PrEP Works in Clinical Practice

Summary and Comment |
September 11, 2015

PrEP Works in Clinical Practice

  1. Carlos del Rio, MD and
  2. Colleen F. Kelley, MD, MPH

Kaiser Permanente members who initiated PrEP had no new HIV infections during 388 person-years of follow-up, despite high rates of other sexually transmitted diseases.

  1. Carlos del Rio, MD and
  2. Colleen F. Kelley, MD, MPH

In July 2012, the FDA approved use of tenofovir/FTC for pre-exposure prophylaxis (PrEP). However, uptake has been slower than desired, and little is known about effectiveness outside of clinical trials. Now, investigators at Kaiser Permanente in San Francisco have documented their experience with PrEP use by members at high risk for HIV infection who were referred to a specialized PrEP program.

Of the 1045 individuals who were referred to the program between July 2012 and February 2015, 835 were evaluated and 657 started PrEP (including 20 who discontinued use during the study period and then restarted it). PrEP initiators had a mean age of 37, and 99% were men who have sex with men; the mean duration of PrEP use was 7.2 months. Initiators were significantly more likely than noninitiators to report having multiple sex partners and prior PrEP use.

Thirty percent of the 657 PrEP initiators received a sexually transmitted disease diagnosis during the first 6 months of use, and 50% received one during the first year. However, there were no new HIV diagnoses over the 388 person-years of follow-up. Among the 143 initiators who reported on their sexual behavior, 74% stated that their number of sexual partners was unchanged.


This specialized PrEP program within an integrated healthcare system has shown excellent results: a significant increase in PrEP use — and no new HIV infections — in a group of high-risk individuals. Although adherence data were not provided, adherence was sufficient for effectiveness. These data add to the increasing body of research suggesting that PrEP works and that its scale-up as an HIV-prevention intervention should not wait any longer.

Dr. Kelley is Assistant Professor of Medicine in the Division of Infectious Diseases at Emory University.

Note to readers: At the time NEJM Journal Watch reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.

Editor Disclosures at Time of Publication

  • Disclosures for Carlos del Rio, MD at time of publication Consultant / Advisory board InnaVirVax Grant / Research support National Institutes of Health (NIH); NIH/National Institute of Allergy and Infectious Diseases; Centers for Disease Control and Prevention; NIH/National Institute on Drug Abuse; Addis Ababa University Editorial boards AIDS Research and Human Retroviruses; Journal of AIDS Leadership positions in professional societies HIV Medicine Association (Board of Directors); International Antiviral Society–USA (Board of Directors)


Reader Comments (1)

PEDRO CARNEIRO Physician, Infectious Disease, Brazil

What was the definition of "high risk for HIV infection"? And what about adverse reactions? PrEP is probably na important strategy for preventing new HIV cases, and it's use must be encouraged with more information.

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