Factors influencing the routine immunization status of children aged 2-3 years in China

OBJECTIVES: To examine the factors associated with the routine immunization status of children aged 2–3 years in China for gaining a better understanding of the Expanded Program on Immunization and to provide evidence for formulating specific strategies to guide the allocation of health resources. METHODS: We analyzed data from 45095 children aged 2–3 years in the 2013 National Immunization Coverage Survey to identify the sociodemographic and provider-associated factors affecting the full immunization status of children. Univariate and multiple logistic regression analyses were performed. RESULTS: The immunization rate for children aged 2–3 years ranged from 95.9% (diphtheria and tetanus toxoid with pertussis vaccine, 4(th) dose) to 99.5% (Japanese encephalitis vaccine, 1(st) dose) and was 93.1% for full immunization. In terms of sociodemographic factors, male children [adjusted OR (AOR): 1.115; 95% confidence interval(CI):1.016–1.222], minority children (AOR: 1.632; 95% CI: 1.457–1.828), children of fathers with less than high school education (AOR: 1.577; 95% CI: 1.195–2.081), those born at home (AOR: 4.655; 95% CI: 3.771–5.746), those who immigrated from an adjacent county (AOR: 2.006; 95% CI: 1.581–2.546), and those living in urban-rural fringe areas (AOR: 1.807; 95% CI: 1.475–2.214) or mountainous areas (AOR: 1.615; 95% CI: 1.437–1.814) had significantly increased odds of not being fully immunized. In terms of provider-associated factors, administration of vaccines at home (AOR: 2.311; 95% CI: 1.316–4.059), household reminders (AOR: 2.292; 95% CI: 1.884–2.789), and travel time to vaccination providers of >40 minutes (AOR: 1.622; 95% CI: 1.309–2.010) were negatively associated with immunization rates. In addition, compared to 3-year-old years, 2-year-old children (AOR: 1.201; 95% CI: 1.094–1.318) were less likely to be fully immunized. CONCLUSIONS: All included factors except maternal education level and distance from home to vaccination providers significantly affected immunization rates. Appropriate reminders and accessibility of immunization services played key roles in improving the immunization status. More attention to high-risk groups identified in this study may reduce the disparities in routine childhood immunization in China.