abstract
AbstractWhole-sporozoite (WSp) malaria vaccines induce protective immune responses in animal malaria models and in humans. A recent clinical trial with a WSp vaccine comprising genetically attenuated parasites (GAP) which arrest growth early in the liver (PfSPZ-GA1), showed that GAPs can be safely administered to humans and immunogenicity is comparable to radiation-attenuated PfSPZ Vaccine. GAPs that arrest late in the liver stage (LA-GAP) have potential for increased potency as shown in rodent malaria models. Here we describe the generation of four putative P. falciparum LA-GAPs, generated by CRISPR/Cas9-mediated gene deletion. One out of four gene-deletion mutants produced sporozoites in sufficient numbers for further preclinical evaluation. This mutant, PfΔmei2, lacking the mei2-like RNA gene, showed late liver growth arrest in human liver-chimeric mice with human erythrocytes, absence of unwanted genetic alterations and sensitivity to antimalarial drugs. These features of PfΔmei2 make it a promising vaccine candidate, supporting further clinical evaluation. PfΔmei2 (GA2) has passed regulatory approval for safety and efficacy testing in humans based on the findings reported in this study.
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20
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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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21
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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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22
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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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23
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Schneider CG, Fey J, Zou X, Gerbasi V, Savransky T, Batt C, Bergmann-Leitner E, Angov E. Norovirus-VLPs expressing pre-erythrocytic malaria antigens induce functional immunity against sporozoite infection. Vaccine 2022; 40:4270-4280. [PMID: 35697572 DOI: 10.1016/j.vaccine.2022.05.076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/27/2022] [Accepted: 05/24/2022] [Indexed: 10/18/2022]
Abstract
Despite the development of prophylactic anti-malarial drugs and practices to prevent infection, malaria remains a health concern. Preclinical testing of novel malaria vaccine strategies achieved through rational antigen selection and novel particle-based delivery platforms is yielding encouraging results. One such platform, self-assembling virus-like particles (VLP) is safer than attenuated live viruses, and has been approved as a vaccination tool by the FDA. We explore the use of Norovirus sub-viral particles lacking the natural shell (S) domain forming the interior shell but that retain the protruding (P) structures of the native virus as a vaccine vector. Epitope selection and their surface display has the potential to focus antigen specific immune responses to crucial epitopes. Recombinant P-particles displaying epitopes from two malaria antigens, Plasmodium falciparum (Pf) CelTOS and Plasmodium falciparum (Pf) CSP, were evaluated for immunogenicity and their ability to confer protection in a murine challenge model. Immune responses induced in mice resulted either in sterile protection (displaying PfCelTOS epitopes) or in antibodies with functional activity against sporozoites (displaying PfCSP epitopes) in an in vitro liver-stage development assay (ILSDA). These results are encouraging and support further evaluation of this platform as a vaccine delivery system.
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Affiliation(s)
- Cosette G Schneider
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN 37831, USA.
| | - Julien Fey
- Agave BioSystems, Ithaca, NY 14850, USA.
| | - Xiaoyan Zou
- Naval Medical Research Center, Silver Spring, MD 20910, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20817, USA
| | - Vince Gerbasi
- Naval Medical Research Center, Silver Spring, MD 20910, USA.
| | - Tatyana Savransky
- Entomology Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; General Dynamics Information Technology, Falls Church, VA 22042, USA.
| | - Carl Batt
- College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA.
| | - Elke Bergmann-Leitner
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
| | - Evelina Angov
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
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24
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Kibwana E, Kapulu M, Bejon P. Controlled Human Malaria Infection Studies in Africa-Past, Present, and Future. Curr Top Microbiol Immunol 2022. [PMID: 35704094 PMCID: PMC7616462 DOI: 10.1007/82_2022_256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Controlled human infection studies have contributed significantly to the understanding of pathogeneses and treatment of infectious diseases. In malaria, deliberately infecting humans with malaria parasites was used as a treatment for neurosyphilis in the early 1920s. More recently, controlled human malaria infection (CHMI) has become a valuable, cost-effective tool to fast-track the development and evaluation of new anti-malarial drugs and/or vaccines. CHMI studies have also been used to define host/parasite interactions and immunological correlates of protection. CHMI involves infecting a small number of healthy volunteers with malaria parasites, monitoring their parasitemia and providing anti-malarial treatment when a set threshold is reached. In this review we discuss the introduction, development, and challenges of modern-day Plasmodium falciparum CHMI studies conducted in Africa, and the impact of naturally acquired immunity on infectivity and vaccine efficacy. CHMIs have shown to be an invaluable tool particularly in accelerating malaria vaccine research. Although there are limitations of CHMI studies for estimating public health impacts and for regulatory purposes, their strength lies in proof-of-concept efficacy data at an early stage of development, providing a faster way to select vaccines for further development and providing valuable insights in understanding the mechanisms of immunity to malarial infection.
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Affiliation(s)
- Elizabeth Kibwana
- Bioscience Department, KEMRI-Wellcome Trust Research Program, Kilifi, Kenya
| | - Melissa Kapulu
- Bioscience Department, KEMRI-Wellcome Trust Research Program, Kilifi, Kenya
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Program, Kilifi, Kenya.
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25
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Abstract
"The Primate Malarias" book has been a uniquely important resource for multiple generations of scientists, since its debut in 1971, and remains pertinent to the present day. Indeed, nonhuman primates (NHPs) have been instrumental for major breakthroughs in basic and pre-clinical research on malaria for over 50 years. Research involving NHPs have provided critical insights and data that have been essential for malaria research on many parasite species, drugs, vaccines, pathogenesis, and transmission, leading to improved clinical care and advancing research goals for malaria control, elimination, and eradication. Whilst most malaria scientists over the decades have been studying Plasmodium falciparum, with NHP infections, in clinical studies with humans, or using in vitro culture or rodent model systems, others have been dedicated to advancing research on Plasmodium vivax, as well as on phylogenetically related simian species, including Plasmodium cynomolgi, Plasmodium coatneyi, and Plasmodium knowlesi. In-depth study of these four phylogenetically related species over the years has spawned the design of NHP longitudinal infection strategies for gathering information about ongoing infections, which can be related to human infections. These Plasmodium-NHP infection model systems are reviewed here, with emphasis on modern systems biological approaches to studying longitudinal infections, pathogenesis, immunity, and vaccines. Recent discoveries capitalizing on NHP longitudinal infections include an advanced understanding of chronic infections, relapses, anaemia, and immune memory. With quickly emerging new technological advances, more in-depth research and mechanistic discoveries can be anticipated on these and additional critical topics, including hypnozoite biology, antigenic variation, gametocyte transmission, bone marrow dysfunction, and loss of uninfected RBCs. New strategies and insights published by the Malaria Host-Pathogen Interaction Center (MaHPIC) are recapped here along with a vision that stresses the importance of educating future experts well trained in utilizing NHP infection model systems for the pursuit of innovative, effective interventions against malaria.
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Affiliation(s)
- Mary R Galinski
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA.
- Emory Vaccine Center, Emory University, Atlanta, GA, USA.
- Emory National Primate Research Center (Yerkes National Primate Research Center), Emory University, Atlanta, GA, USA.
