Abstract

Malaria remained a major global health burden, with Plasmodium falciparum causing significant morbidity and 
mortality, particularly among children in sub-Saharan Africa. The RTS, S/AS01 vaccine represents the first licensed 
malaria vaccine, targeting the circumsporozoite protein of the parasite's pre-erythrocytic stage. This review 
critically examined the efficacy profile of RTS,S/AS01, evaluated implementation challenges encountered during 
pilot programs, and assessed the vaccine's broader public health impact in endemic regions. A comprehensive 
literature search was conducted across PubMed, Scopus, and clinical trial registries, selecting peer-reviewed articles, 
systematic reviews, and implementation reports published between 2011 and 2025. Phase III trials demonstrated 
modest efficacy, with approximately 32% reduction in clinical malaria episodes among children aged 5 to 17 months 
over four years when administered in four doses. Pilot implementation programs in Ghana, Kenya, and Malawi 
revealed significant operational challenges, including maintaining cold chain integrity, achieving adequate coverage 
across four-dose schedules, and integrating delivery with existing immunization programs. Despite moderate 
efficacy, mathematical modeling indicates that RTS, S/AS01 deployment in high-transmission settings can avert 
substantial numbers of clinical cases and deaths when combined with existing vector control and chemoprevention 
strategies. Cost-effectiveness analyses suggested favorable outcomes in areas with persistent high transmission. 
Antibody responses wane substantially within 12 months post vaccination, raising questions about optimal booster 
timing and long-term protection. RTS, S/AS01 represented a significant milestone in malaria control, offering 
partial protection that complements existing interventions. Ongoing research must address immunological gaps, 
optimize delivery strategies, and monitor real-world effectiveness to maximize public health benefit.