Worth a Shot: Experience and Lessons From an Unsuccessful Pediatric Immunization Quality Improvement Effort in a...

Area of Science:

• Public Health
• Immunization Science
• Healthcare Quality Improvement

Background:

• Routine childhood immunization rates, including measles, mumps, and rubella (MMR) vaccine uptake, significantly declined globally during the COVID-19 pandemic.
• The Military Health System (MHS) experienced a similar drop, with MMR immunization rates falling below the threshold required for community measles prevention.
• Despite being a universally covered, low-cost system, MHS faced challenges in maintaining adequate vaccination coverage.

Purpose of the Study:

• To implement and assess an expansive quality improvement project aimed at increasing childhood immunization rates within the MHS.
• To evaluate the effectiveness of various countermeasures in boosting MMR vaccination coverage.

Main Methods:

• Measles, mumps, and rubella (MMR) immunization rates for 16- to 18-month-olds (MMR #1) and 6-year-olds (MMR #2) were used as proxy outcome measures.
• Standard quality improvement analyses were employed to track and assess the impact of implemented countermeasures over the study period.
• Chart reviews were conducted to identify reasons for under-immunization.

Main Results:

• By January 2023, MMR #1 and MMR #2 rates reached 85% and 91%, respectively, showing no significant improvement despite interventions.
• These rates remained below those observed in commercial health maintenance organizations (92%) and preferred provider organizations (90.3%) for 24-month-olds.
• Vaccine abandonment was identified as the most common reason for under-immunization, accounting for 55% of cases. MMR #1 rates in 24-month-olds eventually reached 92%.

Conclusions:

• MMR immunization rates in the MHS did not meet public health standards for herd immunity, even after implementing multiple countermeasures during the pandemic.
• Rates were consistently lower than those in comparable commercial healthcare systems.
• An observed increase in immunization rates with age suggests that children eventually receive vaccinations, indicating potential for catch-up but highlighting persistent barriers.