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26
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Efficacy, T cell activation and antibody responses in accelerated Plasmodium falciparum sporozoite chemoprophylaxis vaccine regimens. NPJ Vaccines 2022; 7:59. [PMID: 35641527 PMCID: PMC9156686 DOI: 10.1038/s41541-022-00473-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 03/18/2022] [Indexed: 11/08/2022] Open
Abstract
Repeated direct venous inoculation of Plasmodium falciparum sporozoites (PfSPZ) together with antimalarial chemoprophylaxis (PfSPZ-CVac) is the most potent way to induce sterile immunity against P. falciparum infection in malaria-naive volunteers. However, established schedules are complex and long. Here, we tested two accelerated three-dose schedules (28- and 10-day regimen) assessing efficacy by controlled human malaria infection (CHMI) against placebo, comparing vaccine-specific T cell and antibody responses by antigen-reactive T cell enrichment (ARTE) and protein microarray, respectively. Both regimens were similarly efficacious (67 and 63% vaccine efficacy) but different in the induction of vaccine-specific T cells and antibodies. The 10-day regimen resulted in higher numbers of antigen-specific CD4+ effector memory pro-inflammatory T cells and a broader antibody response compared with the 28-day regimen. Usually in nature, P. falciparum liver stage lasts about 6.5 days. The short vaccination-interval of the 10-day regimen prolongs the time of continuous exposure to liver-stage parasites, which may explain the stronger response. Besides dose and number of vaccinations, duration of liver-stage exposure is a factor to optimize PfSPZ-CVac immunogenicity.
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27
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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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28
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Mpina M, Stabler TC, Schindler T, Raso J, Deal A, Acuche Pupu L, Nyakarungu E, Del Carmen Ovono Davis M, Urbano V, Mtoro A, Hamad A, Lopez MSA, Pasialo B, Eyang MAO, Rivas MR, Falla CC, García GA, Momo JC, Chuquiyauri R, Saverino E, Preston Church LW, Kim Lee Sim B, Manguire B, Tanner M, Maas C, Abdulla S, Billingsley PF, Hoffman SL, Jongo S, Richie TL, Daubenberger CA. Diagnostic performance and comparison of ultrasensitive and conventional rapid diagnostic test, thick blood smear and quantitative PCR for detection of low-density Plasmodium falciparum infections during a controlled human malaria infection study in Equatorial Guinea. Malar J 2022; 21:99. [PMID: 35331251 PMCID: PMC8943516 DOI: 10.1186/s12936-022-04103-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/23/2022] [Indexed: 12/02/2022] Open
Abstract
Background Progress towards malaria elimination has stagnated, partly because infections persisting at low parasite densities comprise a large reservoir contributing to ongoing malaria transmission and are difficult to detect. This study compared the performance of an ultrasensitive rapid diagnostic test (uRDT) designed to detect low density infections to a conventional RDT (cRDT), expert microscopy using Giemsa-stained thick blood smears (TBS), and quantitative polymerase chain reaction (qPCR) during a controlled human malaria infection (CHMI) study conducted in malaria exposed adults (NCT03590340). Methods Blood samples were collected from healthy Equatoguineans aged 18–35 years beginning on day 8 after CHMI with 3.2 × 103 cryopreserved, infectious Plasmodium falciparum sporozoites (PfSPZ Challenge, strain NF54) administered by direct venous inoculation. qPCR (18s ribosomal DNA), uRDT (Alere™ Malaria Ag P.f.), cRDT [Carestart Malaria Pf/PAN (PfHRP2/pLDH)], and TBS were performed daily until the volunteer became TBS positive and treatment was administered. qPCR was the reference for the presence of Plasmodium falciparum parasites. Results 279 samples were collected from 24 participants; 123 were positive by qPCR. TBS detected 24/123 (19.5% sensitivity [95% CI 13.1–27.8%]), uRDT 21/123 (17.1% sensitivity [95% CI 11.1–25.1%]), cRDT 10/123 (8.1% sensitivity [95% CI 4.2–14.8%]); all were 100% specific and did not detect any positive samples not detected by qPCR. TBS and uRDT were more sensitive than cRDT (TBS vs. cRDT p = 0.015; uRDT vs. cRDT p = 0.053), detecting parasitaemias as low as 3.7 parasites/µL (p/µL) (TBS and uRDT) compared to 5.6 p/µL (cRDT) based on TBS density measurements. TBS, uRDT and cRDT did not detect any of the 70/123 samples positive by qPCR below 5.86 p/µL, the qPCR density corresponding to 3.7 p/µL by TBS. The median prepatent periods in days (ranges) were 14.5 (10–20), 18.0 (15–28), 18.0 (15–20) and 18.0 (16–24) for qPCR, TBS, uRDT and cRDT, respectively; qPCR detected parasitaemia significantly earlier (3.5 days) than the other tests. Conclusions TBS and uRDT had similar sensitivities, both were more sensitive than cRDT, and neither matched qPCR for detecting low density parasitaemia. uRDT could be considered an alternative to TBS in selected applications, such as CHMI or field diagnosis, where qualitative, dichotomous results for malaria infection might be sufficient. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04103-y.
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Affiliation(s)
- Maxmillian Mpina
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland. .,Ifakara Health Institute, Ifakara, Tanzania.
| | - Thomas C Stabler
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Tobias Schindler
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Jose Raso
- Medical Care Development International, Malabo, Equatorial Guinea.,Equatorial Guinea Ministry of Health and Social Welfare, Malabo, Equatorial Guinea
| | - Anna Deal
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | | | - Elizabeth Nyakarungu
- Ifakara Health Institute, Ifakara, Tanzania.,Medical Care Development International, Malabo, Equatorial Guinea
| | | | - Vicente Urbano
- Medical Care Development International, Malabo, Equatorial Guinea.,Equatorial Guinea Ministry of Health and Social Welfare, Malabo, Equatorial Guinea
| | - Ali Mtoro
- Ifakara Health Institute, Ifakara, Tanzania.,Medical Care Development International, Malabo, Equatorial Guinea
| | - Ali Hamad
- Ifakara Health Institute, Ifakara, Tanzania.,Medical Care Development International, Malabo, Equatorial Guinea
| | - Maria Silvia A Lopez
- Medical Care Development International, Malabo, Equatorial Guinea.,Equatorial Guinea Ministry of Health and Social Welfare, Malabo, Equatorial Guinea
| | - Beltran Pasialo
- Medical Care Development International, Malabo, Equatorial Guinea.,Equatorial Guinea Ministry of Health and Social Welfare, Malabo, Equatorial Guinea
| | - Marta Alene Owono Eyang
- Medical Care Development International, Malabo, Equatorial Guinea.,Equatorial Guinea Ministry of Health and Social Welfare, Malabo, Equatorial Guinea
| | - Matilde Riloha Rivas
- Equatorial Guinea Ministry of Health and Social Welfare, Malabo, Equatorial Guinea
| | | | | | - Juan Carlos Momo
- Medical Care Development International, Malabo, Equatorial Guinea.,Equatorial Guinea Ministry of Health and Social Welfare, Malabo, Equatorial Guinea
| | - Raul Chuquiyauri
- Medical Care Development International, Malabo, Equatorial Guinea.,Sanaria Inc., 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | | | | | - B Kim Lee Sim
- Sanaria Inc., 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | | | - Marcel Tanner
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Carl Maas
- Marathon EG production Ltd., Houston, USA
| | | | | | | | - Said Jongo
- Ifakara Health Institute, Ifakara, Tanzania.,Medical Care Development International, Malabo, Equatorial Guinea
| | - Thomas L Richie
- Sanaria Inc., 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Claudia A Daubenberger
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
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29
