BACKGROUND:
Poverty and factors associated with it are the most persistent and powerful barriers to immunization. Despite the fact that there are federal programs, such as WIC that provide immunizations available for the underprivileged, this population still presents a higher rate of underimmunization. Existing immunization programs need to be assessed to ensure that they are sufficiently utilized before new programs are implemented.

OBJECTIVE:
To determine if increased utilization of WIC services correlates with greater up-to-date status of immunization levels.

METHOD:
A retrospective analysis was conducted using the CDC's National Immunization Survey (NIS) covering years 1995 – 2001. Poverty status was determined using national definitions, the 4:3:1:3 immunization series provider-reported UTD status was the outcome of interest and weighted percentages were computed. WIC participation rates were obtained from the 2002 Executive Summary Report of WIC Services. Weighted chi-square analyses were used to determine trends in WIC participation and UTD status by ethnic group.

RESULT:
WIC services are severely underutilized (20% - 40%) among underprivileged Hispanics, White-Americans and African-Americans. As poverty levels among Hispanics increased, both, WIC and UTD rates (range: 65% - 73%) also increased. For White-American and African-American children, as poverty levels rose, utilization of WIC services decreased. While UTD status amongst White-Americans rose (range: 68% - 77%) in the same period, UTD rates among African-Americans decreased (range: 68% - 72%).

CONCLUSION:
Utilization of WIC services among children at or below poverty level appears to be directly associated with immunization status.

LEARNING OBJECTIVES:
These findings may serve as a foundation for identifying barriers to use of WIC services by those eligible and subsequently result in implementing outreach programs that promote utilization of such federal programs.