New analysis throws doubt on HIV vaccine

LOS ANGELES–U.S. Army and Thai researchers announced to great fanfare last month that a combination vaccine had produced a statistically significant 31 per cent reduction in new HIV infections in a trial of more than 18,000 people in Thailand – a modest rate, but the first vaccine results that suggested it eventually might be possible to produce a vaccine against the deadly infection that has killed more than 25 million people.

In an unusual approach, the researchers decided to make the results public at a news conference rather than wait for formal publication of their findings. The complete results have yet to be made public.

Now, a secondary analysis of the results has suggested the vaccine was not quite as good as believed, reducing infections by only 24 per cent, according to researchers who spoke with Science magazine. The first analysis included all 16,000 people in the trial, The secondary excluded patients who did not follow the experimental regimen.

When that was done, the results were less convincing, according to experts who have seen the data.

Full details are to be made public Oct. 20.