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Sissoko MS, Healy SA, Katile A, Zaidi I, Hu Z, Kamate B, Samake Y, Sissoko K, Mwakingwe-Omari A, Lane J, Imeru A, Mohan R, Thera I, Guindo CO, Dolo A, Niare K, Koïta F, Niangaly A, Rausch KM, Zeguime A, Guindo MA, Bah A, Abebe Y, James ER, Manoj A, Murshedkar T, Kc N, Sim BKL, Billingsley PF, Richie TL, Hoffman SL, Doumbo O, Duffy PE. Safety and efficacy of a three-dose regimen of Plasmodium falciparum sporozoite vaccine in adults during an intense malaria transmission season in Mali: a randomised, controlled phase 1 trial. THE LANCET. INFECTIOUS DISEASES 2022; 22:377-389. [PMID: 34801112 PMCID: PMC8981424 DOI: 10.1016/s1473-3099(21)00332-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/28/2021] [Accepted: 05/28/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND WHO recently approved a partially effective vaccine that reduces clinical malaria in children, but increased vaccine activity is required to pursue malaria elimination. A phase 1 clinical trial was done in Mali, west Africa, to assess the safety, immunogenicity, and protective efficacy of a three-dose regimen of Plasmodium falciparum sporozoite (PfSPZ) Vaccine (a metabolically active, non-replicating, whole malaria sporozoite vaccine) against homologous controlled human malaria infection (CHMI) and natural P falciparum infection. METHODS We recruited healthy non-pregnant adults aged 18-50 years in Donéguébougou, Mali, and surrounding villages (Banambani, Toubana, Torodo, Sirababougou, Zorokoro) for an open-label, dose-escalation pilot study and, thereafter, a randomised, double-blind, placebo-controlled main trial. Pilot study participants were enrolled on an as-available basis to one group of CHMI infectivity controls and three staggered vaccine groups receiving: one dose of 4·5 × 105, one dose of 9 × 105, or three doses of 1·8 × 106 PfSPZ via direct venous inoculation at approximately 8 week intervals, followed by homologous CHMI 5 weeks later with infectious PfSPZ by direct venous inoculation (PfSPZ Challenge). Main cohort participants were stratified by village and randomly assigned (1:1) to receive three doses of 1·8 × 106 PfSPZ or normal saline at 1, 13, and 19 week intervals using permuted block design by the study statistician. The primary outcome was safety and tolerability of at least one vaccine dose; the secondary outcome was vaccine efficacy against homologous PfSPZ CHMI (pilot study) or against naturally transmitted P falciparum infection (main study) measured by thick blood smear. Combined artesunate and amodiaquine was administered to eliminate pre-existing parasitaemia. Outcomes were analysed by modified intention to treat (mITT; including all participants who received at least one dose of investigational product; safety and vaccine efficacy) and per protocol (vaccine efficacy). This trial is registered with ClinicalTrials.gov, number NCT02627456. FINDINGS Between Dec 20, 2015, and April 30, 2016, we enrolled 56 participants into the pilot study (five received the 4·5 × 105 dose, five received 9 × 105, 30 received 1·8 × 106, 15 were CHMI controls, and one withdrew before vaccination) and 120 participants into the main study cohort with 60 participants assigned PfSPZ Vaccine and 60 placebo in the main study. Adverse events and laboratory abnormalities post-vaccination in all dosing groups were few, mainly mild, and did not differ significantly between vaccine groups (all p>0·05). Unexpected severe transaminitis occured in four participants: one participant in pilot phase that received 1·8 × 106 PfSPZ Vaccine, one participant in main phase that received 1·8 × 106 PfSPZ Vaccine, and two participants in the main phase placebo group. During PfSPZ CHMI, approximately 5 weeks after the third dose of 1·8 × 106 PfSPZ, none of 29 vaccinees and one of 15 controls became positive on thick blood smear; subsequent post-hoc PCR analysis for submicroscopic blood stage infections detected P falciparum parasites in none of the 29 vaccine recipients and eight of 15 controls during CHMI. In the main trial, 32 (58%) of 55 vaccine recipients and 42 (78%) of 54 controls became positive on thick blood smear during 24-week surveillance after vaccination. Vaccine efficacy (1-hazard ratio) was 0·51 per protocol (95% CI 0·20-0·70; log-rank p=0·0042) and 0·39 by mITT (0·04-0·62; p=0·033); vaccine efficacy (1-risk ratio) was 0·24 per-protocol (0·02-0·41; p=0·031) and 0·22 mITT (0·01-0·39; p=0·041). INTERPRETATION A three-dose regimen of PfSPZ Vaccine was safe, well tolerated, and conferred 51% vaccine efficacy against intense natural P falciparum transmission, similar to 52% vaccine efficacy reported for a five-dose regimen in a previous trial. FUNDING US National Institute of Allergy and Infectious Diseases, National Institutes of Health, Sanaria. TRANSLATION For the French translation of the abstract see Supplementary Materials section.
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Affiliation(s)
- Mahamadou S Sissoko
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Sara A Healy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Abdoulaye Katile
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Irfan Zaidi
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Zonghui Hu
- Biostatistical Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Bourama Kamate
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Yacouba Samake
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Kourane Sissoko
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Agnes Mwakingwe-Omari
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA; Center for Vaccine Research, GlaxoSmithKline, Rockville, MD, USA
| | - Jacquelyn Lane
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Alemush Imeru
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Rathy Mohan
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ismaila Thera
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Cheick Oumar Guindo
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Amagana Dolo
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Karamoko Niare
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Fanta Koïta
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Amadou Niangaly
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Kelly M Rausch
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Amatigue Zeguime
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Merepen A Guindo
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Aissatou Bah
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA; Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | | | | | | | - Natasha Kc
- Sanaria, Rockville, MD, USA; Protein Potential, Rockville, MD, USA
| | - B Kim Lee Sim
- Sanaria, Rockville, MD, USA; Protein Potential, Rockville, MD, USA
| | | | | | | | - Ogobara Doumbo
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Mali
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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Lipid Nanoparticle Delivery Systems to Enable mRNA-Based Therapeutics. Pharmaceutics 2022; 14:pharmaceutics14020398. [PMID: 35214130 PMCID: PMC8876479 DOI: 10.3390/pharmaceutics14020398] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/31/2022] [Accepted: 02/05/2022] [Indexed: 12/13/2022] Open
Abstract
The world raced to develop vaccines to protect against the rapid spread of SARS-CoV-2 infection upon the recognition of COVID-19 as a global pandemic. A broad spectrum of candidates was evaluated, with mRNA-based vaccines emerging as leaders due to how quickly they were available for emergency use while providing a high level of efficacy. As a modular technology, the mRNA-based vaccines benefitted from decades of advancements in both mRNA and delivery technology prior to the current global pandemic. The fundamental lessons of the utility of mRNA as a therapeutic were pioneered by Dr. Katalin Kariko and her colleagues, perhaps most notably in collaboration with Drew Weissman at University of Pennsylvania, and this foundational work paved the way for the development of the first ever mRNA-based therapeutic authorized for human use, COMIRNATY®. In this Special Issue of Pharmaceutics, we will be honoring Dr. Kariko for her great contributions to the mRNA technology to treat diseases with unmet needs. In this review article, we will focus on the delivery platform, the lipid nanoparticle (LNP) carrier, which allowed the potential of mRNA therapeutics to be realized. Similar to the mRNA technology, the development of LNP systems has been ongoing for decades before culminating in the success of the first clinically approved siRNA-LNP product, ONPATTRO®, a treatment for an otherwise fatal genetic disease called transthyretin amyloidosis. Lessons learned from the siRNA-LNP experience enabled the translation into the mRNA platform with the eventual authorization and approval of the mRNA-LNP vaccines against COVID-19. This marks the beginning of mRNA-LNP as a pharmaceutical option to treat genetic diseases.
