'Great moment' in war on AIDS

A late-stage trial combining two HIV vaccines was shown to reduce the chance of infection by a third, raising the prospects that in time AIDS can go the way of polio as an eradicated disease.

The study, conducted by the U.S. Army's surgeon general, nonetheless showed that there's a long way to go—infection rates were cut only by roughly a third in a large study in Thailand.

That's not good enough for immediate use, researchers say. Yet it is a watershed event in the 26 years since the AIDS virus was discovered. Recent setbacks led many scientists to think a successful vaccine would never be possible.

The World Health Organization and the U.N. agency UNAIDS said the results "instilled new hope" in the field, even though it likely will be years before a vaccine might be widely available.

"This is truly a great moment for world medicine," said Lt. Gen. Eric Schoomaker, the U.S. Army Surgeon General. The Army helped sponsor the study, the world's largest of an AIDS vaccine.

It was the first time scientists tried preventing HIV the same way they treat it — with a combination approach. The study used two vaccines that work in different ways, and that may be one reason the strategy worked, even though neither vaccine did when tested individually in earlier trials, scientists say.

The combo cut the risk of becoming infected with HIV by more than 31 percent in the study of more than 16,000 volunteers in Thailand, researchers announced Thursday in Bangkok.

That benefit is modest, yet "it's the first evidence that we could have a safe and effective preventive vaccine," said Col. Jerome Kim, an Army doctor who helped lead the study.

The outcome "gives me cautious optimism about the possibility of improving this result" and developing a more effective AIDS vaccine, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, which co-sponsored the study.

"It's an opening of a new gateway to a road that has brighter lights in it now and maybe some directions," he said. "We need to bring the best minds together and map the way forward."