KIU Publications

Malaria remains a leading cause of childhood mortality in sub-Saharan Africa, with Plasmodium falciparum responsible for over 400,000 deaths annually, predominantly in children under five years of age. This review evaluated the long-term efficacy and protection dynamics of the RTS, S/AS01 vaccine in pediatric populations across endemic regions of sub-Saharan Africa. A comprehensive literature search was conducted using PubMed, Embase, and Cochrane databases from 2011 to 2024, focusing on Phase III clinical trials, post-implementation surveillance studies, and immunological assessments of RTS, S vaccine performance. Analysis of pivotal clinical trial data and real-world implementation studies demonstrated that RTS, S provides modest but significant protection against clinical malaria in children aged 5-17 months, with vaccine efficacy ranging from 36-50% in the first-year postvaccination, declining to 16-26% by year four. Long-term follow-up studies revealed substantial waning of protective immunity, with antibody titers against the circumsporozoite protein declining rapidly within 12-18 months of vaccination. Post-marketing surveillance from Ghana, Kenya, and Malawi indicated real-world effectiveness of 1322% against severe malaria hospitalizations, with optimal protection observed when RTS, S is combined with insecticide-treated nets and seasonal chemoprevention. The vaccine demonstrated acceptable safety profiles but requires strategic deployment in high-transmission settings to maximize population-level impact. RTS, S represents a significant advancement in malaria prevention but exhibits limited long-term protective immunity necessitating improved second-generation vaccines.