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Cairns M, Barry A, Zongo I, Sagara I, Yerbanga SR, Diarra M, Zoungrana C, Issiaka D, Sienou AA, Tapily A, Sanogo K, Kaya M, Traore S, Diarra K, Yalcouye H, Sidibe Y, Haro A, Thera I, Snell P, Grant J, Tinto H, Milligan P, Chandramohan D, Greenwood B, Dicko A, Ouedraogo JB. The duration of protection against clinical malaria provided by the combination of seasonal RTS,S/AS01 E vaccination and seasonal malaria chemoprevention versus either intervention given alone. BMC Med 2022; 20:352. [PMID: 36203149 PMCID: PMC9540742 DOI: 10.1186/s12916-022-02536-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/18/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A recent trial of 5920 children in Burkina Faso and Mali showed that the combination of seasonal vaccination with the RTS,S/AS01E malaria vaccine (primary series and two seasonal boosters) and seasonal malaria chemoprevention (four monthly cycles per year) was markedly more effective than either intervention given alone in preventing clinical malaria, severe malaria, and deaths from malaria. METHODS In order to help optimise the timing of these two interventions, trial data were reanalysed to estimate the duration of protection against clinical malaria provided by RTS,S/AS01E when deployed seasonally, by comparing the group who received the combination of SMC and RTS,S/AS01E with the group who received SMC alone. The duration of protection from SMC was also estimated comparing the combined intervention group with the group who received RTS,S/AS01E alone. Three methods were used: Piecewise Cox regression, Flexible parametric survival models and Smoothed Schoenfeld residuals from Cox models, stratifying on the study area and using robust standard errors to control for within-child clustering of multiple episodes. RESULTS The overall protective efficacy from RTS,S/AS01E over 6 months was at least 60% following the primary series and the two seasonal booster doses and remained at a high level over the full malaria transmission season. Beyond 6 months, protective efficacy appeared to wane more rapidly, but the uncertainty around the estimates increases due to the lower number of cases during this period (coinciding with the onset of the dry season). Protection from SMC exceeded 90% in the first 2-3 weeks post-administration after several cycles, but was not 100%, even immediately post-administration. Efficacy begins to decline from approximately day 21 and then declines more sharply after day 28, indicating the importance of preserving the delivery interval for SMC cycles at a maximum of four weeks. CONCLUSIONS The efficacy of both interventions was highest immediately post-administration. Understanding differences between these interventions in their peak efficacy and how rapidly efficacy declines over time will help to optimise the scheduling of SMC, malaria vaccination and the combination in areas of seasonal transmission with differing epidemiology, and using different vaccine delivery systems. TRIAL REGISTRATION The RTS,S-SMC trial in which these data were collected was registered at clinicaltrials.gov: NCT03143218.
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Affiliation(s)
- Matthew Cairns
- International Statistics and Epidemiology Group, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.
| | - Amadou Barry
- Malaria Research and Training Centre, Bamako, Mali
| | - Issaka Zongo
- Institut de Recherche en Sciences de la Santé, Bobo Dioulasso, Burkina Faso
| | | | - Serge R Yerbanga
- Institut de Recherche en Sciences de la Santé, Bobo Dioulasso, Burkina Faso
| | | | - Charles Zoungrana
- Institut de Recherche en Sciences de la Santé, Bobo Dioulasso, Burkina Faso
| | | | - Abdoul Aziz Sienou
- Institut de Recherche en Sciences de la Santé, Bobo Dioulasso, Burkina Faso
| | | | | | | | | | | | | | | | - Alassane Haro
- Institut de Recherche en Sciences de la Santé, Bobo Dioulasso, Burkina Faso
| | | | - Paul Snell
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Jane Grant
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Halidou Tinto
- Institut de Recherche en Sciences de la Santé, Bobo Dioulasso, Burkina Faso
| | - Paul Milligan
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Daniel Chandramohan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Brian Greenwood
