The role of vaccination and public awareness in medium-term forecasts of monkeypox incidence in the United Kingdom

Monkeypox virus (MPXV) is spreading rapidly through close human-to-human contact primarily amongst communities of men-who-have-sex-with-men (MSM). Behavioural change arising from increased knowledge and health warnings may decelerate the rate of transmission and Vaccinia-based vaccination is likely to be an effective longer-term intervention. Here we investigate the current epidemic within the UK population and simulate control options over a 12 week projection using a stochastic discrete-population transmission model which includes MSM status, rate of formation of new sexual partners, and an underlying random sized metapopulation structure. We find that the virus may have already infected a significant proportion of the MSM group with the highest sexual activity (32.5%; 15.9% - 44.9% prediction IQR); the associated immunity, albeit among groups that form a small but sexually active part of the MSM community in the UK, coupled to behavioural driven decrease in the transmission rate of individuals infected with monkeypox, leads to case incidence flattening and then declining over the projection period (12 weeks). Vaccination is most beneficial when targeted to MSM with highest activity if delivered in the near term to further interrupt transmission amongst those driving the epidemic.