BACKGROUND:
Pediarix, a combination product containing DTaP, hepatitis B, and inactivated polio viruses, was licensed on December 13, 2002 and added to the Vaccines for Children Program February 26, 2003. Little has been reported describing the uptake of the vaccine by providers.

OBJECTIVE:
To describe the uptake of Pediarix vaccine by providers in Oklahoma and Michigan, using immunization registries in each state.

METHOD:
Data were extracted from two immunization registries: the Oklahoma State Immunization Information System (OSIIS) and the Michigan Childhood Immunization Registry (MCIR). Shot records for all children born between November 1996 and October 2003 were extracted from OSIIS on 12/3/2003 and from MCIR on 12/5/2003. Data from MCIR were limited to records for children residing in three counties designated as sentinel sites. Shot records were stripped of personal identifiers and included child information on date of birth, shot information on vaccine code, date of vaccination, and provider information on type of practice.

RESULT:
In Oklahoma, doses of Pediarix were administered beginning in January 2003. By October 2003, 287 of 833 (34%) provider sites that had given at least one vaccine to children in the study cohort, had administered Pediarix. By type of provider site, 93/191 (49%) of county health department sites, 21/46(46%) IHS sites, and 139/473 (29%) private provider sites had used Pediarix. Pediarix accounted for 44 % of all DTaP containing vaccine doses administered in October 2003 to the study cohort.
In Michigan, uptake of Pediarix also began in January 2003, but progressed more slowly. By October 2003, 6 of 171 (4%) public provider sites and 62 of 915 (7%) private provider sites had administered Pediarix. Pediarix accounted for 8% of all DTaP containing vaccine administered in October 2003.

CONCLUSION:
In the two states evaluated, uptake of Pediarix differed markedly, with rapid uptake in Oklahoma and slow uptake in Michigan.

LEARNING OBJECTIVES:
Describe the uptake of Pediarix vaccine in Oklahoma and Michigan and the providers administering the vaccine using immunization registry data.