Varicella susceptibility and incidence of herpes zoster among children and adolescents in a community under active surveillance.

Licensure of varicella vaccine by the US Food and Drug Administration in March 1995 has given rise to concerns that include a potential shift in varicella incidence to susceptible adults and increase in herpes zoster (HZ) incidence. Baseline values prior to widespread vaccination were obtained through distribution of an adolescent survey to all 13 public middle (seventh and eighth grade) schools in the Antelope Valley, CA health district. Based on 4216 respondents aged 10-14 years, varicella susceptibility is 7.7% (95% CI, 6.9-8.5%) and true cumulative (1987-2000) HZ incidence rate is 133 per 100,000 person-years (95% CI, 95-182 per 100,000 person-years).