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Diawara H, Healy SA, Mwakingwe-Omari A, Issiaka D, Diallo A, Traore S, Soumbounou IH, Gaoussou S, Zaidi I, Mahamar A, Attaher O, Fried M, Wylie BJ, Mohan R, Doan V, Doritchamou JYA, Dolo A, Morrison RD, Wang J, Hu Z, Rausch KM, Zeguime A, Murshedkar T, Kc N, Sim BKL, Billingsley PF, Richie TL, Hoffman SL, Dicko A, Duffy PE. Safety and efficacy of PfSPZ Vaccine against malaria in healthy adults and women anticipating pregnancy in Mali: two randomised, double-blind, placebo-controlled, phase 1 and 2 trials. THE LANCET. INFECTIOUS DISEASES 2024:S1473-3099(24)00360-8. [PMID: 39153490 DOI: 10.1016/s1473-3099(24)00360-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/07/2024] [Accepted: 05/30/2024] [Indexed: 08/19/2024]
Abstract
BACKGROUND Plasmodium falciparum parasitaemia during pregnancy causes maternal, fetal, and infant mortality. Poor pregnancy outcomes are related to blood-stage parasite sequestration and the ensuing inflammatory response in the placenta, which decreases over successive pregnancies. A radiation-attenuated, non-replicating, whole-organism vaccine based on P falciparum sporozoites (PfSPZ Vaccine) has shown efficacy at preventing infection in African adults. Here, we aimed to examine vaccine safety and efficacy of the PfSPZ Vaccine in adults and women who anticipated conception. METHODS Two randomised, double-blind, placebo-controlled trials (phase 1 MLSPZV3 and phase 2 MLSPZV4) were conducted at a clinical research centre in Mali. MLSPZV3 included adults aged 18-35 years and MLSPZV4 included non-pregnant women aged 18-38 years who anticipated conception within a year of enrolment. In MLSPZV3, participants were stratified by village and randomly assigned (2:1) using block randomisation to receive three doses of 9 × 105 PfSPZ Vaccine or saline placebo at weeks 0, 1, and 4 (4-week schedule) or at weeks 0, 8, and 16 (16-week schedule) and a booster dose around 1 year later. In MLSPZV4, women received presumptive artemether-lumefantrine twice per day for 3 days 2 weeks before dose one and were randomly assigned (1:1:1) using block randomisation to receive three doses of 9 × 105 or 1·8 × 106 PfSPZ Vaccine or saline placebo all administered at weeks 0, 1, and 4 (4-week schedule). Participants in both studies received artemether-lumefantrine 2 weeks before dose three and additionally 2 weeks before dose four (booster dose) in MLSPZV3. Investigators and participants were masked to group assignment. The primary outcome, assessed in the as-treated population, was PfSPZ Vaccine safety and tolerability within 7 days after each dose. The secondary outcome, assessed in the modified intention-to-treat population, was vaccine efficacy against P falciparum parasitaemia (defined as the time-to-first positive blood smear) from dose three until the end of transmission season. In exploratory analyses, MLSPZV4 evaluated incidence of maternal obstetric and neonatal outcomes as safety outcomes, and vaccine efficacy against P falciparum parasitaemia during pregnancy (defined as time-to-first positive blood smear post-conception). In MLSPZV4, women were followed at least once a month with human chorionic gonadotropin testing, and those who became pregnant received standard of care (including intermittent presumptive sulfadoxine-pyrimethamine antimalarial drugs after the first trimester) during routine antenatal visits. These studies are registered with ClinicalTrials.gov, NCT03510481 and NCT03989102. FINDINGS Participants were enrolled for vaccination during the onset of malaria seasons for two sequential studies conducted from 2018 to 2019 for MLSPZV3 and from 2019 to 2021 for MLSPZV4, with follow-up during malaria seasons across 2 years. In