#18 Declining Influenza Vaccination Rates in an Underserved Pediatric Primary Care Center During the COVID-19 Pandemic
Authors: Day Melissa E 
Published: June 2022

Abstract

Background
Influenza vaccine hesitancy rates are increasing in the United States, even as influenza infection accounts for significant pediatric morbidity and mortality. Disinformation and controversy surrounding COVID-related public health protections and SARS-CoV-2 vaccine roll-out may have unintended consequences that impact pediatric influenza vaccination. We sought to assess influenza vaccination rates before and during the COVID-19 pandemic in one pediatric primary care center (PPCC), which serves a predominantly Medicaid-insured, minoritized population.

Method
A cross-sectional study assessed influenza vaccination rates for children aged 6 months to 12 years (~17,000 patients) over influenza seasons (September-March): 1) 2018-19 and 2019-20 (pre-pandemic rates), and 2) 2020-21 and 2021-22 (intra-pandemic rates). Demographic characteristics and social risk questionnaires (e.g., food and housing insecurity, transportation and public benefit issues, etc.) were pulled from PPCC electronic medical record data. Total tetanus vaccinations during each influenza season were used as a comparison for general vaccination rates, as clinic visits varied due to COVID-related shutdowns. Generalized linear regression models with robust standard errors (SEs) evaluated differences in demographics, social factors, and influenza vaccination rates by influenza season by specifying an appropriate distribution and link function for each factor. In a subgroup of patients with clinic visits in 2018-19 and 2020-21, influenza vaccine rates were compared using the McNemar test. Multivariable logistic regression with robust SEs evaluated associations between influenza season, demographic characteristics, reported social risks, and influenza vaccination.

Results
The percentages of patients receiving influenza vaccinations by influenza season are depicted in Table 1. Pre-pandemic, 42% of patients with a clinic visit were vaccinated (2019-20), and this rate decreased to 30% by 2021-22 during the pandemic. Both influenza and tetanus vaccinations significantly differed across influenza seasons, with lower uptake during the COVID-19 pandemic (p &lt; 0.01, Table 1). Both mean age (5.5, 5.7, 6.0, and 6.2 years for the 2018-19, 2019-20, 2020-21, and 2021-22 influenza seasons, respectively) and positive social risk screens (13%, 22%, 25%, 27% for the 2018-19, 2019-20, 2020-21, and 2021-22 influenza seasons, respectively) significantly increased across influenza seasons (p &lt; 0.01). Of a subset of 1629 patients with clinic visits in both 2018-19 and 2021-22 seasons, 42% received the influenza vaccine in 2018-19, but only 30% have received the vaccine in 2021-22 (McNemar’s test, p &lt; 0.01). In a multivariable regression model, the 2020-21 (OR 0.88 [0.82-0.94]) and 2021-22 (OR 0.68 [0.62-0.74]) influenza seasons, age (OR 0.98 [0.97-0.99]), black race (OR 0.58 [0.54-0.62]), and self-pay (OR 0.84 [0.72-0.99]) were associated with influenza vaccine refusal (p &lt; 0.05).

Conclusion
Influenza vaccination rates within one PPCC decreased over the years of the COVID-19 pandemic and have not rebounded. New interventions to promote influenza and possibly other vaccines are needed to improve evidence-based child health measures.