A study by a unit of the National Institutes of Health found that men and woman with HIV reduced the risk of transmitting the virus to sexual partners if they were taking antiretroviral drugs and had a healthy immune system.
The large clinical study, sponsored by the NIH's National Institute of Allergy and Infectious Diseases (NIAID), marks a prevention breakthrough. The clinical trial was going to end in 2015, but the findings were released early for a data review.
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 Fauci said:
"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."
The study started in April 2005 and enrolled 1,763 couples at 13 sites around the world. The NIH noted the data set was small in the U.S. due to difficulty enrolling companies. As a result, the data set is largely from areas such as Botswana, Brazil, India, Kenya, Malawi, South Africa, Thailand and Zimbabwe.
According to the NIH, the HIV drugs from a bevy of pharmaceutical companies were used. The research group is now looking into the best timing to take antiretroviral drugs.