The Advanced Development Pathway of the RTS,S/AS01 Vaccine

Following successful phase 1 and 2 trials, RTS,S/AS01 was evaluated in a large phase 3 trial in 7 African countries in which 8922 young children and 6537 infants were enrolled and followed for a median of 48 and 38 months, respectively. The vaccine efficacy against uncomplicated malaria in children was 28% without booster and 36% with booster. The vaccine received the approval of the European Medical Agency in 2015, but two WHO expert committees requested more data before the programmatic use of RTS,S/AS01 in African children can be recommended. To provide such data, a very large, cluster randomized trial is currently in progress in three African countries. The integration of RTS,S/AS01 in national childhood vaccination programs will benefit the individual vaccinated child but is unlikely to make an impact on malaria transmission. Mass vaccination campaigns that include all age groups over short periods are more likely to harness the short but high protection afforded by RTS,S/AS01.