What is a four-gene DNA vaccine, and what are the four genes?
We have a large effort in our mouse malarias, and we’re focused in on a handful of genes in mouse malaria. Those antigens are the circumsporozoite protein. It’s a protein expressed by the sporozoite form of the parasite. We’re working on an antigen called SSP2, which is the sporozoite surface protein #2. We’re working on a protein called “HEP17,” which again is a mouse malaria antigen. We’re looking at an antigen called “AMA-1,” an apical membrane antigen. There’s one called “MSP-1,” which is a merozoite surface protein, as well as a few others in mice. We’ve had quite a lot of experience in the mouse model, and over the past 18 months or so we’ve developed now a new model in rhesus monkeys. So we can take malaria infected mosquitoes-and these are Plasmodium knowlesi, which is a monkey malaria-we can take these mosquitoes, we can take them the sporozoites from them or allow the mosquitoes themselves to feed on monkeys, and we can challenge those monkeys to see if our vaccines protect a
