Seasonal mass vaccination with R21/Matrix-M for malaria elimination (SERVAL): protocol of the cluster randomised trial
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Introduction
Progress in malaria control has stalled since 2015, highlighting the need for new control tools. The R21/Matrix-M (R21) malaria vaccine, a pre-erythrocytic vaccine recently approved by WHO for small children, may be one of these tools. This trial aims to assess whether seasonal mass vaccination with R21 reduces malaria transmission in The Gambia and Burkina Faso, two countries at the extreme of the transmission spectrum.
Methods
This is a multi-centre open cluster-randomised controlled trial to assess the impact of mass vaccination with R21 on malaria transmission and morbidity. The trial will be implemented in eastern Gambia (low to moderate transmission) and Central Burkina Faso (intense transmission). Thirty medium-sized villages in The Gambia and 24 in Burkina Faso will be randomised (1:1) to either intervention or control arm. All eligible residents in intervention villages will receive R21 vaccinations in three-monthly rounds, from May to July 2024, prior to the malaria transmission season. A booster vaccine dose will be administered the following year, in June 2025. The primary outcome is malaria prevalence at peak transmission (November 2024). Secondary outcomes include safety and tolerability, incidence of clinical malaria, vaccination coverage and community acceptability, cost and cost-effectiveness of the intervention.
Discussion
This is the first trial on seasonal mass vaccination aiming at reducing malaria transmission. Strengths of the study include its design as an adequately powered cluster-randomised trial and the inclusion of study sites with differing transmission intensity which will also provide safety and efficacy data for different age groups. Key challenges remain vaccine hesitancy and vaccination coverage. If successful, R21 seasonal mass vaccination will be an innovative intervention to accelerate malaria elimination efforts and reach the goal set in the Global Technical Strategy for malaria 2016–2030.
Trial registration
Clinical trials.gov, NCT06578572. Registered on 27 March 2024.
Peer Review reports
Progress in malaria control has stalled since 2015, highlighting the need for new control tools. The R21/Matrix-M (R21) malaria vaccine, a pre-erythrocytic vaccine recently approved by WHO for small children, may be one of these tools. This trial aims to assess whether seasonal mass vaccination with R21 reduces malaria transmission in The Gambia and Burkina Faso, two countries at the extreme of the transmission spectrum.
Methods
This is a multi-centre open cluster-randomised controlled trial to assess the impact of mass vaccination with R21 on malaria transmission and morbidity. The trial will be implemented in eastern Gambia (low to moderate transmission) and Central Burkina Faso (intense transmission). Thirty medium-sized villages in The Gambia and 24 in Burkina Faso will be randomised (1:1) to either intervention or control arm. All eligible residents in intervention villages will receive R21 vaccinations in three-monthly rounds, from May to July 2024, prior to the malaria transmission season. A booster vaccine dose will be administered the following year, in June 2025. The primary outcome is malaria prevalence at peak transmission (November 2024). Secondary outcomes include safety and tolerability, incidence of clinical malaria, vaccination coverage and community acceptability, cost and cost-effectiveness of the intervention.
Discussion
This is the first trial on seasonal mass vaccination aiming at reducing malaria transmission. Strengths of the study include its design as an adequately powered cluster-randomised trial and the inclusion of study sites with differing transmission intensity which will also provide safety and efficacy data for different age groups. Key challenges remain vaccine hesitancy and vaccination coverage. If successful, R21 seasonal mass vaccination will be an innovative intervention to accelerate malaria elimination efforts and reach the goal set in the Global Technical Strategy for malaria 2016–2030.
Trial registration
Clinical trials.gov, NCT06578572. Registered on 27 March 2024.
Peer Review reports
Date Issued
2025-09-29
Date Acceptance
2025-08-08
Citation
Trials, 2025, 26
ISSN
1745-6215
Publisher
BMC
Journal / Book Title
Trials
Volume
26
Copyright Statement
© The Author(s) 2025. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/41024138
PII: 10.1186/s13063-025-09048-6
Subjects
Burkina Faso
Cluster randomised trial
Malaria
R21/Matrix-M
Seasonal mass vaccination
The Gambia
Humans
Malaria Vaccines
Gambia
Seasons
Burkina Faso
Multicenter Studies as Topic
Randomized Controlled Trials as Topic
Malaria
Mass Vaccination
Infant
Child, Preschool
Publication Status
Published
Coverage Spatial
England
Article Number
382
Date Publish Online
2025-09-29