October 20, 2008
Researchers at the AIDS Vaccine 2008 conference in Cape Town, South Africa, last week examined how setbacks in developing a vaccine have "forced them to look for entirely new ways of creating a defense against the disease," AFP/Google.com reports. "We are in the middle of quite a profound shift of mindset in the research community," Alan Bernstein, director of the Global HIV Vaccine Enterprise, said at the conference, which ended on Friday. He added that setbacks have made researchers examine new research methods in the effort to develop an HIV/AIDS vaccine (Blandy, AFP/Google.com, 10/18).
Merck in September 2007 announced it had halted a large-scale clinical trial of its experimental HIV vaccine after the drug failed to prevent HIV infection in participants or prove effective in delaying the virus' progression to AIDS. The vaccine candidate also might have put some trial participants at an increased risk of HIV. Following news of the Merck vaccine, trials of NIH's Vaccine Research Center's HIV vaccine candidate were scaled back (Kaiser Daily HIV/AIDS Report, 10/16).
"The Merck result was such a surprise, and everyone was kind of shocked off their horses," Mitchell Warren of the AIDS Vaccine Advocacy Coalition said, adding, "What happened, no one could have predicted. They still don't understand exactly what happened. That finding forces people to realign and look at new ways and new approaches to how we are going to find an AIDS vaccine because it was so surprising." According to Warren, the results of the Merck trial have made researchers rethink assumptions about how vaccines work. "People are really grappling with new ways of doing things," he said.
About 30 clinical trials for vaccine candidates are under way worldwide, and the "most watched" is a study in Thailand that began in 2003, according to AFP/Google.com. Results from the trial are expected next year, and about 16,000 people are participating. According to some researchers, the trial will provide important information about HIV/AIDS whatever its outcome.
According to Bernstein, the most interesting new research into HIV/AIDS vaccines involves defenses in the body called the innate immune system. The innate immune system serves as an "early warning system for invading diseases," AFP/Google.com reports, and Bernstein said that the system could stop HIV if researchers determine a method of triggering it early. "We now know we may have only hours, at most days, before we have a window of opportunity to stop HIV," he said, adding, "So that's reason to think this early warning system might be critical to activate if we are going to design a vaccine" (AFP/Google.com, 10/18).
Reprinted with permission from kaisernetwork.org. You can view the entire Kaiser Daily HIV/AIDS Report, search the archives, or sign up for email delivery at www.kaisernetwork.org/dailyreports/hiv. The Kaiser Daily HIV/AIDS Report is published for kaisernetwork.org, a free service of the Kaiser Family Foundation, by The Advisory Board Company. © 2008 by The Advisory Board Company and Kaiser Family Foundation. All rights reserved.