Experimental AIDS vaccine shows unexpected efficacy in trial.

Experimental AIDS vaccine shows unexpected efficacy in trial.

The Washington Post (9/24, Brown) reports, "An experiment in Thailand involving 16,000 men and women has demonstrated for the first time a small but measurable protective effect of an AIDS vaccine." The Post calls the results "barely significant on statistical grounds, perplexing for scientific reasons and unanticipated by most researchers. Nevertheless, the first positive results for an AIDS vaccine after two decades of experimentation was being called a milestone."

"I don't want to use a word like 'breakthrough,' but I don't think there's any doubt that this is a very important result," Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Diseases (NIAID), told the New York Times (9/24, McNeil). The vaccine, known as RV 144, "protected too few people to be declared an unqualified success. And the researchers do not know why it worked."

The AP (9/24, Marchione, Casey) reports, that "the vaccine cut the risk of becoming infected with HIV by more than 31 percent." It is a combination of Sanofi Pasteur's ALVAC "and AIDSVAX, originally developed by VaxGen Inc." The vaccine was tested "in a 'prime-boost' approach, where the first one primes the immune system to attack HIV and the second one strengthens the response."

The US Army funded the study along with the NIAID and the NIH, Bloomberg News (9/24, Bennett) adds. For the study, "researchers enrolled volunteers in Thailand's Chon Buri and Rayong provinces, which have the nation's highest rates of HIV." Volunteers "were given four doses of the ALVAC vaccine and two of the AIDSVAX shot over six months, then monitored for three years. They were also given advice on safe sex."

Researcher Dr. Jerome Kim, a US Army colonel at the Walter Reed Army Institute of Research, said, "We had 74 infections in the placebo group and 51 in the vaccine group," Reuters (9/24, Fox) reports. Dr. Fauci admitted that he "did not think there was a very high chance that this would give any degree of efficacy." Dr. Fauci added that "nonetheless, we went ahead with the trial and it was controversial to go ahead with it."