Impact of climate and acquired immunity on malaria burden in Senegal and The Gambia: an agent-based modeling study

Immunity against malaria is acquired slowly and incompletely through repeated infections, with individuals having varying levels of protection based on their exposure history. Standard epidemiological models represent immunity as a population-average trait, which can lead to incorrect estimates of malaria prevalence by age and overall disease burden. The research team developed VECTRI-ABM, a model combining climate factors with individual-level representation of human population and immunity. The model was calibrated using data from Senegal from 1990 to 2003 and tested against data from Senegal and The Gambia. Results showed that the simplified immunity approach underestimates clinical malaria prevalence in children, particularly in high-transmission areas, and overestimates asymptomatic reservoirs in adults. The error introduced by the simplified approach is climate-dependent and less significant in populations older than 15 years.