科学：2011年的突破

The journal Science has named an AIDS study as its 2011 Breakthrough of the Year. The clinical trial found that antiretroviral drugs can be used to dramatically lower the risk of transmitting HIV.

The clinical trial is known as HPTN 052. It proved that giving the drugs to HIV infected people sooner made them 96 percent less likely to transmit the virus to their uninfected partners.

The research team was led by Dr. Myron Cohen. He said while the results were announced in May, preliminary work actually began 20 years ago.

“We had a strong suspicion based on all the biological studies we had done that when we treat people and lower the concentration of HIV in the blood and secretions, we were rendering them less contagious. But we didn’t understand the magnitude of the benefit,” he said.

Cohen is director of the Institute for Global Health and Infectious Diseases at the University of North Carolina at Chapel Hill.

“Suppose we had found that as we treat people they’re rendered 50 percent contagious. That’s a lot different than saying we’ve rendered people completely non-contagious. And so, the result, while it takes a long time, has attracted so much attention because it inspires the aspiration to aggressively prevent transmission. It blows a gigantic wind behind the idea that treatment will serve as prevention,” he said.

Follow through

Data from the study has already been put to use on many levels.

“This particular 052 study in the last six months has generated policy changes at the level of the United States and the World Health Organization and UNAIDS. And it’s inspired new community-based clinical trials that are just about to be launched that apply the scientific discovery. So when you do a single study and it receives so much recognition and then seems to inform policy in a dramatic way you think, ok, this was 20 years well spent,” said Cohen.

Those policy changes include treating HIV-infected people when their immune systems are still relatively healthy. The study also encouraged President Obama and Secretary of State Hillary Clinton to say an end to HIV/AIDS is possible.

Seize the day

However, Cohen said the study results will be wasted unless they are linked to other aspects of HIV treatment and prevention.

“So the 052 study kind of lends itself to understanding that if we don’t know who’s positive and negative there’s no benefit. If people aren’t linked to care, there’s no benefit. If they aren’t provided drugs, there’s no benefit. If they receive the drugs but don’t take the pills, there’s no benefit. So this cascade is now the focus of our attention,” he said.

Cohen is well aware the study results were announced amid a global recession when many donors were reducing spending. Nevertheless, he said he remains optimistic about the future.

“So, as the world recession goes forward, it would seem insensible to ignore this disease, just as it would be insensible to ignore tuberculosis. You either pay now or pay later,” he said.

Praise for HPTN 052

Among those who celebrated the study results was Mitchell Warren, head of the AIDS advocacy group AVAC.

“Treatment is prevention. And that becomes a fundamentally different conversation because for many years debates have waged whether we should do treatment or prevention. And the results of the HPTN 052 study actually affirm once and for all that treatment is prevention,” he said.

He said the last 12 to 18 months brought other encouraging news as well. This includes successful microbicide studies, proof that antiretroviral drugs can prevent initial HIV infection and advances in vaccine research. Warren agrees the end of the HIV/AIDS epidemic is within reach.

“We know it’s possible, now we just need to do it,” he said.

The HPTN 052 study was sponsored by the National Institute of Allergy and Infectious Diseases. Director Dr. Anthony Fauci says the recognition by the journal Science is a credit to researchers and the more than 3,000 study participants.