Merck Halts AIDS Vaccine Tests

Posted on September 24, 2007

There was some very unfortunate news earlier this week when Merck reported that it was halting its AIDS vaccine test because tests showed the vaccine was not working - people were still getting infected with the HIV virus.

Merck & Co. said Friday that it is ending enrollment and vaccination of volunteers in the study, which was partly funded by the National Institutes of Health.

It was a high-profile failure in the daunting quest to develop a vaccine to prevent AIDS. Merck's vaccine was the farthest along, considered the most promising and was closely watched by experts in the field.

The test was an obvious failure because more people who received the vaccine later became HIV positive than those who received dummy shots.
Officials at the company, based in Whitehouse Station, N.J., said 24 of 741 volunteers who got the vaccine in one segment of the experiment later became infected with HIV, the virus that causes AIDS. In a comparison group of volunteers who got dummy shots, 21 of 762 participants also became infected.

"It's very disappointing news," said Keith Gottesdiener, head of Merck's clinical infectious disease and vaccine research group. "A major effort to develop a vaccine for HIV really did not deliver on the promise."

It is a big failure but it isn't the end of the quest for an AIDS vaccine. A New York Times article cites Wayne C. Koff, a senior vice president of the International AIDS Vaccine Initiative in New York. Koff told the Times that there are about thirty other H.I.V. vaccines are being tested in people.

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