Universal varicella vaccination increased the incidence of herpes zoster in the child-rearing generation as its short-term effect

Varicella zoster virus (VZV) infection causes varicella and results in latent infection of the sensory ganglia, and its reactivation causes herpes zoster (HZ). Dr. Takahashi developed the varicella vaccine [1], and introduction of universal varicella vaccination has eliminated varicella epidemics [2]. HZ increases at the age of 50 years or older, and the incidence is increasing in the epidemiologic studies [3–8]. Exposure to varicella boosts the immunity to VZV and has been reported to reduce the incidence of HZ in many epidemiologic studies [8–11].