Pre-Exposure Prophylaxis (PrEP)
What is PrEP?
The term Pre-Exposure Prophylaxis (PrEP) refers to an HIV prevention concept in which persons not infected with HIV who are at high risk of the disease are take antiretroviral medication in an attempt to lower their chances of becoming infected if they are exposed to HIV.
PrEP is still the subject of on-going research efforts. Studies have indicated PrEP may offer an effective prevention strategy for men who have sex with men (MSM) and sero-discordant heterosexual men and women. Many believe the use of PrEP has the potential to dramatically change the course of the disease.
However, PrEP is also the subject of a current and evolving policy debate in HIV.
There are concerns about the ability for the already strained U.S. health systems to provide for widespread PrEP use. Public programs such as Medicaid and ADAP have faced significant budget constraints in recent years, and left many HIV patients without the ability to access their medications. It is difficult to advocate for coverage of medication regimens for those who are not infected with the disease, while many who are infected are not being provided for medically.
Another subject of debate has to do with the fact that some scientists have expressed concerns about the potential for viral resistance to develop as a result of widespread PrEP use among uninfected individuals. Viral resistance has been seen in many diseases in recent years. There is concern about the possible loss of a treatment that is currently known to be effective against the disease.
In November 2010, the National Institutes of Health (NIH) announced the results of the iPrEx clinical trial, a large, multi-country research study examining PrEP. The study found that PrEP provided additional protection to men who have sex with men (MSM) who also received a comprehensive package of prevention services that included monthly HIV testing, condom provision, and management of other sexually transmitted infections.
A separate trial by the University of Washington, called Partners PrEP, demonstrated significantly reduced HIV transmission among serodiscordant couples, in which one partner is infected with HIV and the other is not.
In July 2011, Centers for Disease Control and Prevention (CDC) completed a study called TDF2, conducted in partnership with the Botswana Ministry of Health, provided evidence that PrEP use reduced the risk of acquiring HIV infection among uninfected heterosexual men and women.
Other studies are underway to evaluate whether PrEP is safe and effective in reducing HIV infection among women and injection drug users, but those results are not yet available.
The Centers for Disease Control and Prevention (CDC) are leading federal efforts to develop formal Public Health Service guidelines for PrEP.
In 2011, the CDC released interim guidance for physicians electing to prescribe PrEP among men who have sex with men (MSM). The Interim Guidance is available to providers on the Providers PrEP page of our Provider Resources Section.
On July 16, 2012 the FDA approved the first drug for PrEP use in the United States. Following that approval, on August 10, 2012, the CDC released interim guidance for clinicians considering the use of PrEP for preventing HIV infection in their heterosexually active patients. The guidance complements the PrEP recommendations released in January 2011 for MSM, but also provides guidance for heterosexually-active women and men, as well as a number of new recommendations for women of reproductive age and for couples in which one partner is HIV-positive and the other HIV-negative. View the full MMWR here.
To learn more about the clinical details of that decision, visit our Providers PrEP page under the Provider Resources section.