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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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Lefebvre MN, Drewry LL, Pewe LL, Hancox LS, Reyes-Sandoval A, Harty JT. Cutting Edge: Subunit Booster Vaccination Confers Sterilizing Immunity against Liver-Stage Malaria in Mice Initially Primed with a Weight-Normalized Dose of Radiation-Attenuated Sporozoites. THE JOURNAL OF IMMUNOLOGY 2021; 207:2631-2635. [PMID: 34716185 DOI: 10.4049/jimmunol.2100818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 09/25/2021] [Indexed: 11/19/2022]
Abstract
Radiation-attenuated sporozoite (RAS) vaccination offers hope for global malaria control through induction of protective liver-stage-specific memory CD8 T cells. Effective RAS vaccination regimens exist; however, widespread implementation remains unfeasible. A key difficulty resides in the need to administer three or more doses i.v. to achieve sufficient immunity. Strategies to reduce the number of RAS doses are therefore desirable. Here we used mice to model human immune responses to a single, suboptimal weight-normalized RAS dose administered i.v. followed by subunit vaccination to amplify liver-stage-specific memory CD8 T cells. RAS+subunit prime-boost regimens increased the numbers of liver-stage-specific memory CD8 T cells to a level greater than is present after one RAS vaccination. Both i.v. and i.m. subunit vaccine delivery induced immunity in mice, and many vaccinated mice completely cleared liver infection. These findings are particularly relevant to human vaccine development because RAS+subunit prime-boost vaccination would reduce the logistical challenges of multiple RAS-only immunizations.
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Affiliation(s)
- Mitchell N Lefebvre
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.,Medical Scientist Training Program, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.,Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, IA, USA; and
| | - Lisa L Drewry
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Lecia L Pewe
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Lisa S Hancox
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | | | - John T Harty
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA; .,Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, IA, USA; and
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Chemoprophylaxis under sporozoites-lumefantrine (CPS-LMF) immunization induce protective immune responses against Plasmodium yoelii sporozoites infection in mice. 3 Biotech 2021; 11:465. [PMID: 34745816 DOI: 10.1007/s13205-021-03022-0] [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: 07/20/2021] [Accepted: 10/06/2021] [Indexed: 01/16/2023] Open
Abstract
Malaria represents one of the major life-threatening diseases that poses a huge socio-economic impact, worldwide. Chemoprophylaxis vaccination using a relatively low number of wild-type infectious sporozoites represents an attractive and effective vaccine strategy against malaria. However, the role of immune responses to pre-erythrocytic versus blood-stage parasites in protection against different antimalarial drugs remains unclear. Here, in the present study, we explored the immune responses against the repetitive inoculation of live Plasmodium yoelii (P. yoelii) sporozoites in an experimental Swiss mouse model under antimalarial drug lumefantrine chemoprophylaxis (CPS-LMF). We monitored the liver stage parasitic load, pro/anti-inflammatory cytokines expression, and erythrocytic stage patency, following repetitive cycles of sporozoites inoculations. It was found that repetitive sporozoites inoculation under CPS-LMF results in delayed blood-stage infection during the fourth sporozoites challenge, while sterile protection was produced in mice following the fifth cycle of sporozoites challenge. Intriguingly, we observed a significant up-regulation of pro-inflammatory cytokines (IFN-γ, TNF-α and IL-12) and iNOS response and down-regulation of anti-inflammatory cytokines (IL-4, IL-10 and TGF-β) in the liver HMNC (hepatic mononuclear cells) and spleen cells after 4th and 5th cycle of sporozoites challenge in the CPS-LMF mice. Meanwhile, we also noticed that the liver stage parasites load under CPS-LMF immunization has gradually reduced after 2nd, 3rd, 4th and 5th sporozoites challenge. Overall, our study suggests that chemoprophylaxis vaccination under LMF drug cover develops strong immune responses and confer superior long-lasting protection against P. yoelii sporozoites. Furthermore, this vaccination strategy can be used to study the protective and stage-specific immunity against new protective antigens. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13205-021-03022-0.
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Opi DH, Kurtovic L, Chan JA, Horton JL, Feng G, Beeson JG. Multi-functional antibody profiling for malaria vaccine development and evaluation. Expert Rev Vaccines 2021; 20:1257-1272. [PMID: 34530671 DOI: 10.1080/14760584.2021.1981864] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION A vaccine would greatly accelerate current global efforts toward malaria elimination. While a partially efficacious vaccine has been achieved for Plasmodium falciparum, a major bottleneck in developing highly efficacious vaccines is a lack of reliable correlates of protection, and the limited application of assays that quantify functional immune responses to evaluate and down-select vaccine candidates in pre-clinical studies and clinical trials. AREAS COVERED In this review, we describe the important role of antibodies in immunity against malaria and detail the nature and functional activities of antibodies against the malaria-causing parasite. We highlight the growing understanding of antibody effector functions against malaria and in vitro assays to measure these functional antibody responses. We discuss the application of these assays to quantify antibody functions in vaccine development and evaluation. EXPERT OPINION It is becoming increasingly clear that multiple antibody effector functions are involved in immunity to malaria. Therefore, we propose that evaluating vaccine candidates needs to move beyond individual assays or measuring IgG magnitude alone. Instead, vaccine evaluation should incorporate the full breadth of antibody response types and harness a wider range of assays measuring functional antibody responses. We propose a 3-tier approach to implementing assays to inform vaccine evaluation.
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Affiliation(s)
- D Herbert Opi
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Liriye Kurtovic
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Jo-Anne Chan
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Jessica L Horton
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Gaoqian Feng
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - James G Beeson
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia.,Department of Microbiology, Monash University, Clayton, Australia
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Hon C, Friesen J, Ingmundson A, Scheppan D, Hafalla JCR, Müller K, Matuschewski K. Conservation of S20 as an Ineffective and Disposable IFNγ-Inducing Determinant of Plasmodium Sporozoites Indicates Diversion of Cellular Immunity. Front Microbiol 2021; 12:703804. [PMID: 34421862 PMCID: PMC8377727 DOI: 10.3389/fmicb.2021.703804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/07/2021] [Indexed: 11/19/2022] Open
Abstract
Despite many decades of research to develop a malaria vaccine, only one vaccine candidate has been explored in pivotal phase III clinical trials. This candidate subunit vaccine consists of a portion of a single Plasmodium antigen, circumsporozoite protein (CSP). This antigen was initially identified in the murine malaria model and shown to contain an immunodominant and protective CD8+ T cell epitope specific to the H-2Kd (BALB/c)-restricted genetic background. A high-content screen for CD8+ epitopes in the H2Kb/Db (C57BL/6)-restricted genetic background, identified two distinct dominant epitopes. In this study, we present a characterization of one corresponding antigen, the Plasmodium sporozoite-specific protein S20. Plasmodium berghei S20 knockout sporozoites and liver stages developed normally in vitro and in vivo. This potent infectivity of s20(-) sporozoites permitted comparative analysis of knockout and wild-type parasites in cell-based vaccination. Protective immunity of irradiation-arrested s20(-) sporozoites in single, double and triple immunizations was similar to irradiated unaltered sporozoites in homologous challenge experiments. These findings demonstrate the presence of an immunogenic Plasmodium pre-erythrocytic determinant, which is not essential for eliciting protection. Although S20 is not needed for colonization of the mammalian host and for initiation of a blood infection, it is conserved amongst Plasmodium species. Malarial parasites express conserved, immunogenic proteins that are not required to establish infection but might play potential roles in diverting cellular immune responses.
