BACKGROUND:
The most recent disruption in the supply of pneumoccocal conjugate vaccine (PCV) began in February 2004 and ended in September 2004. In order to extend available supplies to the highest risk children, it was recommended by CDC that providers delay administration of the third and fourth doses of vaccine to healthy children. We used registry data from the Michigan Child Immunization Registry (MCIR) to evaluate changes in PCV coverage rates in Michigan.

OBJECTIVE:
To evaluate the usefulness of registry data to monitor provider compliance with CDC recommendations for conservation of PCV during the 2004 shortage.

METHOD:
Data for individual immunization records were obtained for a cohort of children enrolled in MCIR as of February 29, 2004. Vaccination data were collected through July, 2004. The proportion of children who received DTaP3 and PCV3 at seven months of age was calculated for each birth month. The proportion who received MMR1 and PCV4 at sixteen months of age was also calculated. Coverage rates were compared between public and private provider type as well as by practice specialty.

RESULT:
As of July 2004, 597,000 (94%) of 600,826 children in the registry had at least one shot record and are included in the analysis. Coverage for DTaP3 and MMR1 remained steady while PCV coverage declined at each time point when recommendations were announced. The sharpest decline was observed for PCV3 at seven months of age when coverage dropped from 28% to 10%. PCV coverage trends were similar for public and private providers as well as for pediatricians and family practitioners.

CONCLUSION:
Michigan immunization providers appear to be complying with CDC recommendations for PCV administration. Registry data can be useful in evaluating vaccination coverage trends during a shortage.

LEARNING OBJECTIVES:
To describe how registry data can be used to evaluate compliance with recommendations to conserve vaccines.