A WeChat-delivered Information-Motivation-Behavioral skills intervention to improve HPV vaccine acceptability among Chinese gay, bisexual, and other men who have sex with men.

Culturally appropriate strategies are urgently needed to promote human papillomavirus (HPV) vaccination among Chinese gay, bisexual, and other men who have sex with men. WeChat-based interventions guided by the Information - Motivation - Behavioral Skills (IMB) model offer a theory-driven approach by targeting knowledge, motivation, social norms, and self-efficacy. To evaluate a WeChat-delivered IMB-based intervention designed to improve HPV vaccine acceptability in this population. HPV vaccine acceptability and IMB constructs were assessed at baseline (T0), immediately post-intervention (T1), and 1 month post-intervention (T2). Intervention effects were estimated using generalized estimating equations. Mediation was examined using Hayes' PROCESS macro (Model 4) based on change scores with bootstrapped confidence intervals (CIs). The intervention group reported significantly higher HPV vaccine acceptability at T1 (β = 0.42, 95% CI [0.17, 0.68]; p < .001), although effects attenuated at T2 (β = 0.28, 95% CI [0.00, 0.56]; p = .05). Within the intervention group, mean acceptability increased from 3.31 at T0 to 3.86 at T1, representing a 16.6% increase. Significant improvements were also observed at T1 in HPV knowledge, perceived severity, perceived effectiveness, anticipated regret, subjective norms, and self-efficacy, with partial declines observed at T2. Mediation analyses identified knowledge (β = 0.357, 95% CI [0.228, 0.487]), subjective norms (β = 0.356, 95% CI [0.288, 0.425]), and self-efficacy (β = 0.324, 95% CI [0.244, 0.405]) as key mediators of intervention effects. WeChat-delivered IMB intervention improved short-term HPV vaccine acceptability. Sustaining these effects will require additional strategies to ensure long-term sustainability.Clinical Trial Registration: ChiCTR2400089627.