Towards the development of the ideal malaria vaccine. A decade of progress in a difficult field.

Malaria remains one of the world's most serious diseases, affecting the lives of up to 500 million people. The rapid development of drug resistance enhances the need for the development of a vaccine. Since the first cloning of malaria proteins early in the last decade, there have been a number of "subunit" vaccine trials involving humans and monkeys. During this time, our understanding of the basic immunobiology of malaria has increased; different immune mechanisms are required to combat the different stages in the life cycle of the parasite, and the future vaccine will have to stimulate these different effector mechanisms. There has been steady progress over the last decade toward an effective vaccine, but a great deal of further effort is still required.