Washington: A study suggesting that HIV transmission can largely be prevented with antiretroviral drugs has been named the most important breakthrough of the year by one of the world's leading scientific journals.
   
The journal Science has announced that the results of the "HPTN 052" trial, which were published in May, were the most important findings of 2011.
   
The HPTN 052 trial was a study of 1,763 couples, where one partner was HIV-positive and the other was not. Half the infected people received antiretrovirals, and the researchers found a 96 percent reduction in transfer of the virus.
   
These results were discovered as the researchers prepared for a data and safety monitoring board meeting in the midst of the study, and as a result, the trial was ended four years early and all participants were offered antiretroviral treatment.
   
"HIV prevention has had very few successes," said Jon Cohen, a correspondent for the journal who nominated the trial to the committee deciding the award.
   
"The biomedical success story was limited for many years to prevention of mother to child transmission," said Cohen.
   
While condom use, behaviour change and circumcision have been shown to prevent HIV, "the list of failures that have happened in prevention is incredibly long," Cohen said.
   
Calling HPTN 052 the cornerstone, Cohen said, "It's not, in and of itself, going to solve the problem, it's not going to end the epidemic."
   
"It's not a vaccine,” Cohen said, "but it's the next best thing, and it's available today."
   
Now, the question is would the drugs work for everyone?
   
Because the study was conducted in heterosexual couples, it's unclear whether the same benefit would extend to men who have sex with men, the researchers said.
   
Some ongoing studies are attempting to answer that question, and while the mechanisms behind transmission differ slightly, it seems all uninfected partners would benefit from antiretroviral drugs, they said.
   
In fact, it may be unethical to run a similar trial in homosexual men at this point, given the strong evidence that the drugs work, because such a trial could be seen as withholding effective treatment from the people in the control group, said Carl Dieffenbach, of the National Institute of Allergy and Infectious Disease which sponsored HPTN 052 trial.
   
"I certainly think it's an important study," said Kevin Frost, Chief Executive of amFAR, the Foundation for AIDS Research. "It has begun to shape the conversation about the role of continuing to try and scale up treatment efforts worldwide, to get people onto treatment."
   
But, Frost said, he is skeptical about getting funding and support for such efforts.
   
An NIH-funded trial, called START, is under way to determine just how soon after infection antiretroviral therapy should be started.
Dieffenbach said he is concerned with getting people to start and adhere to antiretroviral therapies.
   
The problem, he said, is what is known as the "treatment cascade": For every 100 patients who are HIV-positive, 79 are aware of it, 47 of those are linked to care, and only 26 are
on treatment that is suppressing the virus in their blood.
   
"This is the fundamental challenge that we face now. We absolutely know that treatment matters," he said.

(Agencies)