Experimental HIV vaccine shows promise

Sep 25 2009

An experimental HIV vaccine raises hope of reducing the risk of infection.

Wall Street Journal/Associated Press reports: "For the first time, an experimental vaccine has prevented infection with the AIDS virus, a watershed event in the deadly epidemic and a surprising result. Recent failures led many scientists to think such a vaccine might never be possible."

"The vaccine cut the risk of becoming infected with HIV by more than 31% in the world's largest AIDS vaccine trial of more than 16,000 volunteers in Thailand, researchers announced Thursday in Bangkok. ... Even a marginally helpful vaccine could have a big impact. Every day, 7,500 people world-wide are newly infected with HIV and two million died of AIDS in 2007, the U.N. agency UNAIDS estimates. ... The Thailand Ministry of Public Health conducted the study, which used strains of HIV common in Thailand. Whether such a vaccine would work against other strains in the U.S., Africa or elsewhere in the world is unknown, scientists stressed. The study actually tested a two-vaccine combo in a "prime-boost" approach, where the first one primes the immune system to attack HIV and the second one strengthens the response" (9/24).

CNN reports that Col. Jerome Kim, who is the HIV vaccines product manager for the U.S. Army, "emphasized that the level of efficacy was modest, but given the failures of previous HIV vaccine trials, 'yesterday we would have thought an HIV vaccine wasn't possible.' He called the results from the trial an important first step that will help researchers work toward a more effective vaccine. Researchers have tried to prevent the spread of HIV since they discovered its cause in 1986. Previous vaccine trials failed to prevent infection. And during one trial, the vaccine seemed to boost the chance of being infected, which ended testing early. ...

"The new study was conducted in Thailand, with more than 16,000 people between ages 18 and 30 participating. They were all HIV negative at the beginning of the trial. Nearly 8,200 received a placebo and a similar number received a combination of six vaccines over six months. All were followed for three years. ... The study was funded by the National Institutes of Allergy and Infectious Diseases and the U.S. Army Medical Research and Materiel Command. According to Kim, the U.S. military was involved in the study because U.S. service members are at risk and 'there's a national security threat from HIV'" (Falco, 9/24).

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