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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Grant J, Sagara I, Zongo I, Cairns M, Yerbanga RS, Diarra M, Zoungrana C, Issiaka D, Nikièma F, Sompougdou F, Tapily A, Kaya M, Haro A, Sanogo K, Sienou AA, Traore S, Thera I, Yalcouye H, Kuepfer I, Snell P, Milligan P, Ockenhouse C, Ofori-Anyinam O, Tinto H, Djimde A, Chandramohan D, Greenwood B, Dicko A, Ouédraogo JB. Impact of seasonal RTS,S/AS01 E vaccination plus seasonal malaria chemoprevention on the nutritional status of children in Burkina Faso and Mali. Malar J 2022; 21:59. [PMID: 35193608 PMCID: PMC8864823 DOI: 10.1186/s12936-022-04077-x] [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: 11/08/2021] [Accepted: 02/06/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A recent trial in Burkina Faso and Mali showed that combining seasonal RTS,S/AS01E malaria vaccination with seasonal malaria chemoprevention (SMC) substantially reduced the incidence of uncomplicated and severe malaria in young children compared to either intervention alone. Given the possible negative effect of malaria on nutrition, the study investigated whether these children also experienced lower prevalence of acute and chronic malnutrition. METHODS In Burkina Faso and Mali 5920 children were randomized to receive either SMC alone, RTS,S/AS01E alone, or SMC combined with RTS,S/AS01E for three malaria transmission seasons (2017-2019). After each transmission season, anthropometric measurements were collected from all study children at a cross-sectional survey and used to derive nutritional status indicators, including the binary variables wasted and stunted (weight-for-height and height-for-age z-scores below - 2, respectively). Binary and continuous outcomes between treatment groups were compared by Poisson and linear regression. RESULTS In 2017, compared to SMC alone, the combined intervention reduced the prevalence of wasting by approximately 12% [prevalence ratio (PR) = 0.88 (95% CI 0.75, 1.03)], and approximately 21% in 2018 [PR = 0.79 (95% CI 0.62, 1.01)]. Point estimates were similar for comparisons with RTS,S/AS01E, but there was stronger evidence of a difference. There was at least a 30% reduction in the point estimates for the prevalence of severe wasting in the combined group compared to the other two groups in 2017 and 2018. There was no difference in the prevalence of moderate or severe wasting between the groups in 2019. The prevalence of stunting, low-MUAC-for-age or being underweight did not differ between groups for any of the three years. The prevalence of severe stunting was higher in the combined group compared to both other groups in 2018, and compared to RTS,S/AS01E alone in 2017; this observation does not have an obvious explanation and may be a chance finding. Overall, malnutrition was very common in this cohort, but declined over the study as the children became older. CONCLUSIONS Despite a high burden of malnutrition and malaria in the study populations, and a major reduction in the incidence of malaria in children receiving both interventions, this had only a modest impact on nutritional status. Therefore, other interventions are needed to reduce the high burden of malnutrition in these areas. TRIAL REGISTRATION https://www.clinicaltrials.gov/ct2/show/NCT03143218 , registered 8th May 2017.
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Affiliation(s)
- Jane Grant
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK.
| | - Issaka Sagara
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Issaka Zongo
- Institut de Recherche en Sciences de La Santé, Bobo-Dioulasso, Burkina Faso
| | - Matthew Cairns
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK
| | | | - Modibo Diarra
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Charles Zoungrana
- Institut de Recherche en Sciences de La Santé, Bobo-Dioulasso, Burkina Faso
| | - Djibrilla Issiaka
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Frédéric Nikièma
- Institut de Recherche en Sciences de La Santé, Bobo-Dioulasso, Burkina Faso
| | | | - Amadou Tapily
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Mahamadou Kaya
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Alassane Haro
- Institut de Recherche en Sciences de La Santé, Bobo-Dioulasso, Burkina Faso
| | - Koualy Sanogo
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Abdoul Aziz Sienou
- Institut de Recherche en Sciences de La Santé, Bobo-Dioulasso, Burkina Faso
| | - Seydou Traore
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Ismaila Thera
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Hama Yalcouye
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Irene Kuepfer
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK
| | - Paul Snell
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK
| | - Paul Milligan
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK
| | | | | | - Halidou Tinto
- Institut de Recherche en Sciences de La Santé, Bobo-Dioulasso, Burkina Faso
| | - Abdoulaye Djimde
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Daniel Chandramohan
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK
| | - Brian Greenwood
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK
| | - Alassane Dicko
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
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Greenwood B, Cairns M, Chaponda M, Chico RM, Dicko A, Ouedraogo JB, Phiri KS, Ter Kuile FO, Chandramohan D. Combining malaria vaccination with chemoprevention: a promising new approach to malaria control. Malar J 2021; 20:361. [PMID: 34488784 PMCID: PMC8419817 DOI: 10.1186/s12936-021-03888-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
