A vaccine against malaria could be on the market by 2010. In a drug trials among 2,022 children in Mozambique, the risk of a single episode of malaria was reduced by 30% and risk of serious infection by 58%. While researchers caution that it's no magic bullet--"Just like any other malaria control tool that we have, like insecticide treated nets... none of them is 100% effective...Control will rely on using a combination of malaria control tools together"--an effective vaccine could encourage continued reductions in the use of DDT to kill mosquitos, which spread the disease. There are about 300 million severe cases of malaria a year, and at least 1 million deaths.