Factors Associated with Parental Vaccine Hesitancy in Childhood Immunization: Insights from a Cross-Sectional Survey in Southern Italy

Introduction Parental vaccine hesitancy (VH) threatens childhood immunization and may improve vaccination coverage. This study aimed to investigate parental VH factors in childhood immunization in Southern Italy, focusing on sociodemographic factors, adverse events following immunization (AEFIs), and participants perceptions of child vulnerability and health factors. Methods A cross-sectional electronic survey was conducted between September 2024 and January 2025 among parents/ caregivers of children and adolescents in Sicily and Calabria. The survey included the Parent Attitudes about Childhood Vaccines Questionnaire (PACV-5), the Child Vulnerability Scale (CVS), and the Parent Health Locus of Control Scales (PHLoC). Multivariable logistic regression models were used to identify independent factors associated with VH reporting adjusted Odds Ratio (aOR) with corresponding 95% confidence intervals (CIs). Results In this facility-based sample, 44.5% screened positive for VH in childhood immunization. Prior vaccine refusal (aOR 3.56; 95% CI: 2.09–6.06), experiencing an AEFI after the last vaccination (aOR: 2.00; 95% CI: 1.09–3.67), including more than one AEFI (aOR: 1.88; 95% CI: 1.14–3.11), or changes in hesitancy following an AEFI (aOR 5.31; 95% CI: 2.60–10.90) were associated with higher VH. PHLoC Destiny (aOR 1.43; 95% CI: 1.21–1.69) and Divine (aOR 1.14; 95% CI: 1.01–1.30) were associated with higher VH, whereas PHLoC Professionals with lower VH (aOR 0.72; 95% CI: 0.60–0.86). Conclusion Parental VH was associated with safety concerns and the influence of imponderable PHLoC factors, while trust in healthcare professionals was linked to lower VH, underscoring the need for targeted, empowerment-based communication strategies to improve vaccination confidence.