Long-term follow-up of a phase II study from KEMRI-Wellcome Trust Research Programme and Oxford University researchers in Kenya shows that the efficacy of a malaria vaccine candidate, RTS,S, wanes over time and varies with exposure to the malaria parasite.
The findings will help to inform which populations are likely to benefit most from the vaccine candidate. They also have important implications for the design of future clinical trials of this and other vaccine candidates and highlight the importance of long-term follow-up studies for assessing vaccine efficacy.