Compliance with vaccination recommendations for US children

Background: Official recommendations for the routine vaccination of U.S. children, made by the Advisory Committee on Immunization Practices (ACIP), specify the vaccines for administration, the number of doses that should be given, the age ranges for administration, the minimum ages at which doses are considered valid, the minimum intervals between doses within a series, and several additional vaccine-specific adjustments and exceptions. Federally reported estimates of vaccination coverage measure only compliance with the required number of doses; other recommendations are not routinely evaluated. Methods: Analysis of vaccination histories for 17,563 U.S. children aged 19-35 months from the 2005 National Immunization Survey. Main Outcome Measures: Compliance with, and incremental impact of, each vaccination recommendation. Results: Estimated coverage was 72% for the standard vaccination series accounting for all recommendations, 9 percentage points lower than coverage based solely on counting doses. Overall, 19% of children were missing one or more doses, while 8% had received an invalid dose, and 9% were affected by other recommendations. The proportion of noncompliance due to missed doses versus other recommendations varied by state and by antigen. Conclusions: Approximately 28% of children were not in compliance with the official vaccination recommendations. Missed doses accounted for approximately two thirds of noncompliance, with the remainder due to mis-timed doses and other requirements. Measuring compliance with all ACIP recommendations provides a valuable tool to assess and improve the quality of healthcare delivery and ensure that children and communities are optimally protected from vaccine-preventable diseases.