Exploring Parental Decision-Making on Combination Vaccines for Eligible Children in China: Analysis Based on the BeSD Framework

Abstract

Background: Vaccination is one of the most effective public health interventions and has substantially reduced childhood morbidity and mortality worldwide. As the number of recommended childhood vaccines continues to expand, immunization schedules have become increasingly complex. Combination vaccines provide an important strategy to reduce the number of injections and simplify vaccination schedules. However, uptake of combination vaccines in China remains limited. This study applies the WHO Behavioral and Social Drivers (BeSD) framework to examine the factors influencing parental willingness and uptake of combination vaccines for eligible children.Methods: A cross-sectional mixed-methods study was conducted between May and July 2025 in Suzhou and Chongqing. A total of 1,022 parents of children aged 0-24 months were recruited from community health service centers. A structured questionnaire based on the BeSD framework measured thinking and feeling (T), social processes (S), and practical issues (P) related to vaccination. Multivariable logistic regression models were used to identify factors associated with parental willingness to vaccinate (motivation) and actual uptake of combination vaccines (behavior). Results: 86.5% (884/1,022) of parents expressed willingness to vaccinate their children with combination vaccines, whereas 51.7% (528/1,022) had actually received a combination vaccine. Higher vaccine knowledge (T) was positively associated with both willingness (OR = 1.43, 95% CI: 1.28–1.59) and uptake (OR = 1.69, 95% CI: 1.53–1.87), whereas higher perceived risk of vaccines (T) was negatively associated with willingness (OR = 0.59, 95% CI: 0.49–0.71) and uptake (OR = 0.64, 95% CI: 0.57–0.73). Information accessibility and middle household income (210,000–500,000 RMB) (P) showed the strongest associations with vaccination uptake (OR = 2.49, 95% CI: 1.93–3.21; OR = 3.01, 95% CI: 1.88–4.81). Among parents who expressed willingness to vaccinate, middle household income (210,000–500,000 RMB) and greater information accessibility were associated with a higher likelihood of actual uptake. Safety concerns (48.6%) and high cost (30.4%) remained the main barriers to vaccination. When comparing vaccine types, parents generally preferred pentavalent vaccines because of broader disease coverage and fewer injections, whereas parents choosing quadrivalent vaccines more frequently cited lower cost. Parents also showed a clear preference for combination vaccines over simultaneous multiple injections. Regional differences were observed, with higher willingness and uptake in Suzhou than in Chongqing (89.7% vs. 81.1% and 56.8% vs. 43.0%, respectively). Conclusions: This study identified a clear gap between parental willingness and actual uptake of combination vaccines. Information accessibility and economic affordability emerged as important practical factors influencing the translation of willingness into vaccination behavior. Strengthening evidence-based vaccine communication and ensuring timely access to reliable vaccination information may help address safety concerns and improve parental understanding of combination vaccines. Financial subsidies or insurance coverage, along with the integration of combination vaccines into long-term immunization planning, may help reduce affordability barriers, improve immunization service efficiency, and facilitate vaccine uptake. Given the limited acceptance of simultaneous multiple injections and the strong parental preference for pentavalent vaccines, improving access to combination vaccines and accelerating the development and availability of domestically produced pentavalent vaccines may further support broader uptake in childhood immunization programs.