The zoster vaccine has been shown to substantially reduce the burden of illness due to herpes zoster among adults over 60 years of age.
Herpes zoster (shingles) occurs when there is reactivation of latent varicella virus
present in dorsal sensory and cranial nerve ganglia. It manifests as pain and vesicular lesions in a classically dermatomal distribution (Figure). Postherpetic neuralgia, which is a difficult condition to manage, can subsequently occur and lead to significant morbidity, particularly in the elderly.
The incidence of herpes zoster increases with age, from 1.9 per 1000 person-years in the 25- to 34-year age group to 11.8 per 1000 person-years in those over 65 years of age. Declining cell-mediated immunity with increasing age is believed to allow for reactivation of the virus.