Introduction

Influenza is a major cause of morbidity and mortality among adults. The most effective strategy for preventing influenza is annual vaccination. However, vaccination coverage has been suboptimal among adult populations. The purpose of this study is to assess trends in influenza vaccination among adult populations.

Methods

Data from the 2010–2016 National Health Interview Survey were analyzed in 2018 to estimate vaccination coverage during the 2010–2011 through 2015–2016 seasons. Trends of vaccination in recent years were assessed. Vaccination coverage by race/ethnicity within each group was examined. Multivariable logistic regression and predictive marginal models were conducted to identify factors associated with vaccination, and interactions between race/ethnicity and other demographic and access-to-care characteristics were assessed.

Results

Vaccination coverage among adults aged ≥18 years increased from 38.3% in the 2010–2011 season to 43.4% in the 2015–2016 season, with an average increase of 1.3 percentage points annually. From the 2010–2011 through 2015–2016 seasons, coverage was stable for adults aged ≥65 years and changed by −0.1 to 9.9 percentage points for all other examined subgroups. Coverage in 2015–2016 was 70.4% for adults aged ≥65 years, 46.4% for those aged 50–64 years, and 32.3% for those aged 18–49 years; 47.9% for people aged 18–64 years with high-risk conditions; 64.8% for healthcare personnel; and 50.3% for pregnant women. Among adults aged ≥18 years for the 2015–2016 season, coverage was significantly lower among non-Hispanic blacks and Hispanics compared with non-Hispanic whites.

Conclusions

Overall, influenza vaccination coverage among adults aged ≥18 years increased during 2010–2016, but it remained below the national target of 70%. Vaccination coverage varied by age, risk status, race/ethnicity, healthcare personnel, and pregnancy status. Targeted efforts are needed to improve coverage and reduce disparities.