Flu vaccination may reduce stroke risk, study suggests

Getting a flu shot may offer an added benefit. A recent study published in Stroke, an American Heart Association journal, suggests flu vaccination might lower the chances of stroke among adults, especially people under 45.

Dr. Gyanendra Kumar, a Mayo Clinic neurologist not involved in the study, says it’s long been known that respiratory infections increase the risk of stroke in the days following infection.

“Respiratory infections, in the first three days after the onset of the infection, increase the risk of a stroke,” Kumar said.

There are several theories on why getting the flu might increase the chances of stroke.

“Some of these are increased hypercoagulable state, a transient period where you have a greater predisposition to form clots,” Kumar said.

When clots form, they can block blood flow to the brain.

There are two broad subtypes of strokes: ischemic, which is the clotting kind, and hemorrhagic, or the bleeding type. The vast majority of strokes, close to 90 percent, are ischemic, Kumar said.

More than 140,000 Americans die from strokes each year, according to the Centers for Disease Control and Prevention. That’s why reducing risks is so essential, and the flu shot may be another tool.