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Hossain MJ, Svennerholm AM, Carlin N, D’Alessandro U, Wierzba TF. A Perspective on the Strategy for Advancing ETVAX ®, An Anti-ETEC Diarrheal Disease Vaccine, into a Field Efficacy Trial in Gambian Children: Rationale, Challenges, Lessons Learned, and Future Directions. Microorganisms 2023; 12:90. [PMID: 38257916 PMCID: PMC10819518 DOI: 10.3390/microorganisms12010090] [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: 11/15/2023] [Revised: 12/22/2023] [Accepted: 12/23/2023] [Indexed: 01/24/2024] Open
Abstract
For the first time in over 20 years, an Enterotoxigenic Escherichia coli (ETEC) vaccine candidate, ETVAX®, has advanced into a phase 2b field efficacy trial for children 6-18 months of age in a low-income country. ETVAX® is an inactivated whole cell vaccine that has gone through a series of clinical trials to provide a rationale for the design elements of the Phase 2b trial. This trial is now underway in The Gambia and will be a precursor to an upcoming pivotal phase 3 trial. To reach this point, numerous findings were brought together to define factors such as safe and immunogenic doses for children, and the possible benefit of a mucosal adjuvant, double mutant labile toxin (dmLT). Considering the promising but still underexplored potential of inactivated whole cells in oral vaccination, we present a perspective compiling key observations from past ETVAX® trials that informed The Gambian trial design. This report will update the trial's status and explore future directions for ETEC vaccine trials. Our aim is to provide not only an update on the most advanced ETEC vaccine candidate but also to offer insights beneficial for the development of other much-needed oral whole-cell vaccines against enteric and other pathogens.
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Affiliation(s)
- M. Jahangir Hossain
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, Banjul P.O. Box 273, The Gambia
| | - Ann-Mari Svennerholm
- Department of Microbiology and Immunology, Gothenburg University Research Institute (GUVAX), Gothenburg University, 40530 Gothenburg, Sweden
| | - Nils Carlin
- Scandinavian Biopharma, Industrivägen 1, 17148 Solna, Sweden
| | - Umberto D’Alessandro
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, Banjul P.O. Box 273, The Gambia
| | - Thomas F. Wierzba
- Section on Infectious Diseases, Department of Internal Medicine, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
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Montero DA, Vidal RM, Velasco J, George S, Lucero Y, Gómez LA, Carreño LJ, García-Betancourt R, O’Ryan M. Vibrio cholerae, classification, pathogenesis, immune response, and trends in vaccine development. Front Med (Lausanne) 2023; 10:1155751. [PMID: 37215733 PMCID: PMC10196187 DOI: 10.3389/fmed.2023.1155751] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 04/14/2023] [Indexed: 05/24/2023] Open
Abstract
Vibrio cholerae is the causative agent of cholera, a highly contagious diarrheal disease affecting millions worldwide each year. Cholera is a major public health problem, primarily in countries with poor sanitary conditions and regions affected by natural disasters, where access to safe drinking water is limited. In this narrative review, we aim to summarize the current understanding of the evolution of virulence and pathogenesis of V. cholerae as well as provide an overview of the immune response against this pathogen. We highlight that V. cholerae has a remarkable ability to adapt and evolve, which is a global concern because it increases the risk of cholera outbreaks and the spread of the disease to new regions, making its control even more challenging. Furthermore, we show that this pathogen expresses several virulence factors enabling it to efficiently colonize the human intestine and cause cholera. A cumulative body of work also shows that V. cholerae infection triggers an inflammatory response that influences the development of immune memory against cholera. Lastly, we reviewed the status of licensed cholera vaccines, those undergoing clinical evaluation, and recent progress in developing next-generation vaccines. This review offers a comprehensive view of V. cholerae and identifies knowledge gaps that must be addressed to develop more effective cholera vaccines.
