Study Finds No Risk of HIV Transmission while on Antiretroviral Treatment

A new study published in The Lancet found zero risk of HIV transmission with a partner while on effective antiretroviral treatment (ART).

The study, called PARTNER2, looked at 972 gay male couples who were serodifferent – one parter was HIV positive, the other negative – over the course of eight years. Over a third of the HIV negative men reported having condomless sex with their partners.

On average, the HIV-positive partners were on ART for about four years. Most of them adhered to ART; only 5 percent reported missing ART for four or more consecutive days throughout the study.

Over the course of these eight years, only 15 of the HIV-negative men contracted the virus. However, researchers confirmed through genetic tests that none of their partners transmitted the virus; the contraction occurred outside of the couple.

“Our findings provide conclusive evidence for gay men that the risk of HIV transmission with suppressive ART is zero,” said Professor Alison Rodger, a co-leader of the research. “Our findings support the message of the international U=U campaign, that an undetectable viral load makes HIV untransmittable.”

The study was not without limitations – most of the participants were white and older, with an average age of 38. Most new HIV cases occur in gay or bisexual men under 25.

Regardless, Dr. Michael Brady, Medical Director at Terrence Higgins Trust and National NHS Advisor for LGBT Health, said it’s “impossible to overstate the importance of these findings,” according to PinkNews.

“The PARTNER study has given us the confidence to say, without a doubt, that people living with HIV who are on effective treatment cannot pass the virus on to their sexual partners,” Dr. Brady said. “This has incredible impact on the lives of people living with HIV and is a powerful message to address HIV-related stigma.”

Rodger added that the next step is spreading this knowledge and ensuring access to effective ART for HIV-positive people.

“Increased efforts must now focus on wider dissemination of this powerful message,” she said, “and ensuring that all HIV-positive people have access to testing, effective treatment, adherence support, and linkage to care to help maintain an undetectable viral load.”