The epidemiology of varicella-zoster virus infections.

Historically, varicella has been a disease predominantly affecting preschool and school-aged children in the United States. The live attenuated varicella vaccine was licensed in this country in 1995 and has been recommended for routine use in immunization of children 12 to 18 months of age. As an increasing proportion of the children in the United States are protected from varicella by vaccination, changes in the current epidemiology of the disease are anticipated. This article reviews the current epidemiology of VZV infection and outlines issues related to possible changes in varicella epidemiology that may follow widespread use of the live varicella (Oka) vaccine.