Up-to-Date Haemophilus influenzae Type b Vaccination Coverage During a Vaccine Shortage

Abstract

OBJECTIVES: We sought to assess Haemophilus influenzae type b (Hib) vaccination coverage in diverse areas of the United States during the 2008–2009 Hib vaccine shortage. Interim recommendations for Hib vaccination during the shortage called for deferral of the booster dose only among children not at high risk for disease; the primary series given during the first year of life continued to be recommended for all children. METHODS: Vaccination data on ∼123 000 children were collected from 8 Immunization Information System (IIS) sentinel sites. Completion of the primary Hib series (with 2 or 3 doses depending on vaccine type) by 9 months old during the vaccine shortage was compared with coverage of 2 vaccines given at similar ages (7-valent pneumococcal conjugate vaccine and diphtheria, tetanus acellular pertussis vaccine) in children born between November 1, 2007, and March 31, 2008. RESULTS: During the shortage period, Hib vaccination coverage for the primary series was 7.8 to 10.3 percentage points lower than diphtheria, tetanus acellular pertussis vaccine and 7-valent pneumococcal conjugate vaccine coverage for children by the age of 9 months in 7 of 8 sentinel sites. CONCLUSIONS: A significant decrease in Hib vaccination coverage for the primary series was observed and was consistent across several US localities. Close collaboration between the public health community and vaccine providers is essential during vaccine shortages to ensure that interim vaccination recommendations are clear, widely disseminated, and closely followed, and that access to available vaccine supplies is maintained.