Evaluating the Impact of Targeted Mpox Vaccination Scenarios stratified by HIV Status and Sexual Risk Behaviors: A Compartmental Modeling Approach

Objectives: Models of mpox outbreaks have not fully accounted for epidemiologic heterogeneity by HIV status and sexual risk behaviors. Therefore, our objectives were to develop an innovative compartmental model that accounts for these heterogeneities and to evaluate the impact of targeted vaccination scenarios in a theoretical outbreak of mpox in Washington, DC. Methods: We developed a Susceptible-Vaccinated-Exposed-Infectious-Recovered (SVEIR) compartmental model with six different risk strata accounting for sexual risk behaviors, HIV status, and CD4. We then evaluated a theoretical 6-month outbreak of mpox in Washington, DC under various targeted vaccination scenarios. From each vaccination scenario, we chose an optimal set of vaccination rates based on the number of mpox cases, severe cases, deaths, and effective reproduction number (Reff). Results: We found that vaccinating 25% of individuals with high sexual risk behaviors was optimal. If vaccination is introduced immediately, this scenario resulted in only 316 mpox cases, no deaths, an Reff of 1.69 at the end of the 6-month period, and only required vaccinating 9,090 individuals. Conclusions: In order to control future mpox outbreaks, vaccination campaigns should target individuals with high sexual risk behaviors and be implemented in tandem with isolation protocols and partner reduction.