Measles Transmission in a Fully Vaccinated Closed Cohort: Data From a Nosocomial Clustered Cases in a Teenage Psychiatric Unit.

We described nosocomially clustered cases of measles secondary to a nonvaccinated index case occurring in a teenage psychiatric unit despite optimum vaccine coverage. Surveillance of this fully vaccinated closed cohort showed a 7% attack rate. Vaccination limited the risk of complicated measles and the onset of a large outbreak.