Racial Disparities Still Prevalent for Influenza Vaccine Rates for Older Adults

Salah Mahmud (University of Manitoba)

New research shows that older minorities in the US are less likely to receive the influenza vaccine in the US.

A team of researchers, led by Salah Mahmud, Canada Research Chair and Professor of Community Health Sciences and Pharmacy at the University of Manitoba, analyzed anonymized data from health care records of individuals in receipt of Medicare benefits between July 2015 and June 2016.

The researchers used 26.5 million Medicare beneficiaries during the 2015-16 influenza seasons to find that Hispanics (29.1%), African-Americans (32.6%, and Asian-Americans (47.6%) were less likely to receive a flu vaccine than Caucasians (49.4%).

High Dose Vaccines

For the individuals who received the vaccine, there was inequities found in who was given the more effective for individuals aged 65 and older High Dose Vaccine (HDV).

More than half of the vaccinated Caucasian individuals (53.8%), significantly more than other groups—Hispanics (37.8%), African-Americans (41.1%), and Asian-Americans (40.3%) (African-Americans: OR, 0.59; 95% CI, 0.59-0.60; Asian-American: OR, 0.58; 95% CI, 0.58-0.59; Hispanic: OR, 0.52; 95% CI, 0.52-0.53; Other: OR, 0.70; 95% CI, 0.70-0.71).

The researchers also adjusted for region, income, chronic conditions, and patterns of health care use and still found similar disparities, showing that minorities were still 26-32% less likely to receive the HDV compared to Caucasians (African-American: OR, 0.68; 95% CI,[0.68-0.69; Asian-American: OR, 0.71; 95% CI, 0.71-0.72; Hispanic: OR, 0.74; 95% CI, 0.73-0.74; Other: OR, 0.73; 95% CI, 0.72-0.74).

In addition, the researchers found women were more likely to get the influenza vaccine than men (49.5% women vs 44.8% men), but were slightly less likely to receive the HDV (52.1% women vs 53.6% men).

“Our finding that racial and ethnic disparities persist even among people who received a flu vaccine rules out the often-cited justifications for inequities in vaccine uptake, such as higher levels of vaccine hesitancy and distrust of public institutions among minority groups,” Mahmud said in a statement. “Rather, our study points to deeply rooted structural deficits that systematically hamper access to influenza vaccination, which may be have serious implications for our ability to effectively roll out the COVID-19 vaccination program.”

Adults older than 65 are currently recommended the seasonal flu vaccine in the US, with the high dose version encouraged since it was approved in 2009. This vaccine has shown to be more effective in older adults, eliciting a stronger immune response.

Limitations

While the results paint a stark picture, there were some limitations associated with the study. For example, the study only included data from the Medicare database, which could underestimate overall levels of vaccine uptake because it might not include those administered during mass vaccination campaigns.

There is also the possibility the findings might not be generalizable to other flu seasons.

In an associated editorial, Maria Sundaram, PhD, University of Toronto, and John R. Pamplin II, PhD, New York University, who were not involved in the study, said the study could drive new initiatives and policy discussions.

“The study by Mahmud and colleagues highlights the reality that public health programs that are implemented without explicit consideration of racial equity frequently produce inequities downstream,” they said. “In some cases, the magnitude of these disparities might eclipse the effectiveness of the program itself. Interventions to resolve these disparities should therefore be a primary focus among influenza epidemiology research, lest we forget a core tenet of vaccine epidemiology: vaccines do not save lives— vaccinations do.”