The determinants of vaccine hesitancy in China: A cross-sectional study following the Changchun Changsheng vaccine incident.

Introduction: Vaccine hesitancy is cited as one of the top threats to global health. The Changchun Changsheng Biotechnology Company was found to have violated good manufacturing practices in July 2018, leading to widespread distribution of sub-potent vaccines in China. We estimated the prevalence and determinants of vaccine hesitancy following the Changchun Changsheng vaccine incident (CCVI).

Methods: We conducted a cross-sectional survey in China in January 2019, and 2,124 caregivers of children < 6 years old completed self-administered questionnaires. Multinomial logistic regression was used to assess the determinants of vaccine hesitancy; the potential determinants included demographics, socioeconomic status, vaccine confidence, and knowledge of the CCVI. Adjusted Odds Ratios (AORs) and 95% confidence intervals (CI) are reported.

Results: Around 89% of caregivers had heard of the CCVI. Although 83% and 88% of caregivers agreed that vaccines are safe and effective, respectively, 60% expressed some hesitancy about vaccination. Of those hesitant, 26% vaccinated their children at times with doubts, 31% delayed vaccination and 3% refused specific vaccines. Multinomial regression analysis showed that confidence in vaccine safety was associated with a reduced odds of doubts on vaccination (AOR = 0.64; 95%CI = 0.44-0.94), whereas caregivers who had heard of the CCVI had a significantly higher odds of doubts on vaccination (AOR = 1.61; 95%CI = 1.05-2.45). Confidence in the vaccine delivery system and government were associated with a lower odds of vaccine hesitancy. Caregivers with higher education and Buddhism or other religions were significantly more hesitant to vaccinate their children.

Conclusion: Vaccine hesitancy was prevalent following the CCVI. Over half the caregivers either accepted childhood vaccination with doubts or delayed vaccines; only a small number were active refusers. Our findings highlight the importance of addressing vaccine hesitancy, especially following vaccine incidents. Tailored communications are needed to reduce vaccine hesitancy, especially among the highly educated and Buddhist caregivers.