Taking anti-HIV drugs stops gay men passing on the virus to sexual partners, a study published in the Lancet has found.
The study of 972 gay male couples where one was living with HIV and taking antiretroviral therapy (ART) and the other was HIV negative over eight years, from 2010-2017, found no evidence of transmission. This was due to treatment reducing the virus to very low levels in the body.
‘Unlike other studies on HIV transmission, we only recruited couples that had already chosen not to use condoms and in the primary analysis we only included periods when condoms were not used and with no use of PrEP or PEP by the HIV-negative partner,’ the study’s authors commented.
‘We found no linked transmissions across all types of sexual behaviour and during periods when the HIV-positive or HIV-negative partner reported an STI.’
The researchers say that around 472 cases of HIV are likely to have been prevented. In total, the couples reported having sex without condoms a total of 76,088 times. Although 15 men did become infected with HIV during the study, genetic testing showed that none of the viruses came from their main partner.
‘Our findings provide conclusive evidence that the risk of HIV transmission through anal sex when HIV viral load is suppressed is effectively zero,’ conclude the researchers. ‘Among the 782 serodifferent gay couples followed for almost 1600 eligible couple-years of follow-up, which included more than 76 000 reports of condomless sex, we found zero cases of within-couple HIV transmission.’