New Hope for HIV Vaccine
Increased Funding and Expanded Studies Fuel Efforts
Aug. 16, 2006 (Toronto) -- There is renewed hope for the development of an HIV vaccine, thanks to increased funding, a better understanding of how the virus wreaks havoc in the body, and scaled-up testing in developing nations, researchers say.
But a vaccine, widely considered to be the best way to control the epidemic, is probably still years away -- mainly because scientists haven't figured out how to prevent the rapidly mutating virus from evading the body's disease-fighting immune system.
"In the last two years, a series of new initiatives from the Gates Foundation, the National Institutes of Health, and others have driven the science," says Seth Berkley, MD, head of the International AIDS Vaccine Initiative. In the past month alone, vaccine research received a $287 million shot in the arm from the Bill and Melinda Gates Foundation.
"A few years ago, we had a couple of scientists tinkering in their lab and now we have collaborative worldwide efforts trying to solve the problem," he says.
That said, there are still miles to go, says Françoise Barré-Sinoussi, MD, of the Institut Pasteur in Paris. "Everyone is looking for a vaccine, but we don't even know if a vaccine is possible," she says. Berkley, Barré-Sinoussi, and others spoke with WebMD about the state of vaccine development at the XVI International AIDS Conference here.
More Than 30 Vaccines in Testing
More than 30 experimental vaccines are now in various stages of human testing in more than 24 countries, with Merck & Co.'s product furthest along, Berkley says.
But even the study of that vaccine isn't expected to produce results until 2008. And even if it does work, the vaccine will not protect against new infections, but rather prevent newly infected people from developing full-blown AIDS, he says.
That's because the vaccine doesn't rely on the typical approach of teaching the body to recognize the virus and create antibodies to neutralize it before it infects cells.
Instead, the vaccine is designed to boost the ability of killer T cells (immune cells) to seek and destroy cells already infected with HIV.
"By giving it before infection, before the immune system becomes destroyed by the virus, the hope is that if a person does become infected, the vaccine will keep the virus in check and prevent disease progression," Berkley says.
Whether it will work is still anyone's guess. If it doesn't, vaccine research will probably turn to the traditional approach of stimulating the production of antibodies to defuse the virus before it takes hold in the body, he says.
In fact, many researchers believe that an effective vaccine will need to boost both neutralizing antibody and killer T cell production, Barré-Sinoussi says.