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Affiliation(s)
- Calvin Hon
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
| | - Johannes Friesen
- Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany.,Medical Care Unit Labor 28 GmbH, Berlin, Germany
| | - Alyssa Ingmundson
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Diana Scheppan
- Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Julius C R Hafalla
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Katja Müller
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
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Sedegah M, Hollingdale MR, Ganeshan H, Belmonte M, Huang J, Belmonte A, Inoue S, Velasco R, Hickey B, Teneza-Mora N, Lumsden J, Reyes S, Banania JG, Reyes A, Guzman I, Richie TL, Epstein JE, Villasante E. IMRAS-Immunization with radiation-attenuated Plasmodium falciparum sporozoites by mosquito bite: Cellular immunity to sporozoites, CSP, AMA1, TRAP and CelTOS. PLoS One 2021; 16:e0256396. [PMID: 34415964 PMCID: PMC8378721 DOI: 10.1371/journal.pone.0256396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 07/21/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Immunization with radiation-attenuated sporozoites (RAS) by mosquito bites provides >90% sterile protection against Plasmodium falciparum malaria in humans. We conducted a clinical trial based on data from previous RAS clinical trials that suggested that 800-1200 infected bites should induce ~50% protective vaccine efficacy (VE) against controlled human malaria infection (CHMI) administered three weeks after the final immunization. Two cohorts were immunized separately. VE was 55% in Cohort 1 but 90% in Cohort 2, the cohort that received a higher first dose and a reduced (fractional) fifth dose. Immune responses were better boosted by the fractional fifth dose in Cohort 2 and suggested the importance of the fractional fifth dose for increased protection in Cohort 2 responses. Three protected subjects were later boosted and were protected suggesting that protection could be extended to at least 67 weeks. METHODS The ex vivo FluoroSpot assay was used to measure peripheral IFN-γ, IL2, and IFN-γ+IL2 responses to PfNF54 sporozoites and malaria antigens CSP, AMA1, TRAP, and CelTOS using pools of synthetic overlapping 15mer peptides spanning each antigen. RESULTS There was no correlation between IFN-γ, IL2, and IFN-γ+IL2 responses to sporozoites and protection, but fold-increases between post-4th and post-5th responses greater than 1.0 occurred mostly in protected subjects. IFN-γ and IL2 responses to TRAP, CelTOS and CSP occurred only in protected subjects. Peripheral IFN-γ, IL2, and IFN-γ+IL2 responses were short-lived and low by 27 weeks post-CHMI but were restored by boosting. CONCLUSIONS These studies highlight the importance of vaccine dose and schedule for vaccine efficacy, and suggest that CSP, TRAP, AMA1 and CelTOS may be targets of protective immunity. The correlation between fold-increases in responses and protection should be explored in other vaccine trials. TRIAL REGISTRATION ClinicalTrials.gov NCT01994525.
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Affiliation(s)
- Martha Sedegah
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Michael R. Hollingdale
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Harini Ganeshan
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Maria Belmonte
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Jun Huang
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Arnel Belmonte
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Sandra Inoue
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Rachel Velasco
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Bradley Hickey
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Nimfa Teneza-Mora
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Joanne Lumsden
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Sharina Reyes
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Jo Glenna Banania
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Anatalio Reyes
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Ivelese Guzman
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Thomas L. Richie
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Judith E. Epstein
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Eileen Villasante
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
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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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Roestenberg M, Walk J, van der Boor SC, Langenberg MCC, Hoogerwerf MA, Janse JJ, Manurung M, Yap XZ, García AF, Koopman JPR, Meij P, Wessels E, Teelen K, van Waardenburg YM, van de Vegte-Bolmer M, van Gemert GJ, Visser LG, van der Ven AJAM, de Mast Q, Natasha KC, Abebe Y, Murshedkar T, Billingsley PF, Richie TL, Sim BKL, Janse CJ, Hoffman SL, Khan SM, Sauerwein RW. A double-blind, placebo-controlled phase 1/2a trial of the genetically attenuated malaria vaccine PfSPZ-GA1. Sci Transl Med 2021; 12:12/544/eaaz5629. [PMID: 32434847 DOI: 10.1126/scitranslmed.aaz5629] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 04/22/2020] [Indexed: 11/02/2022]
Abstract
Immunization with attenuated Plasmodium sporozoites can induce protection against malaria infection, as shown by Plasmodium falciparum (Pf) sporozoites attenuated by radiation in multiple clinical trials. As alternative attenuation strategy with a more homogeneous population of Pf sporozoites (PfSPZ), genetically engineered Plasmodium berghei sporozoites (SPZ) lacking the genes b9 and slarp induced sterile protection against malaria in mice. Consequently, PfSPZ-GA1 Vaccine, a Pf identical double knockout (Pf∆b9∆slarp), was generated as a genetically attenuated malaria parasite vaccine and tested for safety, immunogenicity, and preliminary efficacy in malaria-naïve Dutch volunteers. Dose-escalation immunizations up to 9.0 × 105 PfSPZ of PfSPZ-GA1 Vaccine were well tolerated without breakthrough blood-stage infection. Subsequently, groups of volunteers were immunized three times by direct venous inoculation with cryopreserved PfSPZ-GA1 Vaccine (9.0 × 105 or 4.5 × 105 PfSPZ, N = 13 each), PfSPZ Vaccine (radiation-attenuated PfSPZ, 4.5 × 105 PfSPZ, N = 13), or normal saline placebo at 8-week intervals, followed by exposure to mosquito bite controlled human malaria infection (CHMI). After CHMI, 3 of 25 volunteers from both PfSPZ-GA1 groups were sterilely protected, and the remaining 17 of 22 showed a patency ≥9 days (median patency in controls, 7 days; range, 7 to 9). All volunteers in the PfSPZ Vaccine control group developed parasitemia (median patency, 9 days; range, 7 to 12). Immunized groups exhibited a significant, dose-related increase in anti-Pf circumsporozoite protein (CSP) antibodies and Pf-specific interferon-γ (IFN-γ)-producing T cells. Although no definite conclusion can be drawn on the potential strength of protective efficacy of PfSPZ-GA1 Vaccine, the favorable safety profile and induced immune responses by PfSPZ-GA1 Vaccine warrant further clinical evaluation.
