WHO Adds 2+1+1

The 2+1+1 regimen can reduce PrEP's cost and adherence burden, yet it may not close the gap in reaching those at the center of the HIV epidemic.

a diagram of a pill

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In 2012, pre-exposure prophylaxis (PrEP) revolutionized the public health community’s response to HIV by transforming prevention methods for those most at-risk of HIV infection. PrEP is a medication taken once daily that reduces the risk of acquiring HIV through sex by 99%. However, it remains difficult to access a prescription, pay for a prescription, and to adhere to a daily medication.

There is also a racial disparity in who can access, pay for, and adhere to PrEP. According to the Centers for Disease Control and Prevention, White individuals made up 68.7% of those who received PrEP in 2016. Black individuals made up 11.2%, and Hispanic individuals 13.1%. This despite the HIV epidemic disproportionately affecting Black young gay, bisexual, and other men who have sex with men (MSM) in the South.

The requirement to use PrEP every day may also be a barrier to widespread use. Now, the World Health Organization (WHO) recommends a new dosing guideline, known as 2+1+1, “disco dosing,” or “party PrEP.” Event-driven PrEP (ED-PrEP) consists of taking two pills–a loading dose–between two and 24 hours in advance of sex, a third pill 24 hours after the first two pills, and a fourth pill 48 hours after the first two pills. ED-PrEP is effective when an isolated act of sex is involved. WHO’s recommendation is based on recent evidence from two large clinical trials.

Although the 2+1+1 regimen can reduce PrEP’s cost and adherence burden, it may not close the gap in reaching those at the center of the HIV epidemic in the United States.

“We do know that from everywhere where PrEP programmes are reaching men at scale, there is lower uptake by ethnic minorities,” says Dr. Rachel Baggaley, HIV Prevention and Testing Coordinator at the WHO’s Department of HIV and Global Hepatitis Programme. “This may reflect lack of awareness, greater stigma, and structural issues.”

There are also few prescribers in health systems serving populations in rural areas, particularly in the southeastern US.

Databyte via What’s the 2+1+1? Event-Driven Oral Pre-Exposure Prophylaxis to Prevent HIV for Men Who Have Sex with Men: Update to WHO’s Recommendation on Oral PrEP. World Health Organization, 2019.