Featured in NEJM Journal Watch: Protection Wanes After the First Dose of DTaP

By the NEJM Journal Watch Editors

Pertussis protection is good during the first year but wanes without subsequent booster doses, according to a study in Pediatrics.

Among 4584 confirmed cases of pertussis and matched healthy controls between 2005 and 2009, vaccine efficacy against reported cases steadily declined from 80% in the first year to 50% by age 4 years in children who received vaccines at ages 2, 4, and 6 months. Efficacy against hospitalization after one dose of DTaP was 55% and increased to 80% after the second dose but subsequently declined during the second and third years without booster administration.