Antimalarial transmission-blocking vaccines

In the continuing efforts to develop strategies to limit the impact of malaria, scientists are constantly modifying established methods of vector control and antiparasite chemotherapy. Despite their best efforts malaria remains a major lethal and debilitating disease in the tropics annually killing 2 million children in Africa. New technologies have prompted the evaluation of vaccines as potentially powerful tools to ameliorate the impact of the parasite upon the infected human host, and more recently to block the transmission of the parasite from man to the mosquito vector. Laboratory studies suggest these transmission-blocking vaccines may reduce transmission significantly and one candidate antigen is now being prepared for human trials. This article reviews the properties and merits of transmission-blocking vaccines; describes the various candidate antigens under development; raises questions that still need to be answered; and indicates some of the unexpected approaches that are now being considered in our attempts to control this important pathogen.