Results of the 2007 Immunization Status Survey of 24-Month-Old Children in Tennessee

Background:
Since 1980, the Tennessee Immunization Program (TIP) has conducted an annual survey of the immunization status of 24-month-old children in the state. Vaccine coverage is reported for individual vaccines and for the combined "4:3:1:3:3:1" series. Coverage is measured at the state level and within each of the state's 13 health department regions.

Objectives:
The primary objective is to measure progress toward the goal of at least 90 percent on-time coverage for each routinely recommended vaccine. A secondary objective is to identify regional and racial disparities.

Methods:
A random sample of 121 birth certificates of children born in the first quarter of 2005 was pulled from the state vital records database for each of the 13 health department regions (n=1573). Oversampling of children of black race was done if the number of records of black children did not match the expected number based upon census data for the region; oversampled records were used only in statewide analysis of racial disparities. Dates of vaccination were documented from the state immunization registry, parents or health care providers.

Results:
Statewide, 82.4 percent of 24-month-old children had completed the 4:3:1:3:3:1 series. Regionally, coverage rates fell as one moved from east to west across the state. DTaP is the only vaccine required for child care attendance that did not achieve the 90 percent coverage goal. Statistically significant racial disparities were identified for DTaP, PCV and influenza vaccines.

Conclusions:
This survey describes regional and racial disparities in on-time immunization of 24-month-old children in Tennessee. The racial disparity in the 4:3:1:3:3:1 series is explained by the DTaP component. Racial disparities are widest for vaccines not required for school or child care attendance. Future regulatory changes will require PCV for child care in Tennessee.