Pneumococcal vaccination rates in children with sickle cell disease.

Context: Sickle cell disease (SCD) confers an increased risk of invasive pneumococcal disease, especially among young children. Pneumococcal vaccination decreases this risk, but the completion rate of age-appropriate vaccinations is not well defined in SCD.
Objective: The goal of this study was to assess whether pneumococcal vaccines are administered to high-risk children with SCD according to recommended vaccine schedules.
Design: A case-control design was used to conduct this study.
Setting: Administrative data were obtained on Michigan Medicaid or Children's Special Health Care Services programs enrollees. In addition, Michigan Newborn Screening and Michigan Care Improvement Registry records were used to confirm diagnosis and vaccine administration.
Participants: This study compared pneumococcal vaccination rates in a cohort of 179 children with SCD with 537 age-matched non-SCD controls (1:3) enrolled in the Michigan Medicaid Program between 2001 and 2008. Study subjects were born in the state of Michigan between 2001 and 2005.
Main Outcome Measure: The main outcome measure was the proportion of children defined as up to date for pneumococcal vaccines at defined milestone ages.
Results: Children with SCD had significantly higher vaccination rates than controls, yet these values were much lower than state and national immunization survey rates.
Conclusion: Barriers to completing age-appropriate recommended pneumococcal immunizations should be identified and addressed to further reduce invasive pneumococcal disease in this high-risk patient population.