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 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 cited a statement by U.S. Secretary of State Hillary 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, STLtoday reported.