Correlates of Mpox Vaccination among Sexual Minority Men in the United States: Sexual Behavior, Substance Use, and Main Partner Relationships.

Sexual minority men (SMM) have accounted for the majority of infections during the 2022 outbreak of the orthopox virus known as mpox (previously "monkeypox") in the US. This study examined correlates of mpox vaccination. Between July 28 and September 22, 2022, adult cisgender SMM ( = 2,620) not previously diagnosed with mpox responded to recruitment advertisements on social networking applications and completed an online survey. Of these, 730 (27.9%) received at least one vaccine dose. Logistic regression indicated sex with a casual partner was positively associated with vaccination. Stimulant drug use was negatively associated with vaccination; meanwhile, the use of ecstasy, ketamine, gamma-hydroxybutyrate (GHB) or psychedelics was positively associated with vaccination. Among partnered SMM, non-monogamous sexual agreements, relationship length of ≥2 years, and relationship functioning were positively associated with vaccination. Even at low levels of relationship functioning, SMM in non-monogamous relationships of ≥2 years were more likely to be vaccinated than single SMM. At very high levels of relationship functioning, partnered SMM were more likely to be vaccinated than single SMM regardless of sexual agreement or relationship length. Findings are discussed in relation to prior research on HIV, other STI prevention, and theories of dyadic functioning and health in this population.