New Treatment Could Effectively Block HIV Transmission Between Gay Men

The Opposites Attract Study, a study that examines HIV transmission among gay men, suggests that an undetectable viral load could be "completely effective" in blocking the passage of the virus to negative partners.

The study collected data for a year-and-a half from 358 gay couples from Australia, Thailand, and Brazil. Each couple consisted of HIV-positive men and their HIV-negative partners. In this study, which ran from 2012-2016, an undetectable load refers to when the HIV-positive partner is on medication to suppress the virus. The study found that these men were able to engage in anal sex with their partners without passing on the virus.

"It really does confirm that undetectable viral load is completely effective at preventing transmissions in gay couples," Andrew Grulich, a professor from the Kirby Institute and lead scientist on the study, told BuzzFeed News.

These conclusions were drawn from almost 17,000 instances in which the participants reported having anal sex without condoms. Scientists discovered that zero HIV-transmissions occurred from these encounters.

The data was also broken down to examine the number of sexual encounters in which an undetectable viral load was the only protection used. These accounted for 12,000 of the instances. In the other 5,000 accounts, the HIV-negative participants were on PrEP.

"This tells us that if an HIV-positive person gets on treatment, achieves undetectable viral load, and that can take three-to-six months, it's not immediate--they will not transmit, provided they continue to take their pills daily and see their doctor to have their viral loads monitored," Grulich said.