Escaping the immune system: How the malaria parasite makes vaccine development a challenge.

Malaria is a major cause of morbidity and mortality. Immunity is acquired but is suboptimal, being slow to develop and incomplete. An inadequate understanding of natural immunity, host-parasite interactions, and a lack of reliable immune correlates of protection that could predict vaccine efficacy in the field have hindered development of a vaccine. With data from Phase III trials indicating that the leading malaria vaccine candidate, RTS,S, has limited efficacy, it is necessary to reconsider approaches to the development of a vaccine capable of inducing long-lived protection.