“Men and women infected with HIV reduced the risk of transmitting the virus to their sexual partners by taking oral antiretroviral medicines when their immune systems were relatively healthy,” according to findings from a large-scale clinical study sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. The clinical trial, known as HPTN 052, was slated to end in 2015 but NIH said the findings are being released early as the result of a scheduled interim review of the study data by an independent data and safety monitoring board (DSMB). The DSMB “concluded that it was clear that use of antiretrovirals by HIV-infected individuals with relatively healthier immune systems substantially reduced transmission to their partners. The results are the first from a major randomized clinical trial to indicate that treating an HIV-infected individual can reduce the risk of sexual transmission of HIV to an uninfected partner.” NIAID Director Anthony S. Fauci, M.D commented, “Previous data about the potential value of antiretrovirals in making HIV-infected individuals less infectious to their sexual partners came largely from observational and epidemiological studies. This new finding convincingly demonstrates that treating the infected individual—and doing so sooner rather than later—can have a major impact on reducing HIV transmission.”

http://www.nih.gov/news/health/may2011/niaid-12.htm