Can someone who has been vaccinated for varicella later develop herpes zoster from the vaccine virus?
Yes. The VAERS rate of herpes zoster after varicella vaccination was 2.6/100,000 vaccine doses distributed (CDC, unpublished data, 1998). The incidence of herpes zoster after natural varicella infection among healthy children aged less than 20 years is 68/100,000 person years and, for all ages, 215/100,000 person years. However, these rates should be compared cautiously because the latter rates are based on populations monitored for longer time periods than were the vaccinees. For PCR-confirmed herpes zoster cases, the range of onset was 25-722 days after vaccination (Merck and Company, Inc., unpublished data, 1998). Cases of herpes zoster have been confirmed by PCR to be caused by both vaccine virus and wild-type virus, suggesting that some herpes zoster cases in vaccinees might result from antecedent natural varicella infection (Merck and Company, Inc., unpublished data, 1998). For more information, visit the following site: http://www.cdc.gov/epo/mmwr/preview/mmwrhtml/rr4806a1.
