Understanding the predictors of vaccine hesitancy in caregivers of under-five children and impact on childhood vaccination uptake in Ondo State, Nigeria.

Routine childhood vaccination is responsible for the survival of millions of children under five years annually, with 154 million deaths averted in the past 50 years through protection from vaccine-preventable diseases. The reluctance of some parents, however, to accept vaccines for their children undermines herd immunity and compromises global public health. Research Aim: This thesis investigated the prevalence and predictors of vaccine hesitancy in caregivers of under-five children and the effect on their vaccination practices and immunisation uptake in Ondo State, Nigeria. Methodology: Data were collected from 450 caregivers using two validated vaccine hesitancy data tools and three focus group discussions with 23 participants in a sequential explanatory mixed methods study. Data analyses included descriptive, regression, and mediation analyses with bootstrapping using process macro and thematic analysis, with the findings integrated into a joint display. Findings: Results indicated that prevalence of vaccine hesitancy (28.2%) was driven by five narrative themes: Perceived risk of adverse effects of vaccines; cultural beliefs, traditional practices, and spirituality; social networks and interactions with health workers; unfavourable attitude and lack of vaccination knowledge; and phobia, with complementary coherence to quantitative findings. Employment status (OR=1.87, p=.005), age of index child (OR=2.05, p=.034) and knowledge (OR=1.87, p=.005) significantly predicted vaccine hesitancy. Furthermore, caregivers' attitudes partially mediate the effect of vaccine hesitancy on vaccination outcomes, with the mechanism of action explained using belief-behaviour inference theory. Boosting of childhood vaccine uptake was dependent on caregivers’ confidence in the importance and effectiveness of vaccines to make their child healthy. Conclusion: This research identified a benefit–driven acceptance behaviour among caregivers and confirmed that vaccine hesitancy negatively impacts vaccine uptake with the relationship mediated by attitudinal and contextual factors. The findings provide valuable insights for enhancing vaccination uptake in Ondo State, Nigeria, through multi-sectoral policy development and service improvement.