Can varicella immunization change the course of herpes zoster while herpes zoster vaccine is underway?

Abstract

There is a theoretical risk, arising from mathematic models, that a universal varicella vaccination program might lead to an increase in herpes zoster (HZ) incidence. We have searched the Medline database to review HZ epidemiologic data in countries that have had varicella vaccination programs in place for many years, and in countries with either short-term routine varicella vaccination programs or no varicella vaccination programs, to examine whether these programs influence HZ incidence. We have also taken into account factors that may affect HZ epidemiology over time, such as use of the new zoster vaccine. Increases in HZ incidence rates have been observed in many countries that have had no varicella vaccination program in place for the last 20 years. The hypothesis that the decreased exposure of adults to the varicella zoster virus owing to routine varicella vaccination programs might increase HZ incidence has not been consistently proven by current data. The combined routine implementation of varicel...