PRO AND CONS OF UNIVERSAL VARICELLA VACCINATION IN EUROPE:
THE EUROVAR INITIATIVE

N. Stouvenakers, C. Sadzot-Delvaux & B. Rentier
Department of Virology, University of Liège, Belgium.

Varicella vaccination is considered very differently in Europe and in the USA where universal vaccination has been recommended since 1995. In Europe, varicella vaccine is restricted to individuals at risk (immunocompromised). The American experience cannot be considered as a transposable model due to many cultural differences and healthcare delivery systems throughout Europe, which are largely driven by national policies. Other barriers to universal varicella vaccination include the perception that varicella is a benign childhood illness and that there are other vaccination priorities. Severe cases and complications due to varicella are underestimated because of a lack of adequate epidemiological surveys, making the extent and severity of varicella cases difficult to assess.

As part of its ongoing efforts to forge international, scientific exchange, the VZV Research Foundation (VZVRF) has formed the European Working Group on Varicella Vaccination: (EuroVar), whose primary objective is to gather epidemiological data on chickenpox in Europe and to explore the need for and the feasibility of universal varicella vaccination in Europe. It is composed of 20 scientists representing the USA and 12 European countries.

Today EuroVar has reached a consensus on two objectives: (1) varicella should be prevented; and (2) varicella vaccination should be offered to all healthy children between 12 and 18 months of age. However such recommendations can only be carried out if there are guaranties that a very large vaccine coverage can be achieved. The waning of specific immunity should be carefully monitored over the years in a representative population sample in order to enforce boosting if necessary. The existence of breakthrough cases, the effect on zoster epidemiology and the cost of vaccination are additional areas of concern that should be kept under scrutiny.

The current development of a tetravalent measles-mumps-rubella-varicella (MMRV) vaccine will advance the implementation of universal varicella vaccination. However, an extensive effort must be made to improve our knowledge of varicella epidemiology in Europe.

EuroVar is supported by a grant from the VZV Research Foundation.

Corresponding Author: N. Stouvenakers, Ph.D., Scientific Secretary of EuroVar, Department of Virology - Prof. B. Rentier, University of Liège, Domaine Universitaire du Sart-Tilman, B-4000 Liege, Belgium