tinnitus this is from the Gates website, you really should read it, it's good stuff (and he is doing a wonderful job)
Vaccines
An effective vaccine could provide a powerful tool against malaria, but developing one will take sustained scientific effort over many years. In recent Phase III clinical trials, the RTS,S malaria vaccine had lower-than-desired efficacy, but the data demonstrated that it is possible to vaccinate against a parasite—an important advance.
Beyond the current vaccine candidates that could play an important role in reducing malaria in various target groups, successful efforts to eradicate malaria will ultimately require more efficacious second-generation vaccines that can block transmission across entire populations at risk. The process of vaccine development is currently slowed by lack of knowledge of the mechanisms of immunity.
We invest in efforts to develop vaccines that can interrupt malaria transmission, including a second-generation vaccine or new vaccines based on transmission-blocking antigens. We also support research that can guide more efficient vaccine development.
