PROTECTION AGAINST MALARIA BY IMMUNIZATION WITH A PLASMODIUM-YOELII CIRCUMSPOROZOITE PROTEIN NUCLEIC-ACID VACCINE

Nucleic acid vaccines provide an exciting new alternative approach to developing the multiantigen vaccines designed to induce protective ant ibody and T-cell responses against Plasmodium proteins that many exper ts believe will be required for effective protection against malaria. As a first step in this process, we produced a plasmid DNA vaccine tha r includes the gene encoding the P. yoelii circumsporozoite protein (P yCSP). This vaccine induced higher levels of antibodies and cytotoxic T lymphocytes against PyCSP than immunization with irradiated sporozoi tes, and protected 9 of the first 16 mice immunized. work is now in pr ogress to optimize immunization regimens, establish the mechanisms of protective immunity induced by the vaccine, and to determine whether p rotective immunity can be increased by vaccinating with multiple nucle ic acid vaccines designed to produce immune responses against multiple targets.