Herpes Zoster Risk Reduction through Exposure to Chickenpox Patients: A Systematic Multidisciplinary Review

PLoS One. 2013 Jun 21;8(6):e66485. doi: 10.1371/journal.pone.0066485. Print 2013.


Varicella-zoster virus (VZV) causes chickenpox and may subsequently reactivate to cause herpes zoster later in life. The exogenous boosting hypothesis states that re-exposure to circulating VZV can inhibit VZV reactivation and consequently also herpes zoster in VZV-immune individuals. Using this hypothesis, mathematical models predicted widespread chickenpox vaccination to increase herpes zoster incidence over more than 30 years. Some countries have postponed universal chickenpox vaccination, at least partially based on this prediction. After a systematic search and selection procedure, we analyzed different types of exogenous boosting studies. We graded 13 observational studies on herpes zoster incidence after widespread chickenpox vaccination, 4 longitudinal studies on VZV immunity after re-exposure, 9 epidemiological risk factor studies, 7 mathematical modeling studies as well as 7 other studies. We conclude that exogenous boosting exists, although not for all persons, nor in all situations. Its magnitude is yet to be determined adequately in any study field.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chickenpox* / immunology
  • Chickenpox* / therapy
  • Female
  • Herpes Zoster* / immunology
  • Herpes Zoster* / prevention & control
  • Herpesvirus 3, Human / immunology*
  • Humans
  • Male
  • Models, Immunological*
  • Observational Studies as Topic
  • Risk Factors

Grant support

BO thanks the Research Foundation Flanders (FWO) for the financial support he has received. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.