Understanding protective immune mechanisms induced by malaria vaccines in the context of clinical trials.

Abstract

Malaria is one of the world's most important diseases, and an effective, licensed vaccine would be a major public health tool. There is currently a surge in efforts to develop malaria vaccines, and many candidates are entering and progressing through clinical trials. However, inadequate understanding of host immunity, gaps in knowledge of parasite biology and the lack of surrogate markers of protection have hindered rational vaccine development and led to failure to control malaria. A greater understanding of naturally acquired immunity would certainly help guide vaccine development and deployment. The research tools at our disposal are greater and more superior than before, and the growing capacity to perform immunological assays in the field brings new possibilities for investigating vaccine-induced immunity and immune correlates of protection within clinical trials. The malaria vaccine community needs to learn from the TB and HIV vaccine communities, who have developed and optimized multi-parameter immunological assays, some of which are amenable for studies conducted in African children. The best strategy is to take advantage of large clinical trials in endemic countries to better understand immunity to malaria, vaccine take and identify surrogates of protection.