The U.S. government began a major overhaul of its effort to produce an AIDS vaccine on Tuesday, stressing basic scientific research after the failure of a key clinical trial last year.
Government officials at a summit with AIDS scientists pledged to prioritize spending on lab work and animal tests rather than expensive, and thus far disappointing, clinical vaccine trials on humans.
"We need to turn the nob in the direction of discovery. That is unambiguous," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, who convened the meeting outside of Washington.
"We really do need new and novel ideas."
The vaccine summit follows the failure last year of an experimental HIV vaccine developed by Merck & Co which had been widely touted as one of the best hopes in the field.
Clinical trials, however, indicated that the vaccine candidate did not protect against infection with the AIDS virus and might even have made recipients more susceptible, although how is not exactly clear.
Scientists said the surprising outcome of the Merck trials demonstrated how little HIV is understood after more than two decades of intensive research.
"Despite hundreds and hundreds of millions of dollars, the reality is that in 2008 an effective HIV/AIDS vaccine is beyond our grasp," said Warner Greene, a co-chair of the summit and professor of medicine at the University of California-San Francisco.
"There is no question in my mind that the HIV vaccine effort is in need of a major mid-course correction."
Fauci suggested that the overall AIDS research budget at his institute, now at about $1.5 billion, could tilt more in favor of basic laboratory work rather than vaccine development, which currently accounts for about one-third of spending.
"We really need to seriously look at torquing that balance more to answering some of the fundamental questions that we don't have answers to," he said.
Nearly 30 potential AIDS vaccines are being tested on people around the world, and advocates argue that ultimately an effective vaccine would be the best way to stop a virus that still infects some 12,000 people every day. Globally, AIDS has killed about 25 million people.
Some AIDS advocacy groups have criticized U.S. spending on the vaccine effort. The AIDS Healthcare Foundation this week said suspending U.S. funding for a vaccine and investing in strategies that save lives and stop new infections would be the wisest and most effective use of limited public resources.
Many scientists at Tuesday's meeting called for more research on animals, saying that nonhuman primates such as rhesus and macaque monkeys could serve as valuable stand-ins for human subjects.
"It's a great model. I'm not sure we've used it to best advantage," said Louis Picker, associate director of the Vaccine and Gene Therapy Institute at Oregon Health and Sciences University.
But other participants cautioned against moving too far away from clinical research.
"We have to keep humans in the picture. What we really need is better communication on the science," said Dr. Peter Anton of the UCLA AIDS Institute.