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Affiliation(s)
- David A. Montero
- Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Roberto M. Vidal
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Instituto Milenio de Inmunología e Inmunoterapia, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Juliana Velasco
- Unidad de Paciente Crítico, Clínica Hospital del Profesor, Santiago, Chile
- Programa de Formación de Especialista en Medicina de Urgencia, Universidad Andrés Bello, Santiago, Chile
| | - Sergio George
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Yalda Lucero
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Departamento de Pediatría y Cirugía Infantil, Hospital Dr. Roberto del Rio, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Leonardo A. Gómez
- Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Leandro J. Carreño
- Instituto Milenio de Inmunología e Inmunoterapia, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Programa de Inmunología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Richard García-Betancourt
- Programa de Inmunología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Miguel O’Ryan
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
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Sit B, Fakoya B, Waldor MK. Emerging Concepts in Cholera Vaccine Design. Annu Rev Microbiol 2022; 76:681-702. [PMID: 35759873 DOI: 10.1146/annurev-micro-041320-033201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cholera is a severe diarrheal disease caused by the bacterium Vibrio cholerae and constitutes a significant public health threat in many areas of the world. V. cholerae infection elicits potent and long-lasting immunity, and efforts to develop cholera vaccines have been ongoing for more than a century. Currently available inactivated two-dose oral cholera vaccines are increasingly deployed to both prevent and actively curb cholera outbreaks, and they are key components of the global effort to eradicate cholera. However, these killed whole-cell vaccines have several limitations, and a variety of new oral and nonoral cholera vaccine platforms have recently been developed. Here, we review emerging concepts in cholera vaccine design and implementation that have been driven by insights from human and animal studies. As a prototypical vaccine-preventable disease, cholera continues to be an excellent target for the development and application of cutting-edge technologies and platforms that may transform vaccinology. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Brandon Sit
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA; .,Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Bolutife Fakoya
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA; .,Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Matthew K Waldor
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA; .,Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA.,Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Massachusetts, USA.,Howard Hughes Medical Institute, Bethesda, Maryland, USA
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Abstract
Cholera, caused by Vibrio cholerae, persists in developing countries due to inadequate access to safe water, sanitation, and hygiene. There are approximately 4 million cases and 143,000 deaths each year due to cholera. The disease is transmitted fecally-orally via contaminated food or water. Severe dehydrating cholera can progress to hypovolemic shock due to the rapid loss of fluids and electrolytes, which requires a rapid infusion of intravenous (i.v.) fluids. The case fatality rate exceeds 50% without proper clinical management but can be less than 1% with prompt rehydration and antibiotics. Oral cholera vaccines (OCVs) serve as a major component of an integrated control package during outbreaks or within zones of endemicity. Water, sanitation, and hygiene (WaSH); health education; and prophylactic antibiotic treatment are additional components of the prevention and control of cholera. The World Health Organization (WHO) and the Global Task Force for Cholera Control (GTFCC) have set an ambitious goal of eliminating cholera by 2030 in high-risk areas.
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Mwaba J, Chisenga CC, Xiao S, Ng'ombe H, Banda E, Shea P, Mabula-Bwalya C, Mwila-Kazimbaya K, Laban NM, Alabi P, Chirwa-Chobe M, Simuyandi M, Harris J, Iyer AS, Bosomprah S, Scalzo P, Murt KN, Ram M, Kwenda G, Ali M, Sack DA, Chilengi R, Debes AK. Serum vibriocidal responses when second doses of oral cholera vaccine are delayed 6 months in Zambia. Vaccine 2021; 39:4516-4523. [PMID: 34217572 DOI: 10.1016/j.vaccine.2021.06.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 11/28/2022]
Abstract
Two-dose killed oral cholera vaccines (OCV) are currently being used widely to control cholera. The standard dose-interval for OCV is 2 weeks; however, during emergency use of the vaccine, it may be more appropriate to use the available doses to quickly give a single dose to more people and give a delayed second dose when more vaccine becomes available. This study is an open label, randomized, phase 2 clinical trial of the vibriocidal response induced by OCV, comparing the responses when the second dose was given either 2 weeks (standard dose interval) or 6 months (extended dose interval) after the first dose. Vaccine was administered to healthy participants > 1 year of age living in the Lukanga Swamps area of Zambia. Three age cohorts (<5 years, 5-14 years, and ≥ 15 years) were randomized to the either dose-interval. The primary outcome was the vibriocidal GMT 14 days after the second dose. 156 of 172 subjects enrolled in the study were included in this analysis. The Inaba vibriocidal titers were not significantly different 14 days post dose two for a standard dose-interval GMT: 45.6 (32-64.9), as compared to the GMT 47.6 (32.6-69.3), for the extended dose-interval, (p = 0.87). However, the Ogawa vibriocidal GMTs were significantly higher 14 days post dose two for the extended-dose interval at 87.6 (58.9-130.4) compared to the standard dose-interval group at 49.7 (34.1-72.3), p = 0.04. Vibriocidal seroconversion rates (a > 4-fold rise in vibriocidal titer) were not significantly different between dose-interval groups. This study demonstrated that vibriocidal titers 14 days after a second dose when given at an extended\ dose interval were similar to the standard dose-interval. The findings suggest that a flexible dosing schedule may be considered when epidemiologically appropriate. The trial was registered at Clinical Trials.gov (NCT03373669).
