Undetectable = Untransmittable Reconfirmed by New Study, Embraced at IAS 2017

A newly completed study of 358 serodiscordant gay couples has not found a single case of HIV transmission in 16,889 acts of condomless anal sex. The Opposites Attract study, conducted by the Kirby Institute at UNSW, Sydney, made its report to the 9th International AIDS Society Conference on HIV Science (IAS 2017) in Paris, France, in July 2017.

Opposites Attract has shown that HIV-positive men who have achieved an undetectable viral load via effective treatment do not transmit HIV to their partners. It is the largest study to date to analyze HIV transmission risk among homosexual couples with differing HIV status. Researchers recruited and followed-up gay couples at clinics in Australia, Bangkok, Thailand, and Rio de Janeiro, Brazil.

The evidence from Opposites Attract adds to the findings of the PARTNER study: HIV-positive people on effective HIV treatment that fully suppresses their virus cannot transmit their infection through sex. In the PARTNER study a total of 1,238 eligible, follow-up couple-years was provided from 548 heterosexual (36,000 condomless sex acts) and 340 MSM (22,000 condomless sex acts) couples. Taken together, the two studies have not found a single case of HIV transmission in nearly 40,000 acts of condomless anal sex between gay men.

Reacting to the studies’ findings, Dr. Anthony Fauci, Director of the U.S. National Institute for Allergies and Infectious Diseases, said: “Scientists never like to use the word ‘Never’ of a possible risk. But I think in this case we can say that the risk of transmission from an HIV-positive person who takes treatment and has an undetectable viral load may be so low as to be unmeasurable, and that’s equivalent to saying they are uninfectious. It’s an unusual situation when the overwhelming evidence based in science allows us to be confident that what we are saying is fact.”

The findings lend great strength to the “U Equals U” campaign, begun by Bruce Richman, a Harvard-trained lawyer and prime force behind the Prevention Access Campaign [A&U, December 2016]. Bruce has said, “In 2006 when I was diagnosed, I was terrified of infecting someone I loved… But in 2012 when I finally started therapy, my doctor told me that if I suppressed my viral load, I would become non-infectious….”

Getting doctors and policy-makers on-board with U=U “is demolishing HIV stigma and encouraging people to start treatment and bring an end to the epidemic.” The U=U Consensus Statement was signed on to by NAM, by UNAIDS, and by the IAS at the Conference.

“This is life-changing news for couples of differing HIV status. But it is important that the HIV positive partner is under regular medical care and does not miss any of their antiretroviral medication in order to ensure they maintain an undetectable viral load” noted Professor Andrew Grulich of the Kirby Institute and chief investigator on the Opposites Attract study.

The National Health and Medical Research Council (NHMRC) funded the majority of this study, complemented by a two-year extension made possible by the Foundation for AIDS Research (amfAR), ViiV, and Gilead.

For more information on the Opposites Attract study, visit: www.oppositesattract.net.au. For more information on IAS 2017 in Paris, log on to: www.ias2017.org. For more information on the Prevention Access Campaign and “U=U,” visit: www.preventionaccess.org.