MLSPZV3, 478 adults were assessed for eligibility, of whom 220 were enrolled between May 30 and June 12, 2018, and then between Aug 13 and Aug 18, 2018, and 210 received dose one. 66 (96%) of 69 participants who received the 16-week schedule and 68 (97%) of 70 who received the 4-week schedule of the 9 × 105 PfSPZ Vaccine and 70 (99%) of 71 who received saline completed all three doses in year 1. In MLSPZV4, 407 women were assessed for eligibility, of whom 324 were enrolled from July 3 to July 27, 2019, and 320 received dose one of presumptive artemether-lumefantrine. 300 women were randomly assigned with 100 per group (PfSPZ Vaccine 9 × 105, 1·8 × 106, or saline) receiving dose one. First trimester miscarriages were the most commonly reported serious adverse event but occurred at a similar rate across study groups (eight [15%] of 54 with 9 × 105 PfSPZ Vaccine, 12 [21%] of 58 with 1·8 × 106 PfSPZ Vaccine, and five [12%] of 43 with saline). One unrelated maternal death occurred 425 days after the last vaccine dose in the 1·8 × 106 PfSPZ Vaccine group due to peritonitis shortly after childbirth. Most related adverse events reported in MLSPZV3 and MLSPZV4 were mild (grade 1) and frequency of adverse events in the PfSPZ Vaccine groups did not differ from that in the saline group. Two unrelated serious adverse events occurred in MLSPZV3 (one participant had appendicitis in the 9 × 105 PfSPZ Vaccine group and the other in the saline group died due to a road traffic accident). In MLSPZV3, the 9 × 105 PfSPZ Vaccine did not show vaccine efficacy against parasitaemia with the 4-week (27% [95% CI -18 to 55] in year 1 and 42% [-5 to 68] in year 2) and 16-week schedules (16% [-34 to 48] in year 1 and -14% [-95 to 33] in year 2); efficacies were similar or worse against clinical malaria compared with saline. In MLSPZV4, the PfSPZ Vaccine showed significant efficacy against parasitaemia at doses 9 × 105 (41% [15 to 59]; p=0·0069 in year 1 and 61% [36 to 77]; p=0·0011 in year 2) and 1·8 × 106 (54% [34 to 69]; p<0·0001 in year 1 and 45% [13 to 65]; p=0·029 in year 2); and against clinical malaria at doses 9 × 105 (47% [20 to 65]; p=0·0045 in year 1 and 56% [22 to 75]; p=0·0081 in year 2) and 1·8 × 106 (48% [22 to 65]; p=0·0013 in year 1 and 40% [2 to 64]; p=0·069 in year 2). Vaccine efficacy against post-conception P falciparum parasitaemia during first pregnancies that arose in the 2-year follow-up was 57% (14 to 78; p=0·017) in the 9 × 105 PfSPZ Vaccine group versus 49% (3 to 73; p=0·042) in the 1·8 × 106 PfSPZ Vaccine group. Among 55 women who became pregnant within 24 weeks after dose three, vaccine efficacy against parasitaemia was 65% (23 to 84; p=0·0088) with the 9 × 105 PfSPZ Vaccine and 86% (64 to 94; p<0·0001) with the 1·8 × 106 PfSPZ Vaccine. When combined in a post-hoc analysis, women in the PfSPZ Vaccine groups had a non-significantly reduced time-to-first pregnancy after dose one compared with those in the saline group (log-rank test p=0·056). Exploratory maternal obstetric and neonatal outcomes did not differ significantly between vaccine groups and saline. INTERPRETATION PfSPZ Vaccine was safe and well tolerated in adults in Mali. The 9 × 105 and 1·8 × 106 doses of PfSPZ Vaccine administered as per the 4-week schedule, which incorporated presumptive antimalarial treatment before the first vaccine dose, showed significant efficacy against P falciparum parasitaemia and clinical malaria for two malaria transmission seasons in women of childbearing age and against pregnancy malaria. PfSPZ Vaccine without presumptive antimalarial treatment before the first vaccine dose did not show efficacy. FUNDING National Institute of Allergy and Infectious Diseases, National Institutes of Health, and Sanaria.
