| As the number of drug-resistant malaria parasites continues to grow, pressure is increasing to find an effective, cross-protective, multi-valent malaria vaccine (32). Expression library immunisation is an un-biased screening technique that leads to the identification of novel, protective antigens that can be administered as components of a multivalent DNA vaccine (9, 50, 75, 86, 92). Here, a P. c. adami DS expression library has been evaluated as a malaria vaccine in mice, and several subpools of cross-protective plasmids have been identified. Upon vaccination with these plasmid subpools, mice demonstrate significantly lower mean cumulative parasitemia values than control vaccinated mice, when challenged with avirulent heterologous P. c. adami DK parasites. These cross-protective responses correlate with the induction of opsonizing antibodies against infected red blood cells and the production of IFN-gamma by T-cells. The determination of P. c. adami antigens capable of inducing strain-transcending immunity implies the identification of orthologues in the P. falciparum genome that may be applied as components of a human malaria vaccine. |
