Doctors still recommend Americans receive both shots

Published 10/26/23 12:45 PM Mansur Shaheen The Messenger

People over the age of 85 that receive the COVID-19 vaccine at the same time as certain types of flu shots are at an increased risk of stroke, according to a new Food and Drug Administration (FDA) study.

The findings, published in pre-print this week, analyzed Medicare claim data to determine the risk of severe adverse effects of the vaccine in people aged 65 and older. They found that people who receive the Pfizer bivalent COVID-19 vaccine and a high-dose or adjuvant flu shot on the same day were at an increased risk of having an ischemic stroke. 

The risk factor was relatively low, however, with researchers detecting three more strokes for every 100,000 people in the dataset.

This is not the first time officials have issued this type of warning surrounding the bivalent shots. In January, the FDA and Centers for Disease Control and Prevention (CDC) warned that people over 65 who received the shot were more likely to experience an ischemic stroke three to four weeks later.

This study, which has not yet been peer-reviewed, investigates that warning, finding that the risk is concentrated among the oldest Americans. 

However, researchers note that it might not have anything to do with the COVID shot, and could be possible that the flu shot holds all the blame for the increased stroke risk.

“We additionally found a slightly elevated risk of stroke following influenza vaccines administered without [also administering the] COVID-19 bivalent vaccines,” they write. “This finding suggests that the observed risk of stroke in the concomitant subgroup was likely driven by influenza vaccination alone rather than concomitant administration.”

Many leading officials have promoted receiving both the flu and COVID vaccines at the same time. Pfizer, among other manufacturers, is even developing a joint shot for both viruses. The company enlisted NFL star Travis Kelce for an advertisement promoting receiving the shots together last month.

For now, doctors and scientists still recommend Americans, especially people aged 65 and older who are most at risk of severe symptoms or death from COVID, receive the vaccine. The FDA and CDC recently approved a new set of COVID boosters too, meaning the bivalent shots this study investigated are no longer available.

“Available data do not provide clear and consistent evidence of a safety problem for ischemic stroke with bivalent mRNA Covid-19 vaccines when given alone or given simultaneously with influenza vaccines,” Tom Shimabukuro, M.D., who oversees vaccine safety at CDC, said during a presentation of the data.

Ischemic strokes account for 87% of the nearly 800,000 people who experience a stroke each year. It is caused by blood clotting which denies the brain crucial oxygen-rich blood. A person who has an ischemic stroke may suffer permanent and debilitating brain damage, and quick medical intervention is needed to prevent