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Affiliation(s)
- Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, Netherlands.,Department of Infectious Diseases, Leiden University Medical Center, 2333 ZA Leiden, Netherlands
| | - Jona Walk
- Radboudumc Center for Infectious Diseases, Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands.,Radboudumc Center for Infectious Diseases, Department of Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands
| | - Saskia C van der Boor
- Radboudumc Center for Infectious Diseases, Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands
| | - Marijke C C Langenberg
- Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, Netherlands
| | | | - Jacqueline J Janse
- Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, Netherlands
| | - Mikhael Manurung
- Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, Netherlands
| | - X Zen Yap
- Radboudumc Center for Infectious Diseases, Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands
| | - Amanda Fabra García
- Radboudumc Center for Infectious Diseases, Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands
| | - Jan Pieter R Koopman
- Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, Netherlands
| | - Pauline Meij
- Interdivisional GMP Facility, Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, 2333 ZA Leiden, Netherlands
| | - Els Wessels
- Department of Medical Microbiology, Leiden University Medical Center, 2333 ZA Leiden, Netherlands
| | - Karina Teelen
- Radboudumc Center for Infectious Diseases, Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands
| | - Youri M van Waardenburg
- Radboudumc Center for Infectious Diseases, Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands
| | - Marga van de Vegte-Bolmer
- Radboudumc Center for Infectious Diseases, Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands
| | - Geert Jan van Gemert
- Radboudumc Center for Infectious Diseases, Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands
| | - Leo G Visser
- Department of Infectious Diseases, Leiden University Medical Center, 2333 ZA Leiden, Netherlands
| | - André J A M van der Ven
- Radboudumc Center for Infectious Diseases, Department of Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands
| | - Quirijn de Mast
- Radboudumc Center for Infectious Diseases, Department of Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands
| | | | | | | | | | | | | | - Chris J Janse
- Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, Netherlands
| | | | - Shahid M Khan
- Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, Netherlands
| | - Robert W Sauerwein
- Radboudumc Center for Infectious Diseases, Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands.
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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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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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Clustering and Erratic Movement Patterns of Syringe-Injected versus Mosquito-Inoculated Malaria Sporozoites Underlie Decreased Infectivity. mSphere 2021; 6:6/2/e00218-21. [PMID: 33827910 PMCID: PMC8546700 DOI: 10.1128/msphere.00218-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Malaria vaccine candidates based on live, attenuated sporozoites have led to high levels of protection. However, their efficacy critically depends on the sporozoites' ability to reach and infect the host liver. Administration via mosquito inoculation is by far the most potent method for inducing immunity but highly impractical. Here, we observed that intradermal syringe-injected Plasmodium berghei sporozoites (syrSPZ) were 3-fold less efficient in migrating to and infecting mouse liver than mosquito-inoculated sporozoites (msqSPZ). This was related to a clustered dermal distribution (2-fold-decreased median distance between syrSPZ and msqSPZ) and, more importantly, a 1.4-fold (significantly)-slower and more erratic movement pattern. These erratic movement patterns were likely caused by alteration of dermal tissue morphology (>15-μm intercellular gaps) due to injection of fluid and may critically decrease sporozoite infectivity. These results suggest that novel microvolume-based administration technologies hold promise for replicating the success of mosquito-inoculated live, attenuated sporozoite vaccines.IMPORTANCE Malaria still causes a major burden on global health and the economy. The efficacy of live, attenuated malaria sporozoites as vaccine candidates critically depends on their ability to migrate to and infect the host liver. This work sheds light on the effect of different administration routes on sporozoite migration. We show that the delivery of sporozoites via mosquito inoculation is more efficient than syringe injection; however, this route of administration is highly impractical for vaccine purposes. Using confocal microscopy and automated imaging software, we demonstrate that syringe-injected sporozoites do cluster, move more slowly, and display more erratic movement due to alterations in tissue morphology. These findings indicate that microneedle-based engineering solutions hold promise for replicating the success of mosquito-inoculated live, attenuated sporozoite vaccines.
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Arora N, C Anbalagan L, Pannu AK. Towards Eradication of Malaria: Is the WHO's RTS,S/AS01 Vaccination Effective Enough? Risk Manag Healthc Policy 2021; 14:1033-1039. [PMID: 33737844 PMCID: PMC7966294 DOI: 10.2147/rmhp.s219294] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/26/2021] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Recent advances in mosquito eradication and antimalarial treatments have reduced the malaria burden only modestly. An effective malaria vaccine remains a high priority, but its development has several challenges. Among many potential candidates, the RTS,S/AS01 vaccine (MosquirixTM) remains the leading candidate. OBJECTIVE AND METHOD This review aims to understand the advances in the RTS,S/AS01 vaccine, and future comments regarding the vaccine's effectiveness in malaria eradication. Literature review for the past five decades was performed searching PubMed, EMBASE Ovid, and Cochrane Library, with using the following search items: ("malaria" OR "WHO's malaria" OR "Plasmodium falciparum" OR "RTS,S" OR "RTS,S/AS01" OR "RTS,S/AS02" OR "pre-erythrocytic malaria" OR "circumsporozoite" OR "Mosquirix") AND ("vaccine" OR "vaccination"). RESULTS RTS,S/AS01, a recombinant pre-erythrocytic vaccine containing Plasmodium falciparum surface-protein (circumsporozoite) antigen, is safe, well-tolerated, and immunogenic in children. Three doses, along with a booster, have a modest efficacy of about 36% in children (age 5-17 months) and about 26% in infants (age 6-12 weeks) against clinical malaria during a 48-month follow-up. However, the efficacy varies among population subgroups and with the parasite strain, it reduces without a booster and offers protection for a limited duration. Because of its potential cost-effectiveness and positive public health effect, the vaccine is being investigated in a pilot program for mortality benefits and broader deployment. CONCLUSION The RTS,S/AS01 vaccine prevents malaria; however, it should be considered another addition to the malaria-control program and not as an eradication tool because of its relatively low to modest efficacy.
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Affiliation(s)
- Navneet Arora
- Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | | | - Ashok K Pannu
- Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Abstract
Introduction: An effective vaccine against malaria forms a global health priority. Both naturally acquired immunity and sterile protection induced by irradiated sporozoite immunization were described decades ago. Still no vaccine exists that sufficiently protects children in endemic areas. Identifying immunological correlates of vaccine efficacy can inform rational vaccine design and potentially accelerate clinical development.Areas covered: We discuss recent research on immunological correlates of malaria vaccine efficacy, including: insights from state-of-the-art omics platforms and systems vaccinology analyses; functional anti-parasitic assays; pre-immunization predictors of vaccine efficacy; and comparison of correlates of vaccine efficacy against controlled human malaria infections (CHMI) and against naturally acquired infections.Expert Opinion: Effective vaccination may be achievable without necessarily understanding immunological correlates, but the relatively disappointing efficacy of malaria vaccine candidates in target populations is concerning. Hypothesis-generating omics and systems vaccinology analyses, alongside assessment of pre-immunization correlates, have the potential to bring about paradigm-shifts in malaria vaccinology. Functional assays may represent in vivo effector mechanisms, but have scarcely been formally assessed as correlates. Crucially, evidence is still meager that correlates of vaccine efficacy against CHMI correspond with those against naturally acquired infections in target populations. Finally, the diversity of immunological assays and efficacy endpoints across malaria vaccine trials remains a major confounder.
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Affiliation(s)
| | - Matthew B B McCall
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands.,Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
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Brunetti G, Padovani F, De Pastina A, Rotella C, Monahan A, Hoffman SL, Jongo SA, Abdulla S, Corradin G, Pluschke G, Daubenberger C, Hegner M. Nanotechnological immunoassay for rapid label-free analysis of candidate malaria vaccines. NANOSCALE 2021; 13:2338-2349. [PMID: 33438712 DOI: 10.1039/d0nr08083g] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Malaria is a life-threatening epidemic disease with half of the world's population at risk. Although its incidence rate has fallen since 2010, this ratio dramatically stalled between 2014 and 2018. New fast and optimized tools in vaccine analysis and seroconversion testing are critically needed. We developed a clinical diagnostic device based on piezo-actuated nanoresonators that perform as quantitative in situ calibrated nano-bio sensors for specific detection of multiple target molecules in serum samples. The immunoassay successfully diagnoses humoral immune responses induced by malaria vaccine candidates and reveals the timeline and stage of the infection. We applied the newly developed strategy to a variety of different samples, from pure antibody/vaccine solutions, to blood samples from clinical trials on both naïve and pre-exposed malaria volunteers from sub-Saharan countries. Our nanomechanical assay provides a direct one-step label-free quantitative immunoassay that is on par with the gold-standard, multi-step enzyme-linked immunosorbent assay (ELISA). We achieve a limit of detection of few pg ml-1, or sub-pM concentrations. The 6 μl sample volume allows more than 50 experiments from one finger prick. Furthermore, we simultaneously detected multiple analytes by differential functionalization of multiple sensors in parallel. The inherent differential read-out with in situ controls reduces false positive results. Due to the faster turnaround time, the minimal volume required and the automatized handling system, this technique has great potential for miniaturization and routine diagnostics in pandemic emergencies.
