Pediatric influenza vaccination rates lower than previous estimates in the United States.

Background: Annually, pediatric influenza vaccination coverage estimates are ascertained from health surveys, such as the National Immunization Survey (NIS-Flu). From 2010 to 2017, vaccination coverage among children ranged from 51 to 59 %. Recognizing the limitations of national health survey data, we sought to describe temporal trends in pediatric influenza vaccination coverage, and demographic differences among a commercially insured large national cohort from 07/01/2010 to 06/30/2017.

Methods: Influenza vaccination coverage was assessed among children (<18 years) with continuous enrollment in the de-identified Optum Clinformatics® Data Mart database, and from NIS-Flu. Time trends in vaccination coverage were assessed using Joinpoint regression, overall and stratified by age group, sex, and geographic region.

Results: The average annual pediatric influenza vaccination coverage was 33.4 % in our study population versus 56.5 % reported from NIS-Flu during the same period (p-value < 0.0001). Vaccination coverage was highest in children 6 months-4-years old at 52.6 % (versus 68.8 % NIS-Flu, p-value < 0.0001), and lowest in the 13-17-year-old age group at 20.1 % (versus 42.8 % NIS-Flu, p-value < 0.0001). Vaccination coverage over time remained stable in our study population (average annual percent change 1.8 %, 95 % confidence interval [CI] -2.3 % to 6.0 %) versus significantly increasing by 2.8 % in NIS-Flu (95 % CI 0.3 % to 5.3 %).

Conclusions: Vaccination coverage in our commercially insured pediatric population was 51.4% lower than estimates from NIS-Flu during the same period, suggesting the need for more accurate vaccination coverage surveillance, which will also be critical in future COVID-19 vaccination efforts. Effective interventions are needed to increase pediatric influenza vaccination rates to the Healthy People 2020 target of 70%.