Getting flu and COVID shot together still reasonable amid safety review of potential stroke risk: Experts

Older adults who received last year’s COVID booster and a high-dose version of the flu vaccine in the same visit may have a potential increased risk of stroke, according to a new FDA-funded study.

Experts urged that the results were preliminary and may be explained by other factors such as the fact that older adults are already at a higher risk for stroke due to their age.

"There is no need for panic, and emphatically no need to stop giving COVID and flu shots at the same time to older adults," said Dr. Peter Chin-Hong, an infectious diseases specialist at the University of California, San Francisco, while he reiterated that more research is needed.

The results were also not yet peer-reviewed, meaning it hasn't been vetted in the normal scientific process.

"These data should be considered by patients and their physicians, but there is no reason for alarm. The increased risk of stroke appears to be small and must be balanced against the known benefit of these vaccines in elderly individuals," said Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center.

Last year, health authorities noted a safety signal for ischemic stroke in adults over the age of 65 after receiving the bivalent COVID vaccine, prompting further research.

"Additional data are needed before we can consider these findings definitive. It is good that the FDA has made these safety data available to inform the public," Barouch said.

There was about a 20-35% increased stroke risk in older adults that received both shots in the same visits, according to the study.

"I don’t know that the risk is very meaningful on an individual patient basis," said Dr. Amesh Adalja, an infectious disease specialist at the Johns Hopkins University Center for Health Security.

Infection from COVID and flu also have been shown to increase risk of stroke as well as a host of other life-threatening outcomes linked to respiratory illnesses like pneumonia, according to Chin-Hong.

The Food and Drug Administration told ABC News in part of a statement that they remain, "confident in the safety, effectiveness and quality of the COVID-19 vaccines that the agency has authorized and approved."

"The review conducted in this preprint paper is part of our ongoing safety surveillance efforts, which utilize a variety of data sources," the statement continued.

The Centers for Disease Control and Prevention reiterated that current vaccine guidance remains the same. "The COVID-19 vaccines meet the FDA’s and CDC’s very high safety standards. Hundreds of millions of people in the United States have safely received COVID vaccines under the most intense safety monitoring in U.S. history," the agency said in part of a statement.

Experts reiterated patients should turn to their health care provider to learn about the benefits and potential risks of vaccination. Older adults choosing to get both the flu and COVID shot at the same time for convenience or in two separate visits are both reasonable decisions, Adalja explained.

"For now, I will not dissuade my mom from getting both the high dose flu shot or the COVID shot, even at the same time," Chin-Hong said.

"Ultimately we need ongoing data in other countries and in future years to inform best practice," he added.