Jef Akst | Jul 19, 2009 | 3 min read
New findings have disproved a leading explanation for why an experimental HIV vaccine made subjects more susceptible to the virus, reopening the door for further HIV vaccine efforts based on similar principles. Human Immunodeficiency VirusImage: NIAIDThe Merck-funded STEP study, which used an adenoviral vector to deliver an HIV vaccine candidate, was halted in 2007 after the data suggested the vaccine increased the risk of HIV infection. Researchers thought the effect might be due to an immune