Two new studies in this week’s issue of the journal Science demonstrate that the scaling up of HIV antiretroviral treatments in the rural province of KwaZulu-Natal, South Africa has been worth the hefty price tag.

Despite a continuing stigma about AIDS in Iran, the nation’s health authorities are winning praise globally for their response to the disease and have been more open about the number of cases and the routes of transmission, an Iranian-born American scientist said at AAAS recently.

Navid Madani, a research scientist at the Dana-Farber Cancer Institute in Boston, helped organize an international AIDS meeting in Tehran 22-25 October. Close to 300 people attended, including seven invited speakers from the United States, and there was some unexpectedly frank talk about the disease.

Treatment is part of a total effort to contain the spread of most infectious diseases, from gonorrhea to tuberculosis. Most experts assumed that would apply to HIV as well—that treating people with antiretroviral therapy and lowering their HIV viral load would reduce the risk of transmission to others—but definitive evidence has been lacking.

Last year, a landmark National Institutes of Health clinical trial finally provided spectacular proof—a 96% reduction in new infections—of the preventive potential of treatment.

The journal Science has lauded an eye-opening HIV study, known as HPTN 052, as the most important scientific breakthrough of 2011. This clinical trial demonstrated that people infected with HIV are 96% less likely to transmit the virus to their partners if they take antiretroviral drugs (ARVs).