Mpox diagnosis history, behavioural risk modification, and vaccination uptake in gay, bisexual, and other men who have sex with men in the UK: findings from a large, online community cross-sectional survey (RiiSH-Mpox) undertaken November/December 2022.

Mpox cases, first identified as part of the multi-country outbreak in May 2022, rapidly fell in the UK from September 2022. Public health responses included community-coordinated messaging and a targeted mpox vaccination in eligible gay, bisexual, and other men who have sex with men (GBMSM). Using data from an online, community survey of GBMSM (November/December 2022), we examined self-reported mpox diagnoses, behavioural risk modification, and mpox vaccination offer and uptake (≥1 dose). Thirty-five participants (2.6%, 35/1,333) were ever mpox test positive; half (53%, 707/1,333) reported behaviour modification to avoid mpox. In GBMSM considered vaccine eligible, uptake was 69% (95% CI: 65%-72%, 601/875) or 92% (95% CI: 89%-94%, 601/655) in those eligible and offered. GBMSM self-identifying as bisexual, those with lower educational qualifications, and those unemployed were less likely to be vaccinated. Equitable mpox vaccine offer and provision is needed to minimise the risk of future outbreaks and mpox-related health inequalities.