A novel method for development of malaria vaccines using full-length cDNA libraries.

We describe a novel method to screen malaria DNA vaccine candidates using a full-length cDNA library and a murine malaria infection model. For the development of effective malaria vaccines, much effort has been made with meager success. The completion of genome sequencing of Plasmodium falciparum has provided invaluable information for achieving this goal. We have been studying full-length cDNA libraries of malaria parasites as a part of genome analysis. Mice vaccinated with a DNA vaccine consisting of 2000 pooled clones showed significantly prolonged survival after challenge infection. In addition, spleen cells of vaccinated mice produced augmented levels of IL-2 and IFN-gamma when incubated with the crude parasite antigens, indicating that cellular immunity plays an important role in the protection. This approach will not only form the basis for development of malaria vaccines but will also be applicable to other parasites and pathogenic microorganisms.