Aids breakthrough as study finds drugs stop HIV transmission
Virus cannot be passed on through sexual contact if infected partner takes antiretroviral drugs
Treatment with antiretroviral drugs reduced the risk of sexual transmission of the virus that causes Aids to zero, a groundbreaking study of nearly 1,000 gay male couples showed.
The finding has been hailed as signalling a prospective end to the Aids pandemic, suggesting the disease, which has killed more than 35m people since it was first identified in the early 1980s, can no longer be passed on through unprotected sexual contact provided the infected partner is taking medicine to suppress HIV.
The researchers said their results provided a similar level of evidence on viral suppression and HIV transmission risk for gay men to that previously generated for heterosexual couples, and suggested that the risk of HIV transmission in gay couples through condomless sex when the viral load is suppressed by the drugs is effectively zero.
The observational study, which is the largest of its kind and published in The Lancet on Thursday, provides “conclusive evidence” that proper antiretroviral treatment will ensure the virus is “untransmittible”, the researchers said.
The effectiveness of HIV medication means that many people with the virus are already living lives at least as long as peers who do not suffer from it, a sharp medical and societal shift from the era in which it was seen as a near-certain death sentence.
Alison Rodger, a professor at University College London who co-led the research, said: “Our findings provide conclusive evidence for gay men that the risk of HIV transmission with suppressive ART [antiretroviral therapy] is zero.”
She added: “This powerful message can help end the HIV pandemic by preventing HIV transmission, and tackling the stigma and discrimination that many people with HIV face.
“Increased efforts must now focus on wider dissemination of this powerful message 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.”
Over eight years of follow-up in the study, 15 HIV-negative men became infected with HIV, but none of the viruses screened in the newly infected partner was genetically linked to the HIV virus that had infected their main partners, ruling out any within-couple HIV transmissions.
Underlining the human impact of the study’s findings, the researchers estimate that effective antiretroviral therapy prevented about 472 HIV transmissions during the eight years of the study.
The authors emphasise the importance of those infected with the virus being regularly monitored and supported to stick to their therapy over many years. They also cautioned that the effectiveness of antiretroviral treatment in preventing HIV transmission is dependent on ensuring that the virus remains undetectable in the blood.