Parental vaccine refusal, non-vaccinated children, and outbreaks of Vaccine-Preventable Diseases (VPDs) in Europe: a systematic review of aetiology and risk

This systematic review provides compelling evidence of an association between intentionally unvaccinated children-those unvaccinated due to parental refusal-and outbreaks of vaccine-preventable diseases (VPDs). The findings strongly suggest that this group contributes significantly to VPD outbreaks within the European region. To deepen our understanding, further research is needed to compare the role of intentionally unvaccinated children with that of other unvaccinated groups (e.g., those unvaccinated due to medical contraindications, immunosuppression, or limited access to healthcare) in the emergence and spread of VPDs.