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Affiliation(s)
- Giulio Brunetti
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
| | - Francesco Padovani
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland. and Institute of Functional Epigenetics, Helmholtz Zentrum München (HMGU), Neuherberg 85764, Germany
| | - Annalisa De Pastina
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
| | - Chiara Rotella
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
| | - Amy Monahan
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
| | | | - 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
| | | | - Gerd Pluschke
- Medical Parasitology and Infection Biology Department, Molecular Immunology Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland and University of Basel, Switzerland
| | - Claudia Daubenberger
- University of Basel, Switzerland and Medical Parasitology and Infection Biology Department, Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland.
| | - Martin Hegner
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
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Lozano JM, Rodríguez Parra Z, Hernández-Martínez S, Yasnot-Acosta MF, Rojas AP, Marín-Waldo LS, Rincón JE. The Search of a Malaria Vaccine: The Time for Modified Immuno-Potentiating Probes. Vaccines (Basel) 2021; 9:vaccines9020115. [PMID: 33540947 PMCID: PMC7913233 DOI: 10.3390/vaccines9020115] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/22/2021] [Accepted: 01/25/2021] [Indexed: 12/25/2022] Open
Abstract
Malaria is a deadly disease that takes the lives of more than 420,000 people a year and is responsible for more than 229 million clinical cases globally. In 2019, 95% of malaria morbidity occurred in African countries. The development of a highly protective vaccine is an urgent task that remains to be solved. Many vaccine candidates have been developed, from the use of the entire attenuated and irradiated pre-erythrocytic parasite forms (or recombinantly expressed antigens thereof) to synthetic candidates formulated in a variety of adjuvants and delivery systems, however these have unfortunately proven a limited efficacy. At present, some vaccine candidates are finishing safety and protective efficacy trials, such as the PfSPZ and the RTS,S/AS01 which are being introduced in Africa. We propose a strategy for introducing non-natural elements into target antigens representing key epitopes of Plasmodium spp. Accordingly, chemical strategies and knowledge of host immunity to Plasmodium spp. have served as the basis. Evidence is obtained after being tested in experimental rodent models for malaria infection and recognized for human sera from malaria-endemic regions. This encourages us to propose such an immune-potentiating strategy to be further considered in the search for new vaccine candidates.
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Affiliation(s)
- José Manuel Lozano
- Grupo de Investigación Mimetismo Molecular de los Agentes Infecciosos, Departamento de Farmacia, Universidad Nacional de Colombia—Sede Bogotá, 111321 Bogota, Colombia;
- Correspondence: ; Tel.: +57-3102-504-657
| | - Zully Rodríguez Parra
- Grupo de Investigación Mimetismo Molecular de los Agentes Infecciosos, Departamento de Farmacia, Universidad Nacional de Colombia—Sede Bogotá, 111321 Bogota, Colombia;
| | - Salvador Hernández-Martínez
- Dirección de Infección e Inmunidad, Centro de Investigaciones Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, 62508 Cuernavaca, Morelos, Mexico;
| | - Maria Fernanda Yasnot-Acosta
- Grupo de Investigaciones Microbiológicas y Biomédicas de Córdoba, Universidad de Córdoba, 230002 Monteria, Colombia;
| | - Angela Patricia Rojas
- Grupo de Investigación Biología Celular y Autoinmuniad, Departamento de Farmacia, Universidad Nacional de Colombia-Sede Bogotá, 111321 Bogota, Colombia;
| | | | - Juan Edilberto Rincón
- Departamento de Ingeniería y Mecatrónica, Universidad Nacional de Colombia-Sede Bogotá, 111321 Bogota, Colombia;
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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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Schneider CG, Taylor JA, Sibilo MQ, Miura K, Mallory KL, Mann C, Karch C, Beck Z, Matyas GR, Long CA, Bergmann-Leitner E, Burkhard P, Angov E. Orientation of Antigen Display on Self-Assembling Protein Nanoparticles Influences Immunogenicity. Vaccines (Basel) 2021; 9:vaccines9020103. [PMID: 33572803 PMCID: PMC7911071 DOI: 10.3390/vaccines9020103] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 01/22/2021] [Accepted: 01/26/2021] [Indexed: 11/16/2022] Open
Abstract
Self-assembling protein nanoparticles (SAPN) serve as a repetitive antigen delivery platform with high-density epitope display; however, antigen characteristics such as size and epitope presentation can influence the immunogenicity of the assembled particle and are aspects to consider for a rationally designed effective vaccine. Here, we characterize the folding and immunogenicity of heterogeneous antigen display by integrating (a) dual-stage antigen SAPN presenting the P. falciparum (Pf) merozoite surface protein 1 subunit, PfMSP119, and Pf cell-traversal protein for ookinetes and sporozoites, PfCelTOS, in addition to (b) a homogenous antigen SAPN displaying two copies of PfCelTOS. Mice and rabbits were utilized to evaluate antigen-specific humoral and cellular induction as well as functional antibodies via growth inhibition of the blood-stage parasite. We demonstrate that antigen orientation and folding influence the elicited immune response, and when appropriately designed, SAPN can serve as an adaptable platform for an effective multi-antigen display.
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Affiliation(s)
- Cosette G. Schneider
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37831, USA
| | - Justin A. Taylor
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37831, USA
| | - Michael Q. Sibilo
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
- Parsons Corporation, Centreville, VA 20120, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, MD 20892, USA; (K.M.); (C.A.L.)
| | - Katherine L. Mallory
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
- Parsons Corporation, Centreville, VA 20120, USA
| | - Christopher Mann
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
- Parsons Corporation, Centreville, VA 20120, USA
| | - Christopher Karch
- Laboratory of Antigen and Adjuvants, US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.K.); (Z.B.); (G.R.M.)
- Henry Jackson Foundation, Bethesda, MD 20817, USA
| | - Zoltan Beck
- Laboratory of Antigen and Adjuvants, US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.K.); (Z.B.); (G.R.M.)
