Universal Varicella Vaccination Programmes in European Countries and their Effect: A Systematic Review

Varicella zoster virus causes primary varicella and herpes zoster (HZ). Decisions to include Universal Varicella Vaccination (UVV) in routine childhood immunisation schedules in European countries have varied significantly. A systematic review was conducted to assess UVV implementation in European countries and its effects. Systematic Review A search identified relevant literature published from 2010-2025, in all languages. Three databases (PubMed, CINAHL, and EMBASE) were searched in March 2025 for empiric studies reporting real-world data on varicella and HZ epidemiology in European countries which have adopted UVV. Modelling studies and non-primary studies were excluded. The Mixed Methods Appraisal Tool (MMAT) was used to assess quality of included studies. Quantitative outcomes were analysed through meta-analyses, while qualitatively expressed outcomes were synthesised narratively. The systematic review protocol was registered in PROSPERO (Ref:CRD420250650902). Forty-one of 437 identified studies met the inclusion criteria, comprising descriptive studies (34), non-randomised studies (6) and mixed methods studies (1) from 5 of 16 European countries with UVV. Vaccination regimes have varied across countries, differing in dosing schedules and use of monovalent or tetravalent vaccines. Reductions in varicella incidence (Incidence Rate Ratio 0.46, 95% CI 0.39–0.54) and hospitalisation (IRR 0.6, 95% CI 0.53–0.69) have been observed. To date, no conclusive increase in incidence among older age groups or in the burden of herpes zoster has been identified. Physician recommendation remains the strongest factor influencing uptake. Introduction of UVV in European countries has coincided with reduction in varicella incidence and hospitalisations related to varicella. Heterogeneity was high among studies, and 17/41 met all methodological criteria required by the MMAT. Surveillance of varicella and HZ varies across Europe, challenging attempts to compare strategies. Physicians in countries adopting UVV should be supported to encourage uptake and ensure adequate coverage.