Evaluation of three control strategies to limit mpox outbreaks in an agent based model

Most of the 2022 mpox outbreaks in high income countries, which predominantly affected men who have sex with men, peaked less than two months after detection. To stop the outbreaks, people were encouraged to limit new sex partners, take up any offers for smallpox vaccination, and self-isolate. The relative contributions of each of these strategies to outbreak reduction are hard to know. To consider the potential relative efficacy of each of these measures individually, we constructed agent-based models using plausible partnership counts, reasonable behaviour choices and published information about smallpox vaccination uptake rates in the UK context during 2022. Compared to a baseline, no intervention scenario, partner reduction was more effective at preventing generation of secondary cases than the vaccine rollout at the speed that the smallpox vaccine rollout occurred in the UK in 2022. These findings suggest that partner reduction by the most affected community rather than pharmaceutical intervention was largely to credit for causing case numbers to peak as early as they did.