Household exposure to varicella appears to reduce herpes zoster (HZ) risk by ~30% within 2 years and by 27% in 10-20 years postexposure.
Why this matters
- Exogenous varicella boosting in adults provides incomplete immunity against HZ.
- Consider Zostavax (zoster vaccine live) in adult patients aged ≥50 years.
- 9604 adults with HZ.
- Median age, first varicella exposure: 41.1 (interquartile range, 33.1-51.3) years.
- 1.2% (118) severely immunosuppressed at exposure.
- Adjusted HZ incidence ratio (IR),
- IR, 0.67 (95% CI, 0.62-0.73).
- IR, 0.73 (95% CI, 0.62-0.87).
- 10-20 years: IR, 0.59 men vs 0.82 women (P<.001>
- Self-controlled case series analysis of relative risk of HZ over time following exposure to household contact with varicella based on UK electronic health records (EHRs).
- Funding: UK Medical Research Council; others.
- Varicella underestimated in UK EHRs.
- Household exposure misclassifications; bias toward the null.
- Uncaptured occupational exposure; bias away from the null.
- Underpowered to detect boosting effect in immunocompromised.