An ongoing dialogue on HIV/AIDS, infectious diseases,
May 27th, 2010
HIV Treatment is Prevention!
The Lancet has just published a large prospective study demonstrating the protective effect of HIV treatment on the risk of viral transmission:
3381 couples were eligible for analysis … Only one of 103 genetically-linked HIV-1 transmissions was from an infected participant who had started ART, corresponding to transmission rates of 0·37 (95% CI 0·09—2·04) per 100 person-years in those who had initiated treatment and 2·24 (1·84—2·72) per 100 person-years in those who had not—a 92% reduction (adjusted incidence rate ratio 0·08, 95% CI 0·00—0·57, p=0·004).
A similar observation was made in an earlier study presented at CROI 2009, not yet published. Astoundingly, the rate of transmission in this Lancet paper could have been be zero if analyses were limited only to those with undetectable viral loads on treatment.
So here’s the bottom line: HIV treatment dramatically, hugely, ginormously reduces the risk of HIV transmission.
(My daughter several years ago predicted that ginormous would become a word. She was right.)
Yes, we can quibble with some of the details — the 2009 study did not include viral load measurements, this one in the Lancet was actually part of a study of HSV treatment hence the results are observational, protection from infection is not 100% — but is there any doubt that HIV treatment is currently our most effective way of preventing the spread of HIV?
Some will say that the definitive study on this issue is HPTN 052, which randomizes the HIV-infected member of a serodiscordant couple to go on treatment or to wait until the CD4 cell count drops below 250. The primary endpoint is the rate of infection among the seronegative partners.
But that study is likely to exclude those most likely to transmit HIV, since it’s limited to people with HIV who have no symptoms, a relatively high CD4 cell count, and hence on average a lower viral burden.
At this point, it seems a no-brainer to me. Treatment is prevention.
4 Responses to “HIV Treatment is Prevention!”
Paul E. Sax, MD
Associate Editor
NEJM Clinician
Biography | Disclosures & Summaries
Learn more about HIV and ID Observations.
FROM NEJM — Recent Infectious Disease Articles- A Matter of Time February 5, 2026A 29-year-old woman with active opioid, alcohol, benzodiazepine, tobacco, and cocaine use disorders and recent intravenous drug use presented with acute onset of chills and increased pain and drainage of chronic wounds in both legs.
- Antigenic Drift and Antivaccine Shift in the 2025–2026 Influenza Season February 4, 2026Both viral and host factors have contributed to the intensity of influenza activity during the 2025–2026 season. Some of these factors can be managed, whereas others are largely beyond human control.
- Case 4-2026: An 80-Year-Old Woman with Cough and Hypoxemia January 29, 2026An 80-year-old woman was admitted to the hospital because of cough and hypoxemia (oxygen saturation, 83%). CT of the chest showed diffuse ground-glass opacities in both lungs. A diagnosis was made.
- The Essential Role of States in Protecting Immunization Access January 29, 2026In the face of U.S. federal policy shifts that threaten to destabilize vaccine access and weaken clinical guidance, states can step in and protect their residents.
- A New Therapeutic Broadcast on Hepatitis D, a Satellite Virus January 22, 2026Hepatitis D virus (HDV) is known as a satellite virus because it requires the hepatitis B virus (HBV) surface antigen (HBsAg) to enter the hepatocytes and to complete its life cycle. HDV is the smallest human pathogen, with a single-stranded RNA genome that is approximately 1.7 kb long. Yet, chronic...
- A Matter of Time February 5, 2026
This is revolutionary discovery that can extinguish the epidemic if we can provide cheap, instant rapid accurate self-administered ID of new HIV infection along with 24/7 cheap access to first line therapy.
Yep. Big ifs there, I acknowledge.
But something like this seems to be happening within certain communities — MSM in San Francisco and injection drug users in Vancouver. With a higher proportion on treatment, there’s a suggestion that incidence is declining.
In our clinic here in Nigeria, we have experienced 100% success rates in prevention of transmission in serodiscordant couples who want to get pregnant without access to high tech methods. We just advocate the couple to wait till infected partner has an undetectable viral load and they have unprotected sex or with the condom slit at the tip during the woman’s fertile period. If only we can assure cheap, properly monitored undisrupted treatment…
I appreciate your highlighting this important study. It is my sense that people who successfully access and sustain treatment with ART are different in many ways. I advocate for universal access to care and ART is part of that, but I wonder if the results will be sustained with all persons–I hope so, but I wonder.