Disparities in Influenza, Pneumococcal, COVID-19 Vaccine Coverage in High-Risk Adults Aged 19 to 64 Years in Southeastern Minnesota, 2010-2021

Abstract

Background: Despite effective vaccines against influenza, pneumococcus, and COVID-19, uptake has been suboptimal.

Research question: Although disparities in vaccination by race and ethnicity have been observed, what is the role of other sociodemographic factors in US vaccine uptake?

Study design and methods: We conducted a population-based study using the Rochester Epidemiology Project (REP), a comprehensive medical records linkage system, to assess effects of sociodemographic factors including race, ethnicity, individual-level socioeconomic status (SES) via the housing-based socioeconomic status index, education, population density (urban or nonurban), and marital status with uptake of influenza, pneumococcal, and COVID-19 vaccination in high-risk adults. Adults at high risk of invasive pneumococcal disease residing in four counties in southeastern Minnesota who were aged 19 to 64 years were identified. Vaccination data were obtained from the Minnesota Immunization Information Connection and REP from January 1, 2010, through December 31, 2021.

Results: We identified 45,755 residents. Most were White (82%), non-Hispanic (94%), married (56%), and living in an urban setting (81%), with three-quarters obtaining at least some college education (74%). Although 45.1% were up to date on pneumococcal vaccines, 60.1% had completed the primary COVID-19 series. For influenza and COVID-19, higher SES, living in an urban setting, older age, and higher education positively correlated with vaccination. Magnitude of differences in race, education, and SES widened with booster vaccines.

Interpretation: This high-risk population is undervaccinated against preventable respiratory diseases, especially influenza and pneumococcus. Although national data reported improvement of disparities in COVID-19 vaccination uptake observed early in the pandemic, our data demonstrated gaps related to race, education level, SES, and age that widened with booster vaccines. Communities with high social vulnerabilities often show increased risk of severe disease outcomes, yet demonstrate lower uptake of preventive services. This highlights the need to understand better vaccine compliance and access in rural, lower SES, less-educated, Black, Hispanic, and younger populations, each of which were associated independently with decreased vaccination.

Keywords: adult; health care disparities; respiratory tract infections; risk factors; sociodemographic factors; vaccines.