Bill Gates says a malaria vaccine could be as little as three years away, with a prototype entering final trials.
"A partially effective vaccine could even be available within three years, but a fully effective vaccine will take five to 10 years," he told the BBC.
Human trials of the vaccine started last summer.
Known as RTS,S, it is based on a weakened strain of the entire Plasmodium parasite. Other researchers are working to combine it with other potential vaccines to improve its effectiveness further.
Malaria is one of the world's biggest killers. It affects as many as 500 million people per year and kills 2,000 children a day in Africa.
The Bill & Melinda Gates Foundation has poured billions of dollars into the eradication of the disease. As well as working towards an effective vaccine, the Foundation has invested in new malaria drugs and mosquito control techniques such as improved insecticides and the provision of bed nets.
But in an open letter yesterday, Gates warned that budget deficits and efforts to cut global warming could impact on third world aid. "I am concerned that some of this money will come from reducing other categories of foreign aid, especially health," he wrote.