Determining optimal approach to deliver malaria vaccine in seasonal transmission areas through Phase 4 implementation research

ongoing

Seasonal malaria chemoprevention (SMC), the administration of sulphadoxine-pyrimethamine and amodiaquine (SP+AQ), during the peak period of malaria risk has proved to be a highly effective malaria control measure in areas where transmission of malaria is highly seasonal; SMC was administered to 45 million children in 2021. Still, malaria remains the main cause of hospital admissions among young children in many parts of the Sahel and sub-Sahel and additional control measures are needed to protect children. The malaria vaccines RTS,S/AS01E, and R21/Matrix, provide a high level of protection during the first few months after a primary series of vaccination, or after a booster dose, but efficacy wanes progressively during the following months and years. Thus, in areas with seasonal malaria transmission, one potential use for these vaccines, which provide a high but relatively short period of protection, is administration of an annual booster dose given prior to the malaria transmission season in children who have received three priming doses of the vaccine in the first year of life. However, there is a debate about the best approach to delivery of the booster doses and the main objectives of this study are to determine whether annual booster doses of RTSS,AS01E vaccine administered pre-transmission season through a mass campaign will achieve better coverage and higher impact on the incidence of malaria than pre-transmission booster doses delivered by an EPI programme at vaccination centres. This will be a pragmatic implementation study involving two cohorts of children. Two districts that have comparable malaria epidemiology, social structure, coverage of EPI vaccines, and access to treatment will be identified in both Mali and in Guinea from the list of districts that are selected for roll out of RTS,S/ASO1E vaccine by the Ministry of Health. This project will provide important information on the optimum delivery which could save many lives.