Neonatal vaccine-strain varicella-zoster virus infection 22 days after maternal postpartum vaccination.

A 25-day-old infant developed varicella 22 days after her mother received varicella vaccine postpartum. Infection with vaccine-strain varicella-zoster virus was confirmed by genetic analysis. The mother had no postvaccination rash nor did other contacts have rash or recent vaccination. The potential means of transmission to the infant are explored.