Malaria control has stalled in a number of African countries and novel approaches to malaria control are needed for these areas. The encouraging results of a recent trial conducted in young children in Burkina Faso and Mali in which a combination of the RTS,S/AS01E malaria vaccine and seasonal malaria chemoprevention led to a substantial reduction in clinical cases of malaria, severe malaria, and malaria deaths compared with the administration of either intervention given alone suggests that there may be other epidemiological/clinical situations in which a combination of malaria vaccination and chemoprevention could be beneficial. Some of these potential opportunities are considered in this paper. These include combining vaccination with intermittent preventive treatment of malaria in infants, with intermittent preventive treatment of malaria in pregnancy (through vaccination of women of child-bearing age before or during pregnancy), or with post-discharge malaria chemoprevention in the management of children recently admitted to hospital with severe anaemia. Other potential uses of the combination are prevention of malaria in children at particular risk from the adverse effects of clinical malaria, such as those with sickle cell disease, and during the final stages of a malaria elimination programme when vaccination could be combined with repeated rounds of mass drug administration. The combination of a pre-erythrocytic stage malaria vaccine with an effective chemopreventive regimen could make a valuable contribution to malaria control and elimination in a variety of clinical or epidemiological situations, and the potential of this approach to malaria control needs to be explored.
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Affiliation(s)
| | - Matthew Cairns
- London School of Hygiene and Tropical Medicine, London, UK
| | | | | | - Alassane Dicko
- Malaria Research and Training Centre, University of Science, Techniques and Technology of Bamako, Bamako, Mali
| | | | - Kamija S Phiri
- School of Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
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Minassian AM, Silk SE, Barrett JR, Nielsen CM, Miura K, Diouf A, Loos C, Fallon JK, Michell AR, White MT, Edwards NJ, Poulton ID, Mitton CH, Payne RO, Marks M, Maxwell-Scott H, Querol-Rubiera A, Bisnauthsing K, Batra R, Ogrina T, Brendish NJ, Themistocleous Y, Rawlinson TA, Ellis KJ, Quinkert D, Baker M, Lopez Ramon R, Ramos Lopez F, Barfod L, Folegatti PM, Silman D, Datoo M, Taylor IJ, Jin J, Pulido D, Douglas AD, de Jongh WA, Smith R, Berrie E, Noe AR, Diggs CL, Soisson LA, Ashfield R, Faust SN, Goodman AL, Lawrie AM, Nugent FL, Alter G, Long CA, Draper SJ. Reduced blood-stage malaria growth and immune correlates in humans following RH5 vaccination. MED 2021; 2:701-719.e19. [PMID: 34223402 PMCID: PMC8240500 DOI: 10.1016/j.medj.2021.03.014] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 02/19/2021] [Accepted: 03/25/2021] [Indexed: 12/27/2022]
Abstract
BACKGROUND Development of an effective vaccine against the pathogenic blood-stage infection of human malaria has proved challenging, and no candidate vaccine has affected blood-stage parasitemia following controlled human malaria infection (CHMI) with blood-stage Plasmodium falciparum. METHODS We undertook a phase I/IIa clinical trial in healthy adults in the United Kingdom of the RH5.1 recombinant protein vaccine, targeting the P. falciparum reticulocyte-binding protein homolog 5 (RH5), formulated in AS01B adjuvant. We assessed safety, immunogenicity, and efficacy against blood-stage CHMI. Trial registered at ClinicalTrials.gov, NCT02927145. FINDINGS The RH5.1/AS01B formulation was administered using a range of RH5.1 protein vaccine doses (2, 10, and 50 μg) and was found to be safe and well tolerated. A regimen using a delayed and fractional third dose, in contrast to three doses given at monthly intervals, led to significantly improved antibody response longevity over ∼2 years of follow-up. Following primary and secondary CHMI of vaccinees with blood-stage P. falciparum, a significant reduction in parasite growth rate was observed, defining a milestone for the blood-stage malaria vaccine field. We show that growth inhibition activity measured in vitro using purified immunoglobulin G (IgG) antibody strongly correlates with in vivo reduction of the parasite growth rate and also identify other antibody feature sets by systems serology, including the plasma anti-RH5 IgA1 response, that are associated with challenge outcome. CONCLUSIONS Our data provide a new framework to guide rational design and delivery of next-generation vaccines to protect against malaria disease. FUNDING This study was supported by USAID, UK MRC, Wellcome Trust, NIAID, and the NIHR Oxford-BRC.
