AIDS vaccine investigators would have taken just about any positive indication in a major human trial as a hopeful sign. And today many were clearly impressed to see that a huge study of a combo HIV vaccine reduced the risk of being infected with HIV by 31 percent--the first tangible clinical proof in a quarter century that researchers appear to be on the right trail.
Mitchell Warren, executive director of the AIDS Vaccine Advocacy Coalition, called the trial data an "historic milestone," while NIAID Director Anthony Fauci told the AP he was surprised and pleased. Fauci added that investigators were not at the end of the road, but the trial had proved that "this is something that we can do."
The clinical trial in Thailand recruited 16,000 people to test a combination jab based on vaccines developed by Sanofi-Aventis and VaxGen. One involves a disabled virus used to insert gene fragments into the host to spur the work of killer T cells. The second involves an HIV protein intended to spur antibodies that attack HIV. The combo approach has now been tested in 16,000 volunteers.
Developing an effective HIV vaccine has proven to be an incredibly difficult task, eluding scientists for 25 years. Two years ago the entire research field was virtually derailed by the announcement that Merck's experimental vaccine had actually increased volunteers' risk of being infected by the stubborn virus. Now it appears to be back on track.