High coverage with delayed doses: Cross-sectional study of parental acceptance and uptake of varicella vaccination in children aged 4-12 years in Chaoyang District, Beijing.

Regional disparities exist in China's varicella vaccination policies, with Beijing's voluntary two-dose program requiring self-payment having been implemented for more than a decade. In this study, we investigated parental acceptance and vaccination patterns among 2,189 children aged 4-12 years in Beijing's Chaoyang District, where policy integration is under consideration. The results revealed high baseline vaccination willingness (81.8%), potentially increasing to 86.3% with inclusion of an immunization program. Key determinants extended beyond demographic factors and disease knowledge to include parental satisfaction with immunization services and utilization of parenting apps. Current coverage rates were 74.5% for the first dose (VarV1) versus 53.2% for the second dose (VarV2), indicating significant second-dose attrition. Primary barriers to vaccination included limited awareness of the option to vaccinate, safety concerns, and perceptions that a single dose offers sufficient protection. Notably, 58.8% of children received VarV1 later than the recommended schedule, partly due to vaccination scheduling. School-based verification requirements emerged as a critical driver of compliance. Our study provides actionable insights for immunization policy optimization. We advocate targeted communication strategies via new media platforms, such as parenting apps, to address knowledge gaps, emphasize two-dose protocols, and boost vaccine confidence. This approach fosters a cycle of tool usage, knowledge acquisition, and timely vaccination, leveraging the demonstrated synergy between app usage and vaccine knowledge in enhancing adherence.