Experimental AIDS Vaccine May Increase HIV Risk
Hundreds of trial volunteers being notified in South Africa
By Sam Gale Rosen,  Newser Staff
Posted Oct 25, 2007 6:38 PM CDT
An employee walks past a stained-glass window, bearing Merck & Co.'s name, as he walks to the elevator at the company's headquarters in a Whitehouse Station, N.J. file photo from Sept. 30, 2004. (AP...   (Associated Press)
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(Newser) – A once-promising AIDS vaccine being developed by Merck may actually increase the risk of contracting HIV, the Washington Post reports. In South Africa, 19 people who received the vaccine in a trial contracted the virus, as opposed to 11 who received a placebo. South  African researchers have begun warning hundreds of participants of the findings.

The vaccine trials began in 2004, not only in South Africa but in several other countries, including the US. Researchers are trying to determine if the South African numbers are a fluke or if all participants need to be informed. They will meet next month to go over the data. The failure of the vaccine would be a devastating blow to the entire field, the Post says.