MANAGING VARICELLA – AN EXAMPLE FOR EUROPE

P. Wutzler

Institute for Antiviral Chemotherapy, University of Jena, Jena, Germany

INTRODUCTION: Varicella zoster virus (VZV) infection remains a persistent cause of morbidity and mortality in healthy individuals. Although usually a mild disease in otherwise healthy children, varicella can be a complicated and even life-threatening disease in adolescents, young adults, pregnant women and immunocompromised patients.

OBJECTIVES: To determine the status of immunity to VZV in the German population, and to assess the clinical and economic benefits of universal varicella vaccination of children.

METHODS: For a seroepidemiological survey, 4,602 sera from individuals aged 1–80 years were tested for VZV IgG by means of an indirect enzyme immunoassay and the fluorescent antibody to membrane antigen (FAMA) assay. Clinical and economic outcomes of universal varicella vaccination versus no vaccination in infants were compared using a decision–analytical model, which predicts the clinical effects, direct and indirect costs, and cost-effectiveness of mass vaccination programmes. Epidemiological and resource utilisation data were derived mainly from an extensive survey conducted across Germany.

RESULTS: The prevalence of VZV antibodies rose steeply after the age of 4–5 years and reached high levels of  95% among subjects aged 10–11 years or older. Assuming a vaccination coverage of 80%, the model predicts, for the timeframe of 30 years, that universal child vaccination could prevent 17.7 million varicella infections and around 171,000 major complications. The cost–benefit ratio would be approximately 4.4.

CONCLUSIONS: Although there is no evidence of a shift in varicella susceptibility from infants to older age groups in Germany, universal varicella vaccination could provide significant clinical and economic benefits for the German society. A combined measles, mumps, rubella and varicella (MMRV) vaccine, which would provide the required protection against VZV infection without the costs or inconvenience associated with adding an additional vaccine to existing vaccination schedules, would represent the most convenient and cost-effective means of achieving this goal.