The new information and advances in malaria in the last few years, especially at the immunological and cellular level, have truly been impressive. Consequently, shifting emphasis to this area of research action has stirred expectations of new initiatives for an attack on malaria by immunologic methods. Three of the four presentations that follow will undoubtedly emphasize the new biology that characterizes current research in malaria. Therefore, I thought it appropriate at the outset to refresh our memory of some features of malarial infection in the human host—features against which the new information must contend or which it should clarify.
Let us recall that infection with all species of human malaria is initiated under natural conditions by sporozoites from an infected mosquito. In each instance pre-erythrocytic development first takes place in parenchymal cells of the liver, releasing merozoites to initiate the asexual cycle in circulating red blood cells some 6 to 30 days later in most instances, depending upon the species of parasite and other factors.