Private-sector vaccine purchase costs and insurer payments: a disincentive for using combination vaccines?

Combination vaccines have been endorsed as a means to decrease the number of injections needed to complete the childhood immunization schedule, yet anecdotal reports suggest that private providers lose money on combination vaccines. The objective of this study was to determine whether practices purchasing combination vaccines had significantly different vaccine costs and reimbursement compared to practices that were not purchasing combination vaccines. Using cross-sectional purchase and insurer payment data collected from a targeted sample of private practices in five US states, we calculated the average total vaccine cost and reimbursement across the childhood immunization schedule. The average vaccine purchase cost across the childhood schedule was significantly higher for practices using a combined vaccine with diphtheria, tetanus, acellular pertussis vaccine, inactivated polio vaccine, and Hepatitis B vaccine (DTaP-IPV-HepB) than for practices using either separate vaccine products or a combined vaccine with Haemophilus influenzae, type b vaccine and Hepatitis B vaccine (Hib-HepB). The average insurer payment for vaccine administration across the childhood schedule was significantly lower for practices using DTaP-IPV-HepB combination vaccine than for practices using separate vaccine products. This study appears to validate anecdotal reports that vaccine purchase costs and insurer payment for combination vaccines can have a negative financial impact for practices that purchase childhood vaccines.