Early treatment of HIV-infected people with ARVs dramatically protects partners from infection

Men and women infected with HIV reduced the risk of transmitting the virus to their sexual partners significantly 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 USA’s National Institutes of Health.

The clinical trial, known as HPTN 052, was slated to end in 2015 but 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.

In its review, the DSMB found a total of 39 cases of HIV infection among the previously uninfected partners. Of those, 28 were linked through genetic analysis to the HIV-infected partner as the source of infection. Seven infections were not linked to the HIV-infected partner, and four infections are still undergoing analysis. Of the 28 linked infections, 27 infections occurred among the 877 couples in which the HIV-infected partner did not begin antiretroviral therapy immediately. Only one case of HIV infection occurred among those couples where the HIV-infected partner began immediate antiretroviral therapy.