Local 12: Study: COVID-19, flu shots may increase stroke risk in seniors when given together
UC expert questions the design of the study
A study recently released by the Food and Drug Administration is raising questions about a potential connection to stroke risk. It found flu and COVID-19 vaccines may slightly increase the risk in seniors of stroke caused by blood clots in the brain.
The study suggests that this is a particular concern when the shots are administered at the same time.
In a story produced by Local 12, Carl Fichtenbaum, MD, of the Division of Infectious Diseases at the UC College of Medicine questioned the methodology of the research.
Carl Fichtenbaum, MD, of the Division of Infectious Diseases at the UC College of Medicine/Photo/Joe Fuqua II/UC Marketing + Brand
"I think the problem with this kind of study from a design is this study only looked at people who are vaccinated," Fichtenbaum said. "And what it was looking at was somebody more likely to have an event early on versus later on. And so, I think that is probably not the optimal study design.”
FDA researchers analyzed the data from Medicare claims and found that the increase happened in adults who are 85 and older. This is the second study to find that COVID-19 and flu shots when given together put seniors at a higher risk for stroke. There are three cases for every 100,000 doses given.
The high-dose flu vaccine, which is designed to rev up the immune system, was found to be the culprit in these results.
"There's five other studies that have looked at this in national databases throughout the world and found exactly the opposite -- no real risk whatsoever,” Fichtenbaum said. “And remember this study has not been peer-reviewed, and so that there may be some alterations and changes when it gets an opportunity to go through the normal review process, and the conclusions of this study may have to be a little bit altered based upon how the reviewers view the data."
Lead photo/Colleen Kelley/UC Marketing + Brand.
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