In combination with other promising clinical trials, the results have galvanized efforts to end the world's AIDS epidemic in a way that would been inconceivable even a year ago.
CHAPEL HILL, N.C. — An HIV discovery from researchers led by a University of North Carolina-Chapel Hill scientist is the biggest scientific breakthrough of 2011, according to the prestigious journal Science.
The study found that early treatment with anti-retroviral drugs sharply cut the risk that infected patients will transmit HIV, which is the virus that causes AIDS. That finding could help slow the spread of the disease, perhaps dramatically.
The journal announced picks for the year's top breakthroughs in its latest edition, which was published online Thursday afternoon. In addition to the HIV study, there were nine runners-up.
"In combination with other promising clinical trials, the results have galvanized efforts to end the world's AIDS epidemic in a way that would been inconceivable even a year ago," said an editorial appearing in the journal, which went on to cite a statement by U.S. Secretary of State Hillary Rodham Clinton last month that the goal of an AIDS-free generation is ambitious, but now possible.
"This is not to say that we can abandon the search for an AIDS vaccine," the editorial said, "or will profound change come overnight from the promise of using treatment as prevention. But for its role in making success conceivable, we have chosen the results of this trial as our Breakthrough of the Year."
Dr. Myron S. Cohen _ a professor of medicine, microbiology and immunology, and public health at UNC and the director of the UNC Institute for Global Health and Infectious Diseases _ is the principal investigator of the study, which he designed and organized.
The study found that people infected with the virus are 96 percent less likely to spread it to a partner if they begin a regimen of drugs sooner than normal.
It would be difficult to overstate the importance of that finding. The disease is estimated by the U.S. Agency for International Development to have killed more than 25 million people since first reported in 1981. It also costs billions of dollars worldwide each year in treatment and prevention efforts and lost productivity.
The nine-nation, $73 million study was funded by the National Institutes of Health. It began in 2005 and had been expected to last until 2015. But the results were so important that an independent monitoring board recommended last spring that researchers release their findings early and tell the study participants.
Since then, key international players in public health _ such as the World Health Organization, the President's Emergency Plan for AIDS Relief and the Joint United Nations Programme on HIV/AIDS _ have incorporated or are expected to incorporate the concept of treatment into their policy guidelines for battling AIDS.
Cohen said Thursday that he is elated about the honor from the journal not just for himself but for the research team and the university.
"This is big," he said. "I'm not going to have this happen again."
Cohen's expertise with HIV/AIDS is in transmission and prevention, and he has spent more than two decades building a team at UNC-Chapel Hill to study those topics.
After the board's recommendations, the researchers traveled to the 13 study sites spreading the word. They not only talked with study subjects but also explained the findings to ministers of health in all nine countries.
Antiviral drugs can be expensive and have side effects, so doctors often wait until a patient's immune system weakens to a certain level before recommending them.
The study was designed partly to determine whether early use of the drugs could reduce transmission and partly to look at the effects of the earlier treatment on those already infected.
It enrolled 1,763 couples at sites in Botswana, Brazil, India, Kenya, Malawi, South Africa, Thailand, the United States and Zimbabwe. Each couple included one partner who had HIV but still had a relatively healthy immune system, and one partner who was not infected.
These couples were randomly assigned to one of two groups. In one group, partners found to have HIV were immediately put on the drug regimen. In the other, the drugs were withheld unless the immune systems weakened to a certain point, though that point was still above the range recommended by the World Health Organization for beginning the use of the drugs.
When the board recommended ending the study, data indicated that among all couples enrolled, only 28 people contracted new infections of HIV that were linked via genetic testing to the infected partner in the study. Only one of those new infections occurred among couples in the immediate treatment group.
Heterosexual couples made up 97 percent of those in the study. The study results can't be used to draw conclusions about homosexual couples because so few were enrolled.
All the study subjects got health care, HIV testing and counseling on safe sex and condoms. It's not clear to what degree the subjects used the condoms, though they self-reported high rates of use. After the board recommended halting the study, patients with HIV in the deferred treatment group were offered the drugs. It's likely that both groups benefited from the study's focus on safe sex, Cohen said in an earlier interview.