RV144, an experimental HIV vaccine at the center of the largest human AIDS trial to date, is the first to show a significant result in HIV prevention.

The study, a joint effort between vaccine patent-holders and U.S. and Thai governmental agencies, involved more than 16,000 Thai volunteers -- half who received six doses of the vaccine in 2006, half who received a placebo.

Though RV144 was shown to be only 31% effective against infection, the trial results left researchers stunned and renewed hope that a vaccine against the deadly disease is still possible.

In a brief interview, Advocate.com spoke about the findings with Mitchell Warren, executive director of AIDS Vaccine Advocacy Coalition.

Advocate.com: How does the RV144 study differ from past studies that showed no significant evidence of protection against HIV infection?

Mitchell Warren: Previous efficacy studies looked at either antibody response or a cellular [CD4- or CD8-cell] response. This trial was the first large-scale efficacy trial to try a prime-boost combination vaccine, one meant to stimulate both cellular and antibody responses.
 
What’s the bottom line of this study?

It’s the first time we’ve had any significant positive result for a vaccine. We’ve always fundamentally believed that a vaccine is possible, but the clues have always come from various animal studies, elite controllers [people who are infected with HIV but never develop symptoms of AIDS], and highly exposed uninfected individuals.