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Affiliation(s)
- John Mwaba
- Research Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia; Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Lusaka, Zambia
| | | | - Shaoming Xiao
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Harriet Ng'ombe
- Research Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia; Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Lusaka, Zambia
| | - Elena Banda
- Research Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Patrick Shea
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - Katayi Mwila-Kazimbaya
- Research Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia; Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Lusaka, Zambia
| | - Natasha Makabilo Laban
- Research Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia; London School of Hygiene and Tropical Medicine, United Kingdom
| | - Peter Alabi
- Research Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Masuzyo Chirwa-Chobe
- Research Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Michelo Simuyandi
- Research Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Jason Harris
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Anita S Iyer
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Samuel Bosomprah
- Research Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Paul Scalzo
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Kelsey N Murt
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Malathi Ram
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Geoffrey Kwenda
- Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Lusaka, Zambia
| | - Mohammad Ali
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - David A Sack
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Roma Chilengi
- Research Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Amanda K Debes
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
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Gallandat K, Jeandron A, Ross I, Mufitini Saidi J, Bashige Rumedeka B, Lumami Kapepula V, Cousens S, Allen E, MacDougall A, Cumming O. The impact of improved water supply on cholera and diarrhoeal diseases in Uvira, Democratic Republic of the Congo: a protocol for a pragmatic stepped-wedge cluster randomised trial and economic evaluation. Trials 2021; 22:408. [PMID: 34154636 PMCID: PMC8215491 DOI: 10.1186/s13063-021-05249-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 04/03/2021] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION Diarrhoeal disease remains a leading cause of mortality and morbidity worldwide. Cholera alone is estimated to cause 95,000 deaths per year, most of which occur in endemic settings with inadequate water access. Whilst a global strategy to eliminate cholera by 2030 calls for investment in improved drinking water services, there is limited rigorous evidence for the impact of improved water supply on endemic cholera transmission in low-income urban settings. Our protocol is designed to deliver a pragmatic health impact evaluation of a large-scale water supply intervention in Uvira (Democratic Republic of the Congo), a cholera transmission hotspot. METHODS/DESIGN A stepped-wedge cluster randomised trial (SW-CRT) was designed to evaluate the impact of a large-scale drinking water supply intervention on cholera incidence among the 280,000 inhabitants of Uvira. The city was divided into 16 clusters, where new community and household taps will be installed following a randomised sequence over a transition period of up to 8 weeks in each cluster. The primary trial outcomes are the monthly incidence of "confirmed" cholera cases (patients testing positive by rapid detection kit) and of "suspected" cholera cases (patients admitted to the cholera treatment centre). Concurrent process and economic evaluations will provide further information on the context, costs, and efficiency of the intervention. DISCUSSION In this protocol, we describe a pragmatic approach to conducting rigorous research to assess the impacts of a complex water supply intervention on severe diarrhoeal disease and cholera in an unstable, low-resource setting representative of cholera-affected areas. In particular, we discuss a series of pre-identified risks and linked mitigation strategies as well as the value of combining different data collection methods and preparation of multiple analysis scenarios to account for possible deviations from the protocol. The study described here has the potential to provide robust evidence to support more effective cholera control in challenging, high-burden settings. TRIAL REGISTRATION This trial is registered on clinicaltrials.gov ( NCT02928341 , 10th October 2016) and has received ethics approval from the London School of Hygiene and Tropical Medicine (8913, 10603) and from the Ethics Committee from the School of Public Health, University of Kinshasa, Democratic Republic of the Congo (ESP/CE/088/2015).
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Affiliation(s)
- Karin Gallandat
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK.
| | - Aurélie Jeandron
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Ian Ross
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Jaime Mufitini Saidi
- Ministère de la Santé Publique, Division Provinciale de la Santé Publique, District Sanitaire d'Uvira, Uvira, South Kivu, Democratic Republic of the Congo
| | - Baron Bashige Rumedeka
- Ministère de la Santé Publique, Division Provinciale de la Santé Publique, District Sanitaire d'Uvira, Uvira, South Kivu, Democratic Republic of the Congo
| | - Vercus Lumami Kapepula
- Department of Hydrology, Centre de Recherche en Hydrobiologie, Uvira, South Kivu, Democratic Republic of the Congo
| | - Simon Cousens
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Elizabeth Allen
- Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, UK
| | - Amy MacDougall
- Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, UK
| | - Oliver Cumming
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
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Abstract
Cholera infections caused by the gamma-proteobacterium Vibrio cholerae have ravaged human populations for centuries, and cholera pandemics have afflicted every corner of the globe. Fortunately, interventions such as oral rehydration therapy, antibiotics/antimicrobials, and vaccines have saved countless people afflicted with cholera, and new interventions such as probiotics and phage therapy are being developed as promising approaches to treat even more cholera infections. Although current therapies are mostly effective and can reduce disease transmission, cholera outbreaks remain deadly, as was seen during recent outbreaks in Haiti, Ethiopia, and Yemen. This is due to significant underlying political and socioeconomic complications, including shortages of vaccines and clean food and water and a lack of health surveillance. In this review, we highlight the strengths and weaknesses of current cholera therapies, discuss emerging technologies, and argue that a multi-pronged, flexible approach is needed to continue to reduce the worldwide burden of cholera.
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Affiliation(s)
- Brian Y Hsueh
- Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
| | - Christopher M Waters
- Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
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