Racial Disparities Shown for Influenza Hospitalizations, Vaccination Coverage

Racial and ethnic disparities persist regarding severity and vaccination coverage of influenza, according to the latest CDC Morbidity and Mortality Weekly Report.

Characterized as a contagious respiratory disease, CDC estimates indicate that influenza resulted in 9 million to 41 million illnesses, 140,000 to 710,000 hospitalizations, and 12,000 to 52,000 deaths annually during 2010-2020. Some racial and ethnic minority groups have historically shown higher rates of severe influenza compared with White individuals, noted researchers, as well as lower vaccination rates for the disease.

“Vaccination provides important protection from influenza illness and its potential complications,” they explained. “For example, during the 2019-20 season, influenza vaccination prevented an estimated 7.5 million influenza illnesses, 105,000 influenza-associated hospitalizations, and 6300 influenza-associated deaths.”

Authors conducted an analysis to further explore influenza hospitalization rates and vaccination coverage by race and ethnicity from 2010-2011 through the 2021-2022 seasons. They also investigated influenza vaccination coverage stratified by race and ethnicity and health care access variables for the 2021–2022 season and possible reasons for observed disparities.

The analysis derived data from population-based surveillance for laboratory-confirmed influenza-associated hospitalizations in selected states participating in the Influenza-Associated Hospitalization Surveillance Network (FluSurv-NET) from the 2009-2010 through 2021-2022 influenza seasons (excluding 2020-2021) and influenza vaccination coverage data from the Behavioral Risk Factor Surveillance System (BRFSS) from the 2010-2011 through 2021-2022 influenza seasons.

“BRFSS is a state-based random-digit–dialed cellular and landline telephone survey that collects information on various health conditions and risk behaviors from one randomly selected adult aged 18 years or older in a household,” the authors explained.

From 2009-2010 through 2021-2022 (excluding 2020-2021), age-adjusted influenza-associated hospitalization rates per 100,000 population were shown to be higher among non-Hispanic Black (Black) (rate, 78.2; rate ratio [RR], 1.8), American Indian or Alaska Native (AI/AN) (rate, 54.6; RR, 1.3), and Hispanic (rate, 50.3; RR, 1.2) adults compared with the rate among White adults (rate, 43.0), whereas Asian or Pacific Islander (API) adults showed reduced rates (rate, 34.5).

Some variations in age-adjusted influenza-associated hospitalization rates per 100,000 population were cited by influenza season:

• During most influenza seasons, age-adjusted hospitalization rates were highest among Black adults, ranging from 1.5 to 2.4 times the rates among White adults.
• During the 2011-2012 and 2021-2022 seasons, the highest influenza-associated hospitalization rates were among AI/AN adults, with age-adjusted rates 2.7 times those in White adults.
• Age-adjusted hospitalization rates among Hispanic adults were 2.1 times those among White adults in 2009-2010 and 2021-2022.
• In every season except 2011-2012, API adults had the lowest hospitalization rates among all racial and ethnic groups, from 60% to 90% of those among White adults.

Overall, vaccination coverage in the 2021-2022 influenza season was 49.4% among adults, which varied by race and ethnicity. Specifically, influenza vaccination coverage for the 2021-2022 influenza season showed that coverage was lower among Hispanic (37.9%), AI/AN (40.9%), Black (42.0%), and other/multiple race (42.6%) adults compared with that among White (53.9%) and non-Hispanic Asian (Asian) (54.2%) adults.

Moreover, coverage was found to be consistently higher among White and Asian adults compared with that among Black and Hispanic adults since the 2010-2011 season. Disparites in vaccination coverage by race and ethnicity were reported among those with and without medical insurance, a personal health care provider, and a routine medical checkup in the past year.

Compared with White adults, Hispanic adults were less likely to have medical insurance, and Hispanic, AI/AN, and multiracial adults and adults of other races were less likely to have a personal health care provider and a medical checkup in the past year.

Among adults with medical insurance, a personal health care provider, and a routine medical checkup in the past year, and in most age and education strata, influenza vaccination coverage remained higher among White adults than among Black, Hispanic, AI/AN, and multiracial adults and adults of other races.

In response to the study findings, researchers said that health care providers should assess patient vaccination status at all medical visits and offer all recommended vaccines.

“Tailored programmatic efforts to provide influenza vaccination through nontraditional settings, along with national and community-level efforts to improve awareness of the importance of influenza vaccination in preventing illness, hospitalization, and death among racial and ethnic minority communities might help address health care access barriers and improve vaccine confidence, leading to decreases in disparities in influenza vaccination coverage and disease severity,” they concluded.

Reference

Black CL, O’Halloran A, Hung M, et al. Vital Signs: Influenza hospitalizations and vaccination coverage by race and ethnicity—United States, 2009–10 through 2021–22 influenza seasons. MMWR Morb Mortal Wkly Rep. Published online October 18, 2022. doi:10.15585/mmwr.mm7143e1