Analysis of public vaccination behavior, recommendation willingness, and influencing factors for non-National Immunization Program vaccinesin three provinces and one municipality of China

Objective To analyze non-National Immunization Program (non-NIP) vaccination behavior, willingness to recommend, and influencing factors among Chinese adults over the past two years, with the aim of providing empirical evidence to inform strategies for expanding vaccine coverage and improving public health.Methods In 2024, a questionnaire survey was conducted in four regions representing eastern, central, and western China—Shandong Province, Anhui Province, Gansu Province, and Shanghai Municipality. Using stratified sampling, 4,000 permanent residents aged 18 years and older were selected. The survey collected demographic information and non‑NIP vaccination behavior during the past two years. Willingness to recommend non‑NIP vaccination for adults aged 18–60 and seniors aged ≥60, along with related influencing factors, were also assessed. Data were analyzed using SPSS software, including descriptive statistics, t-tests, ANOVA, chi-square tests, binary logistic regression, and multivariate linear regression analyses.Results A total of 4,105 valid questionnaires were obtained. Both non‑NIP vaccination rates and recommendation willingness among the public were found to be at moderately low levels overall. Multivariate regression demonstrated that, compared to individuals who trusted vaccination-clinic staff, those who trusted official media (OR=0.689), recommendations from relatives/friends (OR=0.777), hospital doctors (OR=0.565), and non‑official media (OR=0.351) had significantly lower likelihood of being vaccinated. Higher price acceptance was positively associated with vaccination behavior, with odds ratios of 1.55, 1.95, 2.46, and 2.78 for accepting prices of 1-3, 4-6, 7-9, and all vaccines, respectively. Compared to trust in clinic staff, trusting official media (B=-0.182), relatives/friends (B=-0.450), and non‑official media (B=-0.856) were significantly associated with lower recommendation willingness scores. Price acceptance levels—accepting all vaccines, 7-9 vaccines, 4-6 vaccines, and 1-3 vaccines—were associated with higher recommendation willingness scores by 0.786, 0.650, 0.425, and 0.261 points respectively, compared to those who did not accept any. Additionally, individuals willing to pay extra service fees of 70–99 RMB (B=0.130, P=0.005) or ≥100 RMB (B=0.266, P=0.002) had significantly stronger recommendation willingness than those willing to pay only up to 20 RMB.Conclusion In this survey, both the uptake and recommendation willingness for non‑NIP vaccines remain at moderately low levels, constrained primarily by trust in information channels and price acceptance. Lower-trust sources and cost sensitivity notably suppress individual and collective vaccination and recommendation behaviors. To enhance vaccine coverage, it is essential to strengthen professional communication through authoritative channels such as vaccination clinics, and to develop rational pricing strategies and extra-service models that meet public health needs, thereby promoting immunization equity and national health objectives.