Zero-Dose Vaccination of Self-Paid Vaccines Among Migrant and Left-Behind Children in China: Evidence from Zhejiang and Henan Provinces

Background/Objectives: As zero-dose vaccination has become a global health concern, understanding the practice of self-paid immunizations in migrant and left-behind children in China is crucial to the prevention and control of infectious diseases. Methods: A cross-sectional study was conducted in 1648 children and their caregivers in urban areas in Zhejiang Province and rural areas in Henan Province. The participants were then classified into four groups: urban local, migrant, non-left-behind, and left-behind. Results: Compared to urban local children, migrant (prevalence ratios: 1.29, 95% confidence intervals: 0.69–2.41), non-left-behind (4.72, 3.02–7.37), and left-behind (4.79, 3.03–7.56) children were more likely to be zero-dose vaccinated. Children aged 1–2 years (odds ratio: 1.60, 95% confidence intervals: 1.14–2.23) and born later (1.55, 1.12–2.14), with caregivers aged >35 years (1.49, 1.03–2.15) and less educated (elementary school or lower: 4.22, 2.39–7.45) were less likely to receive self-paid vaccinations, while caregivers other than parents (0.62, 0.41–0.94) and lower household income (0.67, 0.49–0.90) lowered the likelihood of zero-dose vaccination of self-paid vaccines. For migrant and rural zero-dose children, the majority of caregivers reported they “didn’t know where to get a vaccination”, with responses ranging from 82.3% to 93.8%. Conclusions: Migrant and rural children should be prioritized in the promotion of self-paid immunization in order to accomplish the WHO Immunization Agenda 2030’s goal of “leaving no one behind”.