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.