“Undetectable = Untransmittable” has been officially endorsed by many U.S. and international AIDS service organizations (ASOs), including the International AIDS Society (IAS), AIDS United, Positive Lite, Canadian AIDS Treatment Information Exchange, APLA Health, GMHC, Housing Works, Human Rights Campaign, Desmond Tutu HIV Foundation, and the National Alliance of AIDS State & Territorial Directors (NASTAD). (See the full list here.)
Many HIV activists are applauding the prevention message, while others remain skeptical. Several respected national ASOs have declined to support the U=U campaign. Many people living with HIV are not so sure what it even is and how it might affect them.
To say that an undetectable viral load makes it virtually impossible to transmit the virus during sex is a bold and powerful statement. But only 6–14% of people who are living with HIV and are on treatment believe they cannot transmit the virus, according to AIDSMAP.
In January of 2008, the Swiss National AIDS Commission issued a statement co-authored by four of the country’s experts, most notably Dr. Pietro Vernazza. It became known as the “Swiss Statement,” which reads:
“An HIV-infected person on antiretroviral therapy with completely suppressed viraemia (“effective ART”) is not sexually infectious, i.e., cannot transmit HIV through sexual contact.” It went on to say that this statement was true as long as:
- The person adheres to antiretroviral therapy, the effects of which must be evaluated regularly by the treating physician; and
- The viral load has been suppressed below the limits of detection (i.e., below 40 copies/ml for at least six months; and
- There are no other sexually transmitted infections (STIs).
Not surprisingly, there was some backlash following this statement’s release. It was considered controversial at the time and many HIV/AIDS advocates were skeptical of the data.
In 2016, final data from the HIV Prevention Trials Network (HPTN) 052 study were published by the New England Journal of Medicine (NEJM). During HPTN 052, approximately 1,736 serodiscordant (meaning that one sexual partner was HIV-negative, the other partner was HIV-positive), mostly straight couples (although there were 38 gay couples) were followed and the HIV-positive partners were given antiretroviral medications, some sooner and some later. The study took place in 18 sites in eight countries across the world.
HPTN 052 found a 93% reduction in HIV risk in those partners who had received HIV treatment earlier, rather than later. After viral suppression for six months, there were zero new infections. Dr. Myron Cohen, principal investigator for HPTN 052 and Director of the Institute for Global Health and Infectious Diseases at the University of North Carolina at Chapel Hill, was quoted as saying, “The HPTN 052 study confirms the urgent need to treat people for HIV infection as soon as it is diagnosed to protect their health and for public health.”
On July 12, 2016, data from the PARTNER study were released in the Journal of the American Medical Association (JAMA). This study looked at 888 serodiscordant couples (38% of them were gay male couples, the rest were heterosexual), in 75 clinics in 14 European countries. The PARTNER study tracked 58,213 condomless sex acts (both anal and vaginal). Again, the HIV-positive sexual partner was on antiretroviral therapy for at least six months—and the study showed zero linked transmissions yet again. However, there were eleven new HIV infections among the HIV-negative partners, 10 in gay men and one in a straight couple. But these were not linked infections, and eight of the 11 participants reported that they had recent condomless sex with someone outside their main relationship.
And as this article was being written, new data were presented at the International AIDS Society Conference (IAS) 2017 in Paris. Opposites Attract, a study of serodiscordant MSM (men who have sex with men), took place in Australia, Brazil, and Thailand. More than 12,000 condomless anal sex acts were recorded among 343 couples. No linked HIV transmissions occurred when the HIV-negative partner was only protected by his HIV-partner’s undetectable viral load.
But what exactly are “linked transmissions” in the context of a study? According to Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases (NIAID), linked transmissions are those infections that are known to come from “regular sexual partners through genotypic tests…unlinked infections are not from the same person.” Basically, study scientists run genotypic tests that can show whose virus came from whom.
Groundbreaking prevention campaign takes the world by storm.