Willingness to accept the HBV vaccine and related factors: Administering the vaccination attitudes examination scale to Urban Vietnamese adults.

Vietnam has low hepatitis B vaccination coverage among adults, posing a threat to the healthcare system. To mitigate negative impacts, it is essential to identify vaccine hesitancy and refusal levels and their sociodemographic correlates. We conducted a cross-sectional survey of 926 adults in Ho Chi Minh City (January-March 2025) using a self-administered questionnaire and the Vaccination Attitudes Examination (VAX) scale. Descriptive analysis was performed, and associations between variables were explored using a chi-square test. Multinomial logistic regression identified correlates of vaccine hesitancy and refusal, statistical significance was set at p < 0.05. When analyzing general vaccine intentions regardless of vaccination status, 65.6% of participants indicated acceptance, 19.3% hesitancy, and 15.1% refusal. The overall Cronbach's alpha was 0.833 (range = 0.812-0.919), and the McDonald's omega coefficients ranged from 0.820 to 0.920. The uniqueness values (0.115-0.422) indicated that substantial variances were explained by latent factors, with significant unstandardized loadings of 0.94 to 1.31 (p < 0.001). A unique "knowledge paradox" was identified: poor knowledge about the HBV vaccine predicted outright refusal (AOR = 2.42), whereas higher factual knowledge was positively correlated with mistrust of vaccine benefits (r = 0.23, p < 0.01), worries about future effects (r = 0.19, p < 0.01), and total VAX scores (r = 0.19, p < 0.01). This suggests that limited knowledge contribute to refusal, while greater factual knowledge coexisting with "informed skepticism" or cautious hesitancy. Vaccine refusal was primarily associated with a preference for natural immunity, while mistrust of vaccine benefits and commercial concerns were specifically linked to increased hesitancy. The VAX scale serves as a reliable instrument for assessing vaccine attitudes among urban Vietnamese adults. It helps identify key vaccine-related concerns and supports continuous monitoring of public attitudes, which is essential for designing effective vaccination programs and enhancing public trust in vaccines.