Worth a Shot: Experience and Lessons From an Unsuccessful Pediatric Immunization Quality Improvement Effort in a Large Health System During the COVID-19 Pandemic.

Introduction During the coronavirus disease of 2019 (COVID-19) pandemic, routine childhood immunization rates dropped dramatically across the world, and the Military Health System (MHS) was no exception. In the MHS, which is a large, universally covered, low-to-no-cost health system, the immunization rates with the measles, mumps, and rubella (MMR) vaccine remain below the rate necessary to prevent community transmission of measles. We aimed to improve childhood immunization rates in the MHS with an expansive quality improvement project. Materials and Methods Measles, mumps, and rubella immunization rates served as proxy outcome measures for routine immunization rates tracked by the Center for Disease Control multi-immunization combination measures. The tracked measure was the percentage of 16- to 18-month olds and 6-year olds who had received MMR #1 and MMR #2, respectively. Various countermeasures were implemented throughout the study period, and standard quality improvement analyses informed the effect of countermeasures. Results By January 2023, the percentage of 16- to 18-month olds and 6-year olds who had received MMR #1 and MMR #2 was 85% and 91%, respectively, with no positive shift in immunization rates despite various countermeasures introduced during the study period. For reference, the MMR immunization rates of commercial health maintenance organization and commercial preferred provider organization for 24-month-old populations were 92% and 90.3%, respectively. On chart review, the most common cause for under-immunization (55%) was vaccine abandonment. MMR #1 rates rose to 92% in 24-month olds. Conclusions Measles, mumps, and rubella immunization rates within the MHS remained below commercial health system rates and below public health standards required for herd immunity despite various countermeasures throughout the COVID-19 pandemic. Immunization rates increased with age, suggesting that children within the MHS eventually catch up despite potential barriers. [ABSTRACT FROM AUTHOR]