In recent years, an overwhelming body of clinical evidence has firmly established the HIV Undetectable = Untransmittable (U=U) concept as scientifically sound, say officials from the National Institutes of Health. U=U means that people living with HIV who achieve and maintain an undetectable viral load – the amount of HIV in the blood – by taking and adhering to antiretroviral therapy (ART) as prescribed cannot sexually transmit the virus to others.
Officials from NIH’s National Institute of Allergy and Infectious Diseases (NIAID) review the scientific evidence underlying U=U and discuss the implications of widespread acceptance of the message.
In the new commentary, NIAID director, Dr Anthony S Fauci, and colleagues summarise results from large clinical trials and cohort studies validating U=U. The landmark NIH-funded HPTN 052 clinical trial showed that no linked HIV transmissions occurred among HIV sero-different heterosexual couples when the partner living with HIV had a durably suppressed viral load. Subsequently, the PARTNER and Opposites Attract studies confirmed these findings and extended them to male-male couples.
Validation of the HIV treatment as prevention strategy and acceptance of the U=U concept as scientifically sound have numerous behavioural, social and legal implications, the NIAID officials note. U=U can help control the HIV pandemic by preventing HIV transmission, and it can reduce the stigma that many people with HIV face.
The success of U=U as an HIV prevention method depends on achieving and maintaining an undetectable viral load by taking ART daily as prescribed. Numerous factors, including lack of access to quality health care, can make ART adherence difficult. To enhance the overall success of U=U, the authors emphasise the importance of implementing programmes that help patients remain in care and address the barriers to daily therapy.
Even though the clinical data underpinning the concept of U = U have been accumulating for well over a decade, it is only recently that an overwhelming body of evidence has emerged to provide the firm basis to now accept this concept as scientifically sound. This has important implications in several areas. The U = U concept provides incentives for individuals with HIV to seek, initiate, and adhere to ART. In addition, it adds incentives to efforts to control and ultimately end the HIV/AIDS pandemic because treatment as prevention is a critical tool in preventing the spread of HIV infection.2 The U = U concept also bridges the best of biomedical science with current concepts in behavioral and social science by removing the sense of fear and guilt that a person may be harming someone else, as well as the feeling of self-imposed and external stigma that many people with HIV experience. Finally, this concept has legal implications related to the criminalization of certain persons with HIV whereby criminal law is used to penalize alleged, perceived, or potential HIV exposure of one person to another.
Robert W Eisinger, Carl W Dieffenbach, Anthony S Fauci