Objective: To assess the impact of using the combined measles, mumps, rubella, and varicella vaccine (MMRV) instead of the measles, mumps, and rubella vaccine and the varicella vaccine separately (MMR+V) on uptake of vaccines recommended by the Advisory Committee for Immunization Practices (ACIP) in young children.
Study design: Retrospective cohort study.
Methods: Electronic immunization records of children 12 to 15 months of age who received either MMR+V (n = 29,716) or MMRV (n = 29,711) between November 2003 and June 2007 while enrolled in Kaiser Permanente Southern California were evaluated. Proportions of children who received either MMRV or MMR+V and other ACIP-recommended vaccines either simultaneously or during recommended age intervals were compared.
Results: Concomitant administration of DTaP (76.3 vs 75.6%), PCV7 (89.1 vs 78.6%), Hib (92.3 vs 91.3%), and hepatitis A vaccine (HAV) (44.2 vs 0.1%) and on-time administration of PCV7 (91.7 vs 78.7%), Hib (93.9 vs 93.2%), and HAV (86.8 vs 24.3%) were greater with MMRV than with MMR+V. On-time administration of DTaP (91.4 vs 90.5%) and IPV (91.3 vs 90.0%) was greater with MMR+V than with MMRV.
Conclusions: Concomitant and on-time administration of most ACIP-recommended vaccines was greater with MMRV than with MMR+V despite the addition of HAV to the recommended schedule after introduction of MMRV. However, the modest compliance increases suggest that focusing on other barriers to compliance may be important to increasing adherence to future vaccination recommendations.