Bridging the intention‒behavior gap in herpes zoster vaccination: A nationwide survey in a self-payment setting

Herpes zoster (HZ) causes substantial morbidity, yet global uptake remains suboptimal where the vaccine is excluded from universal coverage. Taiwan exemplifies such a self-payment setting, with the HZ vaccine self-financed and local government subsidies restricted to limited eligible groups. This study analyzed data from a nationwide, web-based cross-sectional survey of adults aged ≥18y fielded in 2025, examining factors associated with HZ vaccination behavior, intention, and willingness to pay (WTP). Of 1690 respondents, 281 (16.6%) were vaccinated; among 1409 unvaccinated, 1140 (80.9%) were willing to vaccinate. Factors associated with HZ vaccination included age ≥65y (OR: 1.59; 95% CI: 1.12-2.25), prior HZ infection (OR: 1.62; 1.23-2.15), prior receipt of influenza, pneumococcal, or respiratory syncytial virus (RSV) vaccines (OR: 3.32; 2.26-4.89), and awareness of local subsidy programs (OR: 2.30; 1.70-3.12). Among unvaccinated respondents, intention was most strongly associated with high concern about HZ (OR: 3.62; 2.67-4.90). When each prior vaccine was examined separately, prior receipt of self-paid RSV (OR: 5.35; 3.44-8.31) and pneumococcal vaccines (OR: 3.48; 2.54-4.75) showed stronger associations with HZ vaccination than coronavirus disease 2019 (OR: 1.50; 1.04-2.16) or influenza vaccines (OR: 1.51; 1.13-2.02). The median WTP rose stepwise across vaccination statuses (unvaccinated-unwilling: USD 8.2, unvaccinated-willing: USD 32.8, vaccinated: USD 65.6; p < .001), yet all values remained below the market price. In this self-payment setting, HZ vaccination was constrained by affordability rather than lack of motivation. Expanding coverage will require policy action on cost, while prior receipt of self-paid adult vaccines offers a clinically identifiable marker for targeted counseling.