Importance of Catch-up Vaccination: Experience From a Varicella Outbreak, Maine, 2002–2003

This outbreak was attributable primarily to failure to vaccinate, especially among children in grades 1 through 3. Catch-up vaccination of susceptible older children and adolescents is especially important to prevent accumulation of susceptibility in these groups, in which the natural disease is more severe. School entry requirements will contribute to a more rapid implementation of the existing recommendations for vaccination.