Anti-HIV medications provide durable protection against heterosexual transmission, study finds

University of North Carolina Health Care SystemJul 19 2016

Anti-HIV medications suppress the viral load of people living with HIV and provide durable protection against heterosexual transmission a study led by the University of North Carolina at Chapel Hill found. Researchers found a 93 percent reduction of HIV transmission when the HIV-infected person started antiretroviral therapy or ART at a higher CD4 cell count. The groundbreaking final results of the HIV Prevention Trials Network (HPTN) 052 study were published in the New England Journal of Medicine.

"The HPTN 052 study confirms the urgent need to treat people with HIV infection as soon as infection is diagnosed to protect their health and for public health," said Myron S. Cohen, M.D., Director of the UNC Institute for Global Health and Infectious Diseases and Principal Investigator of HPTN 052. "This study represents more than a decade of effort by a worldwide team of investigators, and the tremendous courage and generosity of more than 3,500 clinical trial participants."

Worldwide, 37 million people are living with HIV. HPTN 052 began in 2005 and enrolled 1,763 HIV-serodiscordant couples - where one person was living with HIV and the other was not - at 13 sites in nine countries (Botswana, Brazil, India, Kenya, Malawi, South Africa, Thailand, the United States and Zimbabwe). Ninety-seven percent of the couples were heterosexual. HIV-infected participants were assigned at random to start ART at the beginning of the study when their immune system was relatively healthy (called the "early" arm), or later in the study when they had immune system decline (called the "delayed" arm).

In 2011, interim study results demonstrated significant benefit of early ART, with a 96 percent reduction in HIV transmission from early ART compared to delayed ART. This finding was reported based on the recommendation of the study's data safety and monitoring board; presented at the 6th International AIDS Society (IAS) Conference on HIV Pathogenesis, Treatment and Prevention in Rome, Italy; and published in NEJM.

All HIV-infected participants in the study were then offered ART and the study was continued until May 2015 to understand the magnitude and durability of "treatment as prevention"; 87 percent of the HIV-infected participants remained in the study for its 10-year duration.

The HPTN 052 results have helped to galvanize a worldwide commitment to a universal "treatment as prevention" strategy for combating the HIV/AIDS epidemic, with ART offered to all HIV-infected people, regardless of CD4 cell count.