- Henry Jackson Foundation, Bethesda, MD 20817, USA
| | - Gary R. Matyas
- Laboratory of Antigen and Adjuvants, US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.K.); (Z.B.); (G.R.M.)
| | - Carole A. Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, MD 20892, USA; (K.M.); (C.A.L.)
| | - Elke Bergmann-Leitner
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
| | | | - Evelina Angov
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
- Correspondence: ; Tel.: +1-301-319-9614
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Tumbo AM, Schindler T, Dangy JP, Orlova-Fink N, Bieri JR, Mpina M, Milando FA, Juma O, Hamad A, Nyakarungu E, Chemba M, Mtoro A, Ramadhan K, Olotu A, Makweba D, Mgaya S, Stuart K, Perreau M, Stapleton JT, Jongo S, Hoffman SL, Tanner M, Abdulla S, Daubenberger C. Role of human Pegivirus infections in whole Plasmodium falciparum sporozoite vaccination and controlled human malaria infection in African volunteers. Virol J 2021; 18:28. [PMID: 33499880 PMCID: PMC7837505 DOI: 10.1186/s12985-021-01500-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 01/20/2021] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Diverse vaccination outcomes and protection levels among different populations pose a serious challenge to the development of an effective malaria vaccine. Co-infections are among many factors associated with immune dysfunction and sub-optimal vaccination outcomes. Chronic, asymptomatic viral infections can contribute to the modulation of vaccine efficacy through various mechanisms. Human Pegivirus-1 (HPgV-1) persists in immune cells thereby potentially modulating immune responses. We investigated whether Pegivirus infection influences vaccine-induced responses and protection in African volunteers undergoing whole P. falciparum sporozoites-based malaria vaccination and controlled human malaria infections (CHMI). METHODS HPgV-1 prevalence was quantified by RT-qPCR in plasma samples of 96 individuals before, post vaccination with PfSPZ Vaccine and after CHMI in cohorts from Tanzania and Equatorial Guinea. The impact of HPgV-1 infection was evaluated on (1) systemic cytokine and chemokine levels measured by Luminex, (2) PfCSP-specific antibody titers quantified by ELISA, (3) asexual blood-stage parasitemia pre-patent periods and parasite multiplication rates, (4) HPgV-1 RNA levels upon asexual blood-stage parasitemia induced by CHMI. RESULTS The prevalence of HPgV-1 was 29.2% (28/96) and sequence analysis of the 5' UTR and E2 regions revealed the predominance of genotypes 1, 2 and 5. HPgV-1 infection was associated with elevated systemic levels of IL-2 and IL-17A. Comparable vaccine-induced anti-PfCSP antibody titers, asexual blood-stage multiplication rates and pre-patent periods were observed in HPgV-1 positive and negative individuals. However, a tendency for higher protection levels was detected in the HPgV-1 positive group (62.5%) compared to the negative one (51.6%) following CHMI. HPgV-1 viremia levels were not significantly altered after CHMI. CONCLUSIONS HPgV-1 infection did not alter PfSPZ Vaccine elicited levels of PfCSP-specific antibody responses and parasite multiplication rates. Ongoing HPgV-1 infection appears to improve to some degree protection against CHMI in PfSPZ-vaccinated individuals. This is likely through modulation of immune system activation and systemic cytokines as higher levels of IL-2 and IL17A were observed in HPgV-1 infected individuals. CHMI is safe and well tolerated in HPgV-1 infected individuals. Identification of cell types and mechanisms of both silent and productive infection in individuals will help to unravel the biology of this widely present but largely under-researched virus.
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Affiliation(s)
- Anneth-Mwasi Tumbo
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Bagamoyo, Tanzania
- Department of Medical Parasitology and Infection Biology, Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Socinstr. 57, 4002, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Tobias Schindler
- Department of Medical Parasitology and Infection Biology, Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Socinstr. 57, 4002, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jean-Pierre Dangy
- Department of Medical Parasitology and Infection Biology, Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Socinstr. 57, 4002, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Nina Orlova-Fink
- Department of Medical Parasitology and Infection Biology, Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Socinstr. 57, 4002, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jose Raso Bieri
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Bioko Norte, Equatorial Guinea
| | - Maximillian Mpina
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Bagamoyo, Tanzania
- Department of Medical Parasitology and Infection Biology, Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Socinstr. 57, 4002, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Bioko Norte, Equatorial Guinea
| | - Florence A Milando
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Omar Juma
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Ali Hamad
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Bagamoyo, Tanzania
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Bioko Norte, Equatorial Guinea
| | - Elizabeth Nyakarungu
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Bagamoyo, Tanzania
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Bioko Norte, Equatorial Guinea
| | - Mwajuma Chemba
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Bagamoyo, Tanzania
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Bioko Norte, Equatorial Guinea
| | - Ali Mtoro
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Bagamoyo, Tanzania
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Bioko Norte, Equatorial Guinea
| | - Kamaka Ramadhan
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Bagamoyo, Tanzania
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Bioko Norte, Equatorial Guinea
| | - Ally Olotu
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Bagamoyo, Tanzania
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Bioko Norte, Equatorial Guinea
| | - Damas Makweba
- Dar-Es-Salaam Institute of Technology, Dar-Es-Salaam, Tanzania
- Tanzania Education and Research Networks, Dar-Es-Salaam, Tanzania
- Tanzania Commission for Science and Technology, Dar-Es-Salaam, Tanzania
| | - Stephen Mgaya
- Tanzania Education and Research Networks, Dar-Es-Salaam, Tanzania
- Tanzania Commission for Science and Technology, Dar-Es-Salaam, Tanzania
| | - Kenneth Stuart
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, 307 Westlake Avenue, N. Suite 500, Seattle, WA, 98109, USA
| | | | - Jack T Stapleton
- Iowa City Veterans Administration and the University of Iowa, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Said Jongo
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Bagamoyo, Tanzania
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Bioko Norte, Equatorial Guinea
| | | | - Marcel Tanner
- Department of Medical Parasitology and Infection Biology, Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Socinstr. 57, 4002, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Salim Abdulla
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Bagamoyo, Tanzania
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Bioko Norte, Equatorial Guinea
| | - Claudia Daubenberger
- Department of Medical Parasitology and Infection Biology, Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Socinstr. 57, 4002, Basel, Switzerland.
- University of Basel, Basel, Switzerland.
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50
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Ferluga J, Singh I, Rout S, Al-Qahtani A, Yasmin H, Kishore U. Immune Responses in Malaria and Vaccine Strategies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1313:273-291. [PMID: 34661899 DOI: 10.1007/978-3-030-67452-6_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Malaria is a pandemic with nearly half of global population at risk, caused by parasite Plasmodium species, particularly P. falciparum with a high morbidity and mortality, especially among children. There is an urgent need for development of population protective vaccines, such as in sub-Saharan low-income countries, where P. falciparum malaria is endemic. After years of endeavour with children and adults for safety and efficacy clinical trials, the P. falciparum circumsporozoite protein antigen, is targeted by specific antibodies induced by recombinant vaccine, called TRS,S. TRS,S has been authorized by WHO and Malawi Government to be the first malaria vaccine for up to 2 years of aged children for protection against malaria. Other malaria vaccines in clinical trials are also very promising candidates, including the original live, X-ray attenuated P-sporozoite vaccine, inducing antigen-specific T cell immunity at liver stage. Malaria parasite at blood symptomatic stage is targeted by specific antibodies to parasite-infected erythrocytes, which are important against pathogenic placenta-infected erythrocyte sequestration. Here, the demographic distribution of Plasmodium species and their pathogenicity in infected people are discussed. The role of innate phagocytic cells and malaria antigen specific T cell immunity, as well as that of specific antibody production by B cells are highlighted. The paramount role of cytotoxic CD8+ T cellular immunity in malaria people protection is also included.
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Affiliation(s)
- Janez Ferluga
- Biosciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UK
| | - Iesha Singh
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Sashmita Rout
- Department of Physiology, All-India Institute of Medical Sciences, Bhubaneswar, India
| | - Ahmed Al-Qahtani
- Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Hadida Yasmin
- Immunology and Cell Biology Laboratory, Department of Zoology, Cooch Behar Panchanan Barma University, Cooch Behar, West Bengal, India
| | - Uday Kishore
- Biosciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UK
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