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Affiliation(s)
- Halimatou Diawara
- Malaria Research and Training Center, University of Sciences, Techniques, and Technologies of Bamako, 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
| | - Agnes Mwakingwe-Omari
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Djibrilla Issiaka
- Malaria Research and Training Center, University of Sciences, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Aye Diallo
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Seydou Traore
- Malaria Research and Training Center, University of Sciences, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Ibrahim H Soumbounou
- Malaria Research and Training Center, University of Sciences, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Santara Gaoussou
- Malaria Research and Training Center, University of Sciences, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Irfan Zaidi
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Almahamoudou Mahamar
- Malaria Research and Training Center, University of Sciences, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Oumar Attaher
- Malaria Research and Training Center, University of Sciences, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Blair J Wylie
- Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Rathy Mohan
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Viyada Doan
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Justin Y A Doritchamou
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Amagana Dolo
- Malaria Research and Training Center, University of Sciences, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Robert D Morrison
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jing Wang
- Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Zonghui Hu
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kelly M Rausch
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Amatigue Zeguime
- Malaria Research and Training Center, University of Sciences, Techniques, and Technologies of Bamako, Bamako, Mali
| | | | | | | | | | | | | | - Alassane Dicko
- Malaria Research and Training Center, University of Sciences, Techniques, and Technologies of Bamako, 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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Frischknecht F, Rayner JC, Waters AP. 20 years of BioMalPar: Building a collaborative malaria research network. Trends Parasitol 2024; 40:657-659. [PMID: 39025766 DOI: 10.1016/j.pt.2024.06.016] [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: 06/20/2024] [Accepted: 06/24/2024] [Indexed: 07/20/2024]
Abstract
In 2004 the first annual BioMalPar meeting was held at EMBL Heidelberg, bringing together researchers from around the world with the goal of building connections between malaria research groups in Europe. Twenty years on it is time to reflect on what was achieved and to look ahead to the future.
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Affiliation(s)
- Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany; German Center for Infection Research, partner site Heidelberg, Heidelberg, Germany
| | - Julian C Rayner
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
| | - Andrew P Waters
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity, and Inflammation, University of Glasgow, Glasgow, UK.
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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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Miura K, Flores-Garcia Y, Long CA, Zavala F. Vaccines and monoclonal antibodies: new tools for malaria control. Clin Microbiol Rev 2024; 37:e0007123. [PMID: 38656211 PMCID: PMC11237600 DOI: 10.1128/cmr.00071-23] [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] [Indexed: 04/26/2024] Open
Abstract
SUMMARYMalaria remains one of the biggest health problems in the world. While significant reductions in malaria morbidity and mortality had been achieved from 2000 to 2015, the favorable trend has stalled, rather significant increases in malaria cases are seen in multiple areas. In 2022, there were 249 million estimated cases, and 608,000 malaria-related deaths, mostly in infants and children aged under 5 years, globally. Therefore, in addition to the expansion of existing anti-malarial control measures, it is critical to develop new tools, such as vaccines and monoclonal antibodies (mAbs), to fight malaria. In the last 2 years, the first and second malaria vaccines, both targeting Plasmodium falciparum circumsporozoite proteins (PfCSP), have been recommended by the World Health Organization to prevent P. falciparum malaria in children living in moderate to high transmission areas. While the approval of the two malaria vaccines is a considerable milestone in vaccine development, they have much room for improvement in efficacy and durability. In addition to the two approved vaccines, recent clinical trials with mAbs against PfCSP, blood-stage vaccines against P. falciparum or P. vivax, and transmission-blocking vaccine or mAb against P. falciparum have shown promising results. This review summarizes the development of the anti-PfCSP vaccines and mAbs, and recent topics in the blood- and transmission-blocking-stage vaccine candidates and mAbs. We further discuss issues of the current vaccines and the directions for the development of next-generation vaccines.
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Affiliation(s)
- Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Yevel Flores-Garcia
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Malaria Research Institute, Baltimore, Maryland, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Fidel Zavala
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Malaria Research Institute, Baltimore, Maryland, USA
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Marques-da-Silva C, Schmidt-Silva C, Kurup SP. Hepatocytes and the art of killing Plasmodium softly. Trends Parasitol 2024; 40:466-476. [PMID: 38714463 PMCID: PMC11156546 DOI: 10.1016/j.pt.2024.04.004] [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: 02/14/2024] [Revised: 04/05/2024] [Accepted: 04/07/2024] [Indexed: 05/09/2024]
Abstract
The Plasmodium parasites that cause malaria undergo asymptomatic development in the parenchymal cells of the liver, the hepatocytes, prior to infecting erythrocytes and causing clinical disease. Traditionally, hepatocytes have been perceived as passive bystanders that allow hepatotropic pathogens such as Plasmodium to develop relatively unchallenged. However, now there is emerging evidence suggesting that hepatocytes can mount robust cell-autonomous immune responses that target Plasmodium, limiting its progression to the blood and reducing the incidence and severity of clinical malaria. Here we discuss our current understanding of hepatocyte cell-intrinsic immune responses that target Plasmodium and how these pathways impact malaria.
