Re-evaluating the Potential Impact of Preexposure Prophylaxis (PrEP) in Achieving HIV Elimination in the United States: Insights From Modeling.

Background: Preexposure prophylaxis (PrEP) to prevent HIV-1 acquisition is a critical component of the strategy to achieve epidemic control and elimination goals. Previous studies assessing PrEP needs have not considered people based on individualized, quantitative risk profiles, potentially overlooking opportunities to increase PrEP use among all individuals vulnerable to acquiring HIV. Method: We modeled the risk distribution of sexually acquired HIV infection based on patterns of sexual activity among sexually active adults living in the United States. We estimated the population impact of PrEP use assuming "optimal" (PrEP perfectly distributed to those at highest risk) or "suboptimal" (distributed to only 50% of highest-risk individuals) PrEP distribution. Results: The model predicts that PrEP use by 1 million and 10 million individuals would prevent ∼3400 and 13 600 sexually acquired HIV infections per year, respectively, with optimal distribution, and 2700 and 9100 infections with suboptimal distribution. In addition to men who have sex with men, heterosexual women make up a significant proportion of the optimally targeted population. Conclusions: Our model provides a framework to estimate the potential population impact of PrEP. While results vary depending on assumptions, our findings strongly suggest that increases in PrEP uptake, substantially beyond current targets, may be required to achieve epidemic elimination goals. Our findings can inform updated assessments of PrEP coverage and provider initiatives at the individual level. Assessment of HIV acquisition risk based on individual behavior rather than risk-group membership indicates the imperative for wider PrEP distribution than currently occurs.