Disparities in Adult Influenza Vaccination in the United States: Analysis of 2023 BRFSS Data

Abstract

Despite longstanding recommendations for universal adult influenza vaccination, coverage remains suboptimal in the United States (U.S.). The objective of this study is to examine current influenza vaccination coverage and identify demographic, socioeconomic, and geographic disparities in vaccination among U.S. adults. Cross-sectional analysis of 2023 Behavioral Risk Factor Surveillance System data from 402,005 adults across 52 states/territories. Survey-weighted logistic regression models assessed independent predictors of self-reported influenza vaccination in the past twelve months, including demographics, socioeconomic factors, healthcare access, and health status. Overall vaccination coverage was 42.2% (95% CI 42.0–42.4%), well below the Healthy People 2030 target of 70%. Coverage increased markedly with age, from 29.2% among 18–24 year-olds to 66.9% among those ≥ 80 years of age. Women had higher coverage than men (45.4% vs. 38.7%, p < 0.001). Strong socioeconomic gradients emerged: coverage among college graduates (54.3%) exceeded that of those with less than a high school education (32.6%) and those earning ≥ $200,000 (53.5%) exceeded those earning < $15,000 (34.4%). Insurance status showed the largest disparity—45.1% of insured versus 16.2% of uninsured adults were vaccinated. Geographic variation was substantial, ranging from 19.1% in the Virgin Islands to 56.6% in Massachusetts. In multivariable analysis, the strongest predictors were advanced age (≥ 80 years: adjusted OR = 3.51, 95% CI 3.18–3.87), insurance coverage (adjusted OR = 1.74, 95% CI 1.57–1.93), and recent healthcare engagement (checkup within past year; adjusted OR = 1.62, 95% CI 1.53–1.73). Influenza vaccination coverage remains far below national targets, with pronounced disparities across age, socioeconomic status, insurance coverage, and geography. These findings suggest that efforts to advance equity may benefit from addressing structural barriers, such as expanding insurance coverage, workplace vaccination programs, and targeted outreach to underserved populations; because the data are observational, these represent potential implications rather than conclusions about causal effects. Influenza (flu) is a highly contagious respiratory illness caused by the influenza virus. Annual influenza vaccination has been shown to reduce the incidence of influenza as well as its related complications such as hospitalization, respiratory failure, and even death. Despite longstanding recommendations for universal adult influenza vaccination, the Centers for Disease Control and Prevention (CDC) estimates that only about half of U.S. adults receive the vaccine on an annual basis. The goal of this project was to evaluate current influenza vaccination coverage and identify factors that may influence whether adults choose to be vaccinated. We performed an analysis of data from the CDC's Behavioral Risk Factor Surveillance System (BRFSS), the nation's largest continuously conducted health survey system. The data included telephonic survey responses from 402,005 adults across 52 states/territories. The survey asks respondents to provide their age, sex, race/ethnicity, education level, household income, health insurance status, self-rated health status, and influenza vaccination status. Main results of the analysis include: overall only 42% of respondents reported receiving the influenza vaccine. Coverage increased markedly with age, from 29% among 18–24 year-olds to 67% among those 80 years of age or older. Other strong predictors of receiving influenza vaccination included having a higher education level, higher household income, and health insurance. These data point to the need for public health initiatives that expand access of the influenza vaccine to young adults, those with limited education and/or income, as well as uninsured adults.