Abstract Body

The Ending the HIV Epidemic (EHE) initiative aims to reduce HIV incidence in the US by 90% over a decade. Pre-exposure prophylaxis (PrEP) is a key component in this effort. Long-acting injectable (LAI) PrEP reduces the risk of HIV acquisition more than oral PrEP but its potential to impact local HIV epidemics remains unclear.

The Johns Hopkins HIV Economic Epidemiological model (JHEEM) is a dynamic model of HIV transmission in 32 high priority urban areas in the US. We leveraged JHEEM to project the incidence of HIV among men who have sex with men (MSM) from 2020-2030 under a range of interventions aimed at increasing PrEP use. In each of the 32 cities, we ran 1000 simulations testing an expansion of PrEP uptake to 10% above baseline levels of oral PrEP (either all oral PrEP, all LAI PrEP, or 50% oral + 50% LAI) as well as an expansion to 25% above baseline (all oral, all LAI, or 50% oral + 50% LAI). Interventions began in 2023 and scaled up over five years (fully implemented in 2027). Across simulations, we varied the efficacy and rates of discontinuation of oral PrEP and relative efficacy of LAI vs oral PrEP according to published estimates. We allowed the rates of discontinuation of LAI PrEP to range from 25-100% of the rate of oral PrEP discontinuation.

In the absence of any intervention, baseline-levels of oral PrEP uptake ranged from 6% in Sacramento to 25% in New York in 2020. This led to a projected reduction in HIV incidence of 19% (95% Credible Interval [CrI] 1-36%) among MSM from 2020-2030 across all 32 cities. At 10% additional PrEP uptake, the reduction in incidence across all 32 cities ranged from 33% (95% CrI 18-47%) with all oral PrEP to 37% (95% CrI 23-50%) with all LAI PrEP. At 25% additional uptake, incidence reductions ranged from 50% (95% CrI 38-60% – all oral) to 55% (95% CrI 45-65% – all LAI). There was substantial variation between cities (see Table): at 25% uptake (50/50 oral, LAI), reductions in incidence ranged from 38% in Atlanta to 67% in Seattle.

The greatest potential impact of LAI PrEP is in expansion of total PrEP uptake in conjunction with oral PrEP. If availability of LAI PrEP can increase overall PrEP uptake by 25%, substantial reductions in HIV incidence can be achieved in key populations at the local level within 10 years. Nevertheless, availability of LAI PrEP alone without improvements in the HIV continuum of care is unlikely achieve reductions in line with EHE goals.