AIDS researchers are discussing where to go next, after a potential vaccine failed in two human trials several months ago. As VOA's Kent Klein reports, numerous approaches were considered at the Summit on HIV Vaccine Research and Development.

Several hundred HIV/AIDS scientists and advocates discussed and debated how to move forward with AIDS research. The main question was whether to continue with clinical trials of experimental vaccines on humans, and if so, how much to rely on those trials.

Dr. Anthony Fauci is a leading voice for AIDS research, and the Director of the U.S. National Institutes of Health's Allergy and Infectious Diseases area, which sponsored the meeting on Tuesday. He said that despite recent disappointments in efforts to develop a vaccine, research toward that end will continue.

"So the idea about stepping back and pausing and seeing if you have the right balance between fundamental answering of questions that are critical versus moving ahead with trying to develop a countermeasure, be that a drug or a vaccine or a diagnostic, is a natural evolution of the path towards a vaccine," he said.

Two human trials of an experimental AIDS vaccine were stopped late last year, when it appeared that the drug not only failed to protect against the disease, but in some cases put people at higher risk of getting it. Since then, support for clinical studies of existing experimental AIDS vaccines has diminished.

While many of the experts at the summit agreed that clinical studies should continue, many researchers urged reducing the dependence on human trials. Dr. Anthony Fauci and others recommend supplementing human trials with increased drug trials on animals, specifically lower primates.

"There is good discovery research that you can get out of an animal model, just as there's good discovery research that you can get out of clinical research," he said.

Dr. Mark Conners is a senior clinical investigator at the National Institutes of Health. While he concurs that the recent failures in clinical trials set the cause of finding a vaccine back considerably, he believes there are other avenues to be pursued.

"I'm not necessarily optimistic about some of the products we currently have, but I am, longer-term, optimistic that with the proper immune correlates, or, even, ultimately, if that fails, without them, that the immune response can control HIV. We have several natural examples of that," he said.

Still, the scientists seemed to agree that an AIDS vaccine is not likely soon and that it's important to train future researchers to carry on their work.