Universal Varicella Vaccination and its Effects in European Countries: A Systematic Review

Abstract Background 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. Methods 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. The Mixed Methods Appraisal Tool was used to assess quality of included studies. Meta-analyses of quantitative outcomes and narrative syntheses of other outcomes were performed. Results 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) are reported. To date, no conclusive increased incidence in older age groups or in HZ burden has been reported. Physician recommendation is the strongest identified factor influencing uptake. Conclusions Introduction of UVV in European countries has coincided with reduction in varicella incidence and hospitalisations related to varicella. 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. Key messages • Universal Varicella Vaccination introduction has coincided with a reduction in varicella burden in European countries without conclusive evidence of increased cases in older ages or in HZ burden. • Physician recommendation is the strongest factor influencing acceptance of varicella vaccination in European countries with universal varicella vaccination.