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Affiliation(s)
| | - Sarah E. Silk
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | | | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Carolin Loos
- The Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Ashlin R. Michell
- The Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Michael T. White
- Department of Parasites and Insect Vectors, Institut Pasteur, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - Nick J. Edwards
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Ian D. Poulton
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Celia H. Mitton
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Ruth O. Payne
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Michael Marks
- Centre for Clinical Infection and Diagnostics Research, King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK
| | - Hector Maxwell-Scott
- Centre for Clinical Infection and Diagnostics Research, King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK
| | - Antonio Querol-Rubiera
- Centre for Clinical Infection and Diagnostics Research, King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK
| | - Karen Bisnauthsing
- Centre for Clinical Infection and Diagnostics Research, King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK
| | - Rahul Batra
- Centre for Clinical Infection and Diagnostics Research, King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK
| | - Tatiana Ogrina
- NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Nathan J. Brendish
- NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | | | | | | | - Doris Quinkert
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Megan Baker
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | | | - Lea Barfod
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Daniel Silman
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Mehreen Datoo
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Iona J. Taylor
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Jing Jin
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - David Pulido
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Willem A. de Jongh
- ExpreSion Biotechnologies, SCION-DTU Science Park, Agern Allé 1, Hørsholm 2970, Denmark
| | - Robert Smith
- Clinical BioManufacturing Facility, University of Oxford, Oxford OX3 7JT, UK
| | - Eleanor Berrie
- Clinical BioManufacturing Facility, University of Oxford, Oxford OX3 7JT, UK
| | | | | | | | | | - Saul N. Faust
- NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Anna L. Goodman
- Centre for Clinical Infection and Diagnostics Research, King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK
| | | | - Fay L. Nugent
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Galit Alter
- The Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Carole A. Long
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Simon J. Draper
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
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5
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Datoo MS, Natama MH, Somé A, Traoré O, Rouamba T, Bellamy D, Yameogo P, Valia D, Tegneri M, Ouedraogo F, Soma R, Sawadogo S, Sorgho F, Derra K, Rouamba E, Orindi B, Ramos Lopez F, Flaxman A, Cappuccini F, Kailath R, Elias S, Mukhopadhyay E, Noe A, Cairns M, Lawrie A, Roberts R, Valéa I, Sorgho H, Williams N, Glenn G, Fries L, Reimer J, Ewer KJ, Shaligram U, Hill AVS, Tinto H. Efficacy of a low-dose candidate malaria vaccine, R21 in adjuvant Matrix-M, with seasonal administration to children in Burkina Faso: a randomised controlled trial. Lancet 2021; 397:1809-1818. [PMID: 33964223 PMCID: PMC8121760 DOI: 10.1016/s0140-6736(21)00943-0] [Citation(s) in RCA: 200] [Impact Index Per Article: 66.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 04/16/2021] [Accepted: 04/17/2021] [Indexed: 01/03/2023]
Abstract
BACKGROUND Stalled progress in controlling Plasmodium falciparum malaria highlights the need for an effective and deployable vaccine. RTS,S/AS01, the most effective malaria vaccine candidate to date, demonstrated 56% efficacy over 12 months in African children. We therefore assessed a new candidate vaccine for safety and efficacy. METHODS In this double-blind, randomised, controlled, phase 2b trial, the low-dose circumsporozoite protein-based vaccine R21, with two different doses of adjuvant Matrix-M (MM), was given to children aged 5-17 months in Nanoro, Burkina Faso-a highly seasonal malaria transmission setting. Three vaccinations were administered at 4-week intervals before the malaria season, with a fourth dose 1 year later. All vaccines were administered intramuscularly into the thigh. Group 1 received 5 μg R21 plus 25 μg MM, group 2 received 5 μg R21 plus 50 μg MM, and group 3, the control group, received rabies vaccinations. Children were randomly assigned (1:1:1) to groups 1-3. An independent statistician generated a random allocation list, using block randomisation with