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 survey (riish-mpox) undertaken december 2022

Introduction

In response to the 2022 Mpox outbreak, targeted vaccination was offered to GBMSM at increased risk. We determined the uptake of Mpox vaccination among a community sample of GBMSM in the UK.

Methods

An online cross-sectional survey was deployed in December 2022 to examine Mpox diagnoses and vaccination uptake among a community sample of GBMSM in the UK. We describe Mpox diagnosis history (%, 95% CI) based on self-report of a positive Mpox test and self-reported behavioural risk modification to avoid Mpox infection from May 2022 through survey completion. Bivariate and multivariable logistic regression was used to assess sociodemographic, clinical, and behavioural characteristics associated with Mpox vaccination.

Results

Of 1,333 participants (median age 45 years [IQR: 35–55]; 92% White ethnicity), 2.6% (1.8%-3.6%; 35/1,333) had an Mpox diagnosis history. Half (53%; 707/1,333) reported behavioural risk modification measure(s), the most common being a reduction in number of sex partners (38%; 510/1,333). Vaccination uptake (>1 dose) was 52% (49%-55%; 692/1,333) among all participants, and 69% (65%-72%; 601/875) in those eligible. Among all participants, bisexual men (aOR: 0.43 [0.29–0.62] vs gay men), those with qualifications below degree-level (0.49 [0.39–0.62] vs degree-level), and those unemployed (0.59 [0.43–0.80]) were less likely to report Mpox vaccination, while those reporting either multiple sex partners (≥10 recent male sex partners [7.56 (4.95–11.6) vs 1 partner], PrEP use in the last year [7.11 (5.50–9.18)], or recent STI test positivity [4.06 (2.67–6.19)]) were more likely to report Mpox vaccination.

Discussion

While high Mpox vaccine uptake in those eligible and adoption of risk modification measures likely led to the reduction of Mpox incidence in July 2022, the contribution of each is unclear. To reduce the likelihood of any future Mpox outbreaks, provision of first Mpox vaccination doses and completion of the course of vaccination in those who have received their first dose must be prioritised.