Background: In response to an outbreak of measles, in February 2008, the Arizona Department of Health Services (ADHS) recommended an accelerated measles-mumps-rubella (MMR) vaccination schedule. Under this program the first dose of MMR is administered between 6-12 months of age and two subsequent doses are given at 1 and 4-6 years of age. ADHS selected a cohort of children who were eligible to get an accelerated dose during the outbreak and evaluated the outcome.
Objectives: To determine if receipt of accelerated MMR vaccine impacted completion of later MMR doses and other childhood vaccination schedules.
Methods: Immunization data from the selected cohort of children were extracted from the Arizona State Immunization Information System and analyzed retrospectively. Children with a recorded MMR dose before 1 year of age were assigned to the accelerated vaccination group. All other children comprised the standard group. For each group we calculated the timeliness and percent completion for the MMR (two doses) and other age appropriate recommended vaccinations (4:3:1:3:3:1).
Results: Vaccination records for 11,768 children were included in this study. The accelerated group contained 4,310 (36.6%) children. Children in the accelerated group were much more likely to have received a valid dose of MMR after age 1 (82.8% vs. 68.1%). Additionally, children in this group were 1.7 times more likely to complete the 4:3:1:3:3:1 series. The accelerated group required 6.39 office visits to complete the 4:3:1:3:3:1 series compared with 5.89 for the standard group.
Conclusions: An accelerated MMR vaccine was well accepted by providers and many providers were able to incorporate the accelerated dose into routine visits. Furthermore, children with an accelerated dose were more likely to complete their vaccine series on time. An accelerated program could be utilized as an outbreak control measure without having a negative impact on the receipt of other vaccines.