On Call: A Doctor's Journey in Public Service

by Anthony Fauci

A study involving both gay and heterosexual couples titled “PARTNER” partially answered that question, which was fully answered by the PARTNER2 study involving eight hundred only-gay men who had condomless sex more than seventy-seven thousand times without a single case of “linked” transmission. Linked transmission is when examination of the virus in both subjects shows that individual A clearly passed the virus to individual B. These results, which were presented at the 2018 International AIDS Conference in Amsterdam, firmly established that when the virus was suppressed by antiretroviral therapy to below detectable levels, it completely eliminated the possibility that the person with HIV would pass the infection on to a sexual partner without HIV. The activist community designated this phenomenon as “undetectable equals untransmittable,” or U = U. These extraordinary drugs not only saved the life of the person with HIV but also prevented the further transmission of the virus. This was a lifesaving double bonus. Another huge benefit of U = U was that it removed the stigma from a person with HIV who was properly treated because it made clear that such a person was not a danger to anyone else. Although all of this was fully realized in 2018 and beyond, it all started with the six-year study that Mike Cohen and his colleagues published in 2011. This is a classic example of the building blocks and iterative nature of science.