variable block sizes, which was used to assign participants. Participants, their families, and the local study team were all masked to group allocation. Only the pharmacists preparing the vaccine were unmasked to group allocation. Vaccine safety, immunogenicity, and efficacy were evaluated over 1 year. The primary objective assessed protective efficacy of R21 plus MM (R21/MM) from 14 days after the third vaccination to 6 months. Primary analyses of vaccine efficacy were based on a modified intention-to-treat population, which included all participants who received three vaccinations, allowing for inclusion of participants who received the wrong vaccine at any timepoint. This trial is registered with ClinicalTrials.gov, NCT03896724. FINDINGS From May 7 to June 13, 2019, 498 children aged 5-17 months were screened, and 48 were excluded. 450 children were enrolled and received at least one vaccination. 150 children were allocated to group 1, 150 children were allocated to group 2, and 150 children were allocated to group 3. The final vaccination of the primary series was administered on Aug 7, 2019. R21/MM had a favourable safety profile and was well tolerated. The majority of adverse events were mild, with the most common event being fever. None of the seven serious adverse events were attributed to the vaccine. At the 6-month primary efficacy analysis, 43 (29%) of 146 participants in group 1, 38 (26%) of 146 participants in group 2, and 105 (71%) of 147 participants in group 3 developed clinical malaria. Vaccine efficacy was 74% (95% CI 63-82) in group 1 and 77% (67-84) in group 2 at 6 months. At 1 year, vaccine efficacy remained high, at 77% (67-84) in group 1. Participants vaccinated with R21/MM showed high titres of malaria-specific anti-Asn-Ala-Asn-Pro (NANP) antibodies 28 days after the third vaccination, which were almost doubled with the higher adjuvant dose. Titres waned but were boosted to levels similar to peak titres after the primary series of vaccinations after a fourth dose administered 1 year later. INTERPRETATION R21/MM appears safe and very immunogenic in African children, and shows promising high-level efficacy. FUNDING The European & Developing Countries Clinical Trials Partnership, Wellcome Trust, and National Institute for Health Research Oxford Biomedical Research Centre.
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Affiliation(s)
- Mehreen S Datoo
- Centre for Clinical Vaccinology and Tropical Medicine, The Jenner Institute, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Magloire H Natama
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Athanase Somé
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Ousmane Traoré
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Toussaint Rouamba
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Duncan Bellamy
- The Jenner Institute Laboratories, University of Oxford, UK
| | - Prisca Yameogo
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Daniel Valia
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Moubarak Tegneri
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Florence Ouedraogo
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Rachidatou Soma
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Seydou Sawadogo
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Faizatou Sorgho
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Karim Derra
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Eli Rouamba
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | | | - Fernando Ramos Lopez
- Centre for Clinical Vaccinology and Tropical Medicine, The Jenner Institute, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Amy Flaxman
- The Jenner Institute Laboratories, University of Oxford, UK
| | | | - Reshma Kailath
- The Jenner Institute Laboratories, University of Oxford, UK
| | - Sean Elias
- The Jenner Institute Laboratories, University of Oxford, UK
| | | | - Andres Noe
- The Jenner Institute Laboratories, University of Oxford, UK
| | - Matthew Cairns
- London School of Hygiene & Tropical Medicine, London, UK
| | - Alison Lawrie
- Centre for Clinical Vaccinology and Tropical Medicine, The Jenner Institute, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Rachel Roberts
- Centre for Clinical Vaccinology and Tropical Medicine, The Jenner Institute, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Innocent Valéa
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Hermann Sorgho
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | | | | | | | | | - Katie J Ewer
- The Jenner Institute Laboratories, University of Oxford, UK
| | | | - Adrian V S Hill
- Centre for Clinical Vaccinology and Tropical Medicine, The Jenner Institute, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, UK; The Jenner Institute Laboratories, University of Oxford, UK.
| | - Halidou Tinto
- Unité de Recherche Clinique de Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso.
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