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Zero HIV Transmission Rate When Viral Load Suppressed

Key clinical point: Keeping HIV viral load suppressed with antiretroviral therapy can prevent transmission of the virus.

Major finding: Viral suppression with antiretroviral therapy achieves a zero transmission rate between serodiscordant gay couples.

Study details: The prospective, observational PARTNER2 study involving 782 serodiscordant gay couples.

Disclosures: The study was supported by the National Institute for Health Research, the British HIV Association, the Danish National Research Foundation, ViiV Healthcare, Gilead Sciences, Augustinus Fonden, and A P Møller Fonden. Fourteen authors declared grants, personal fees, and other support from the pharmaceutical sector.


Rodger A et al. Lancet 2019 May 2. doi: 10.1016/S0140-6736(19)30418-0.


The results of the PARTNER and PARTNER2 trials show that timely diagnosis and effective treatment can virtually eliminate the risk of HIV transmission. However, access to HIV testing and care is not always easy, and fear, stigma, homophobia, and other forces continue to limit access to HIV treatment. This study also highlights the impact of sexual relations outside the bounds of a couple’s relationship.

While the use of preexposure prophylaxis was a criterion for exclusion from this study, this intervention should also be recognized as an important part of HIV prevention. A recent survey found that men who have sex with men are more likely to trust preexposure prophylaxis for HIV prevention than antiretroviral therapy.

Dr. Myron S Cohen is from the departments of medicine, microbiology, immunology, and epidemiology, University of North Carolina at Chapel Hill, and the UNC Institute for Global Health and Infectious Diseases in Chapel Hill. These comments are adapted from an editorial (Lancet 2019, May 2. doi: 10.1016/S0140-6736[19]30701-9). Dr. Cohen reported advisory board travel fees from Merck and Gilead unrelated to this work.