Mpox Vaccination Willingness, Concern Profiles, and Associated Factors Among Men Who Have Sex with Men in Changsha, China

Background: Mpox vaccination is an important prevention strategy for men who have sex with men (MSM), yet responses to vaccination may not be adequately captured by a simple willing-versus-unwilling framing. We examined correlates of vaccination willingness and heterogeneity within the delayed/refused responses subgroup in Changsha, China. Methods: A cross-sectional survey was conducted using respondent-driven sampling (RDS). Vaccination willingness was classified as immediate willingness versus delayed/refused responses. Analyses included cluster-robust logistic regression, RDS-weighted regression, generalized estimating equations, and a recruiter-linked network-lag model. Among respondents with delayed/refused responses, concern profiles were explored using unsupervised clustering of standardized concern items. Results: Among 405 recruited MSM without a self-reported mpox infection history, immediate willingness and delayed/refused responses were nearly equally distributed, indicating that lack of immediate willingness was common. Across primary models, ever use of pre-exposure prophylaxis (PrEP) and higher mpox-related information exposure frequency were the most consistent correlates of immediate willingness versus delayed/refused responses, whereas basic sociodemographic variables showed little evidence of independent association. Within the delayed/refused group, three partially overlapping patterns emerged: broadly elevated cross-domain concern, low-concern delay with few strongly endorsed barriers, and more selective safety- and burden-related concerns. These findings suggest that a lack of immediate willingness may arise through different psychosocial pathways rather than a single common mechanism. Conclusions: Mpox vaccination willingness among MSM in Changsha appeared to be shaped more by prevention-related behaviors and psychosocial factors than by basic sociodemographic profiles alone. Vaccination strategies may benefit from cross-topic sexual-health communication, integrated prevention efforts, and subgroup-sensitive approaches to delayed or refused willingness.