A first-in-human, open-label, non-randomized, multi-center, dose escalation Phase I/IIa clinical trial evaluated the safety, immunogenicity, and efficacy of the RH5.1/AS01B vaccine against blood-stage malaria. The study involved healthy, malaria-naive adults aged 18 to 45, demonstrating the vaccine's potential to reduce parasite multiplication rate and its safety profile across different doses.