Influenza vaccination coverage of children aged 6 to 23 months: the 2002-2003 and 2003-2004 influenza seasons.

Background: Beginning in 2002 the Advisory Committee on Immunization Practices encouraged, when feasible, annual influenza vaccination of all children aged 6 to 23 months and household contacts and out-of-home caregivers of children < 2 years of age.

Objective: We sought to report influenza vaccination coverage for the 2002-2003 and 2003-2004 influenza seasons among children aged 6 to 23 months according to demographic and immunization-provider characteristics.

Methods: Data from the 2003 and 2004 National Immunization Survey were analyzed. Two measures of childhood influenza vaccination are reported: receipt of > or = 1 influenza vaccination and full vaccination (ie, receipt of the appropriate number of doses on the basis of previous vaccination history). chi2 tests and logistic-regression analyses to test for associations between influenza vaccination status and demographic characteristics were performed.

Results: In the 2002-2003 and 2003-2004 influenza seasons only 7.4% and 17.5%, respectively, of children aged 6 to 23 months received > or = 1 influenza vaccination, whereas only 4.4% and 8.4%, respectively, were fully vaccinated. In both seasons, adjusted influenza vaccination coverage was significantly lower among children living below the poverty level; non-Hispanic black children; older children; children with less-educated mothers; children vaccinated only at public clinics; and children not residing in a metropolitan statistical area.

Conclusion: During the first 2 years of the Advisory Committee on Immunization Practices' encouragement for children aged 6 to 23 months to receive influenza vaccination, coverage was low, with significant demographic differences in receipt of vaccination. Beginning with the 2004-2005 influenza season, they replaced the encouragement with a recommendation that children aged 6 to 23 months receive annual influenza vaccination. Substantial work remains to fully and equitably implement this new recommendation and ensure vaccination with 2 doses for previously unvaccinated children.