Assessing immunization interventions in the Women, Infants, and Children (WIC) program

Vaccination promotion strategies are recommended in Women, Infants, and Children (WIC) settings for eligible children at risk for under-immunization due to their low-income status.

To determine coverage levels of WIC and non-WIC participants and assess effectiveness of immunization intervention strategies.

The 2007-2011 National Immunization Surveys were used to analyze vaccination histories and WIC participation among children aged 24-35 months. Grantee data on immunization activities in WIC settings were collected from the 2010 WIC Linkage Annual Report Survey. Coverage by WIC eligibility and participation status and grantee-specific coverage by intervention strategy were determined at 24 months for select antigens. Data were collected 2007-2011 and analyzed in 2013.

Of 13,183 age-eligible children, 5,699 (61%, weighted) had participated in WIC, of which 3,404 (62%, weighted) were current participants. In 2011, differences in four or more doses of the diphtheria, tetanus toxoid, and acellular pertussis (DTaP) vaccine by WIC participation status were observed: 86% (ineligible); 84% (current); 77% (previous); and 69% (never-eligible). Children in WIC exposed to an immunization intervention strategy had higher coverage levels than WIC-eligible children who never participated, with differences as great as 15% (DTaP).

Children who never participated in WIC, but were eligible, had the lowest vaccination coverage. Current WIC participants had vaccination coverage comparable to more affluent children, and higher coverage than previous WIC participants.