Changes in age related seroprevalence of antibody to varicella zoster virus: impact on vaccine strategy

Aim: To study changes in the seroprevalence of varicella zoster virus (VZV) antibody over the past 25 years with a view to determining the target age group for any future vaccination strategy. Methods: Stored sera collected from different age groups over a period of 25 years were tested by a commercial VZV IgG enzyme immunoassay at a four year time interval. Data were analysed by logistic regression to investigate the evidence for changes in incidence and hence seroprevalence over that period. Results: There was a significant rise in VZV antibody prevalence in the 1-4 year age group during the study period. Conclusions: A universal childhood VZV vaccination strategy will need to take account of the increase in incidence of VZV infection in children under the age of 4 years; hence, the suggested target age would be between 12 and 18 months-soon after the disappearance of maternal antibody.