Background: It is unknown what levels of preexposure prophylaxis (PrEP) use are needed to reduce racial disparities in HIV incidence among men who have sex with men (MSM). Using an agent-based model, we quantified the impact of achieving PrEP coverage targets grounded in equity on racial disparities in HIV incidence among MSM in an urban setting in the Southeastern United States.
Methods: An agent-based model was adapted to simulate HIV transmission in a network of Black/African American and White MSM aged 18-39 years in the Atlanta-Sandy Springs-Roswell metropolitan area over 10 years (2015-2024). Scenarios simulated coverage levels consistent with targets based on the ratio of the number of individuals using PrEP to the number of individuals newly diagnosed in a calendar year (i.e., the 'PrEP-to-need ratio'), ranging from 1 to 10. Incidence rate ratios and differences were calculated as measures of disparities.
Results: Without PrEP, the model predicted a rate ratio of 3.82 and a rate difference of 4.50 comparing HIV incidence in Black/African American and White MSM, respectively. Decreases in the rate ratio of at least 50% and in the rate difference of at least 75% were observed in all scenarios in which the PrEP-to-need ratio among Black/African American MSM was 10, regardless of the value among White MSM.
Conclusion: Significant increases in PrEP use are needed among Black/African American MSM to reduce racial disparities in HIV incidence. PrEP expansion must be coupled with structural interventions to address vulnerability to HIV infection among Black/African American MSM.