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Affiliation(s)
- Camila Marques-da-Silva
- Department of Cellular Biology, University of Georgia, Athens, GA, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - Clyde Schmidt-Silva
- Department of Cellular Biology, University of Georgia, Athens, GA, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - Samarchith P Kurup
- Department of Cellular Biology, University of Georgia, Athens, GA, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA.
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Indrihutami K, Chand K, Fahmia R, Rahardjani M, Wulandari F, Subekti D, Noviyanti R, Soebandrio A, Mallisa NT, Mardika IM, Budiman W, Suriswan I, Ertanto Y, Chen MC, Murshedkar T, Abebe Y, Sim BKL, Hoffman SL, Richie TL, Chen S, Elyazar IRF, Ekawati LL, Baird JK, Nelwan EJ. Implementation of a Randomized, Placebo-Controlled Trial of Live Attenuated Malaria Sporozoite Vaccines in an Indonesian Military Study Population. Am J Trop Med Hyg 2024; 110:892-901. [PMID: 38531102 PMCID: PMC11066349 DOI: 10.4269/ajtmh.23-0597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 11/24/2023] [Indexed: 03/28/2024] Open
Abstract
Malaria eradication efforts prioritize safe and efficient vaccination strategies, although none with high-level efficacy against malaria infection are yet available. Among several vaccine candidates, Sanaria® PfSPZ Vaccine and Sanaria PfSPZ-CVac are, respectively, live radiation- and chemo-attenuated sporozoite vaccines designed to prevent infection with Plasmodium falciparum, the leading cause of malaria-related morbidity and mortality. We are conducting a randomized normal saline placebo-controlled trial called IDSPZV1 that will analyze the safety, tolerability, immunogenicity, and efficacy of PfSPZ Vaccine and PfSPZ-CVac administered pre-deployment to malaria-naive Indonesian soldiers assigned to temporary duties in a high malaria transmission area. We describe the manifold challenges of enrolling and immunizing 345 soldier participants at their home base in western Indonesia before their nearly 6,000-km voyage to eastern Indonesia, where they are being monitored for incident P. falciparum and Plasmodium vivax malaria cases during 9 months of exposure. The unique regulatory, ethical, and operational complexities of this trial demonstrate the importance of thorough planning, frequent communication, and close follow-up with stakeholders. Effective engagement with the military community and the ability to adapt to unanticipated events have proven key to the success of this trial.
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Affiliation(s)
| | - Krisin Chand
- Oxford University Clinical Research Unit Indonesia, Jakarta, Indonesia
| | - Rizka Fahmia
- Oxford University Clinical Research Unit Indonesia, Jakarta, Indonesia
| | - Mutia Rahardjani
- Oxford University Clinical Research Unit Indonesia, Jakarta, Indonesia
| | - Fitria Wulandari
- Oxford University Clinical Research Unit Indonesia, Jakarta, Indonesia
| | - Decy Subekti
- Oxford University Clinical Research Unit Indonesia, Jakarta, Indonesia
| | - Rintis Noviyanti
- Eijkman Research Center for Molecular Biology, National Research & Innovation Agency, Cibinong, West Java, Indonesia
- EXEINS Health Initiative, Jakarta, Indonesia
| | - Amin Soebandrio
- Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Noch T. Mallisa
- Presidential Staff Office, Republic of Indonesia, Jakarta, Indonesia
| | | | - Waras Budiman
- Muhammadiyah University, Surabaya, East Java, Indonesia
| | | | - Yogi Ertanto
- Army Medical Center, Army of the Republic of Indonesia, Jakarta, Indonesia
| | | | | | | | | | | | | | | | | | - Lenny L. Ekawati
- Oxford University Clinical Research Unit Indonesia, Jakarta, Indonesia
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - J. Kevin Baird
- Oxford University Clinical Research Unit Indonesia, Jakarta, Indonesia
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Erni J. Nelwan
- Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Division of Tropical Medicine and Infectious Disease, Department of Internal Medicine, Cipto Mangunkusumo Hospital, Jakarta, Indonesia
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Billingsley PF, Richie TL, Abdulla S, Ondo'o Ayekaba M, Daubenberger CA, Garcia GA, Hoffman SL. A paradigm for Africa-centric vaccine development in Equatorial Guinea. Trends Parasitol 2024; 40:362-366. [PMID: 38582683 DOI: 10.1016/j.pt.2024.03.005] [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: 12/31/2023] [Revised: 02/26/2024] [Accepted: 03/12/2024] [Indexed: 04/08/2024]
Abstract
The Equatorial Guinea Malaria Vaccine Initiative (EGMVI) highlights how long-term African government and international energy industry investment, plus novel partnerships, can enable clinical development of vaccines in Africa, for Africa. We review achievements and challenges of this pioneering, award-winning, public-private partnership which offers a model for future Africa-centric clinical research and development (R&D).
