Bill Gates: HIV vaccine is more than a decade away

Microsoft founder Bill Gates, who spends hundreds of millions on HIV vaccine research and other health care projects through his Bill and Melinda Gates Foundation, says an HIV vaccine is at least a decade away, The Wall Street Journal reports. Speaking in the United Kingdom, where he received an honorary knighthood for his philanthropic work, Gates said, "I'll eat my hat" if an effective vaccine were developed within the next decade, according to the Journal. Gates says funding the development of an HIV vaccine is the primary goal of his foundation, which last month pledged $360 million over five years toward HIV vaccine research and is a major supporter of international vaccine research organizations. But developing an effective HIV vaccine has proven particularly difficult because of the nature of the virus to mutate defenses against drugs and vaccines aimed to control it and due to the numerous genetically unique HIV strains. There are currently about 30 experimental HIV vaccines being tested in humans, but none is expected to be able to completely prevent HIV infection, according to officials at the National Institutes of Health.