Oral PrEP programs for HIV prevention continue to face the challenges of low adherence and high dropout rates. Injectable PrEP could help overcome some of these challenges. We used a dynamic compartmental model to estimate HIV incidence and cost outcomes in the United States from 2022 to 2031 for different portions of people initiating and re-initiating PrEP using injectable versus oral PrEP starting with its introduction in 2022. The model included two levels of adherence, which affected cost and effectiveness of PrEP. We assumed lower dropout rates, higher annual costs, and higher efficacy for injectable PrEP compared with oral PrEP. Our results showed that the scenarios with increasingly higher injectable PrEP versus oral PrEP uptake resulted in more people on PrEP overall, fewer new HIV infections, higher PrEP spending, and lower HIV treatment and care spending.