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Affiliation(s)
| | - Thomas L Richie
- Sanaria Inc., 9800 Medical Center Drive, Rockville, MD 20850, USA
| | - Salim Abdulla
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Mitoha Ondo'o Ayekaba
- Ministry of Health and Social Welfare, Government of the Republic of Equatorial Guinea, Malabo, Bioko Norte, Equatorial Guinea
| | - Claudia A Daubenberger
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123 Allschwil, Switzerland; University of Basel, Peterplatz 1, 4001 Basel, Switzerland
| | - Guíllermo A Garcia
- MCD Global Health, 8403 Colesville Rd, Suite 320, Silver Spring, MD 20910, USA
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8
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Thomson-Luque R, Stabler TC, Fürle K, Silva JC, Daubenberger C. Plasmodium falciparum merozoite surface protein 1 as asexual blood stage malaria vaccine candidate. Expert Rev Vaccines 2024; 23:160-173. [PMID: 38100310 DOI: 10.1080/14760584.2023.2295430] [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: 09/25/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023]
Abstract
INTRODUCTION Malaria represents a public health challenge in tropical and subtropical regions, and currently deployed control strategies are likely insufficient to drive elimination of malaria. Development and improvement of malaria vaccines might be key to reduce disease burden. Vaccines targeting asexual blood stages of the parasite have shown limited efficacy when studied in human trials conducted over the past decades. AREAS COVERED Vaccine candidates based on the merozoite surface protein 1 (MSP1) were initially envisioned as one of the most promising approaches to provide immune protection against asexual blood-stage malaria. Successful immunization studies in monkey involved the use of the full-length MSP1 (MSP1FL) as vaccine construct. Vaccines using MSP1FL for immunization have the potential benefit of including numerous conserved B-cell and T-cell epitopes. This could result in improved parasite strain-transcending, protective immunity in the field. We review outcomes of clinical trials that utilized a variety of MSP1 constructs and formulations, including MSP1FL, either alone or in combination with other antigens, in both animal models and humans. EXPERT OPINION Novel approaches to analyze breadth and magnitude of effector functions of MSP1-targeting antibodies in volunteers undergoing experimental vaccination and controlled human malaria infection will help to define correlates of protective immunity.
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Affiliation(s)
- Richard Thomson-Luque
- Centre for Infectious Diseases-Parasitology, Heidelberg University Hospital, Heidelberg, Germany
- Sumaya-Biotech GmbH & Co. KG Heidelberg, Germany
| | - Thomas C Stabler
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
- University of Basel Basel, Switzerland
- Swiss Tropical and Public Health Institute Allschwil, Switzerland
| | - Kristin Fürle
- Centre for Infectious Diseases-Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Joana C Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisboa (GHTM IHMT, UNL), Lisbon, Portugal
| | - Claudia Daubenberger
- University of Basel Basel, Switzerland
- Swiss Tropical and Public Health Institute Allschwil, Switzerland
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9
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Hammershaimb EA, Berry AA. Pre-erythrocytic malaria vaccines: RTS,S, R21, and beyond. Expert Rev Vaccines 2024; 23:49-52. [PMID: 38095048 DOI: 10.1080/14760584.2023.2292204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 12/04/2023] [Indexed: 12/18/2023]
Affiliation(s)
- Elizabeth Adrianne Hammershaimb
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Andrea A Berry
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, USA
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Zhang X, Li Q, Zhou Q, Li Y, Li J, Jin L, Li S, Cai J, Chen G, Hu G, Qian J. Determine the enzymatic kinetic characteristics of CYP3A4 variants utilizing artemether-lumefantrine. Food Chem Toxicol 2023; 181:114065. [PMID: 37769895 DOI: 10.1016/j.fct.2023.114065] [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: 08/05/2023] [Revised: 09/16/2023] [Accepted: 09/25/2023] [Indexed: 10/03/2023]
Abstract
