Sexual orientation was associated with intention to be vaccinated with a smallpox vaccine against mpox: A cross-sectional preliminary survey in Japan.

This survey aimed to assess the prevalence of intention to receive smallpox vaccine against mpox and its relationship with sexual orientation in Japan. A cross-sectional online survey was conducted in September-October 2022, with 12,900 assigned males and 13,413 assigned females participating. Modified Poisson regression analyses were performed to determine the relationship between vaccine willingness and sexual orientation, adjusting for socioeconomics, trust in government, COVID-19 vaccination status, and frequency of brothel visits. Vaccine willingness was higher in homosexual respondents than heterosexual counterparts, with proportions of 23.1 % among assigned males and 13.4 % among assigned females. Homosexual orientation was significantly associated with vaccine willingness, with prevalence ratios of 1.37 (95 % CI: 1.23-1.54) among assigned males and 1.34 (95 % CI: 1.13-1.59) among assigned females. These findings highlight the need for targeted vaccine promotion campaigns and ongoing monitoring of attitudes towards mpox and vaccine compliance in high-risk groups.