Artemether-lumefantrine is an artemisinin-based combination therapy for the treatment of malaria, which are primarily metabolized by cytochrome P450 3A4. Therapeutic difference caused by gene polymorphisms of CYP3A4 may lead to uncertain adverse side effects or treatment failure. The aim of this study was to evaluate the effect of CYP3A4 gene polymorphism on artemether-lumefantrine metabolism in vitro. Enzyme kinetics assay was performed using recombinant human CYP3A4 cell microsomes. The analytes, dihydroartimisinin and desbutyl-lumefantrine, were detected by ultra-performance liquid chromatography tandem mass spectrometry. The results demonstrated that compared to CYP3A4.1, the intrinsic clearance of CYP3A4.4, 5, 9, 16, 18, 23, 24, 28, 31-34 significantly reduced for artemether (58.5%-93.3%), and CYP3A4.17 almost loss catalytic activity. Simultaneously, CYP3A4.5, 14, 17, 24 for lumefantrine were decreased by 56.1%-99.6%, and CYP3A4.11, 15, 18, 19, 23, 28, 29, 31-34 for lumefantrine was increased by 51.7%-296%. The variation in clearance rate indicated by molecular docking could be attributed to the disparity in the binding affinity of artemether and lumefantrine with CYP3A4. The data presented here have enriched our understanding of the effect of CYP3A4 gene polymorphism on artemether-lumefantrine metabolizing. These findings serve as a valuable reference and provide insights for guiding the treatment strategy involving artemether-lumefantrine.
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Affiliation(s)
- Xiaodan Zhang
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Qingqing Li
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Quan Zhou
- The Laboratory of Clinical Pharmacy, The Sixth Affiliated Hospital of Wenzhou Medical University, Lishui People's Hospital, Lishui, Zhejiang, PR China
| | - Yunxuan Li
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Junwei Li
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Lehao Jin
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Sen Li
- School of Basic Medicine, Wenzhou Medical University, Wenzhou, 325035, PR China
| | - Jianping Cai
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Beijing Hospital, National Center of Gerontology, National Health Commission, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, PR China.
| | - Gaozhi Chen
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, PR China.
| | - Guoxin Hu
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, PR China.
| | - Jianchang Qian
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, PR China.
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Wilson RA. Models of Protective Immunity against Schistosomes: Implications for Vaccine Development. Pathogens 2023; 12:1215. [PMID: 37887731 PMCID: PMC10610196 DOI: 10.3390/pathogens12101215] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 09/26/2023] [Accepted: 10/01/2023] [Indexed: 10/28/2023] Open
Abstract
After many decades of research, a schistosome vaccine still looks to be a distant prospect. These helminths can live in the human bloodstream for years, even decades, surrounded by and feeding on the components of the immune response they provoke. The original idea of a vaccine based on the killing of invading cercariae in the skin has proven to be illusory. There has also been a realisation that even if humans develop some protection against infection over a protracted period, it very likely involves IgE-mediated responses that cannot provide the basis for a vaccine. However, it has also become clear that both invasive migrating larvae and adult worms must expose proteins and release secretions into the host environment as part of their normal biological activities. The application of modern 'omics approaches means that we now have a much better idea of the identity of these potential immune targets. This review looks at three animal models in which acquired immunity has been demonstrated and asks whether the mechanisms might inform our vaccine strategies to achieve protection in model hosts and humans. Eliciting responses, either humoral or cellular, that can persist for many months is a challenge. Arming of the lungs with effector T cells, as occurs in mice exposed to the radiation-attenuated cercarial vaccine, is one avenue. Generating IgG antibody titres that reach levels at which they can exert sustained immune pressure to cause worm elimination, as occurs in rhesus macaques, is another. The induction of memory cell populations that can detect trickle invasions of larval stages remains to be explored. One promising approach is the analysis of protective antibodies using high-density peptide arrays of target proteins to identify reactive regions. These can be combined in multi-epitope constructs to immunise a host against many targets simultaneously and cheaply.
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Affiliation(s)
- R Alan Wilson
- Department of Biology and Biomedical Research Institute, University of York, York YO10 5DD, UK;
- Programa de Pós Graduação em, Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto 35402-136 , Brazil
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