Minneapolis [US]: According to a study published online in Neurology, the medical journal of the American Academy of Neurology, receiving an annual flu shot may reduce the risk of stroke. "Studies have shown that getting the flu increases your risk of having a stroke, but research is still being collected on whether getting the flu vaccine can help protect against a stroke," said study author Francisco J. de Abajo, MD, MPH, PhD, of the University of Alcala in Madrid, Spain.
"This observational study suggests that those who have a flu shot have a lower risk of stroke. To determine whether this is due to a protective effect of the vaccine itself or to other factors, more research is needed." The study looked at an ischemic stroke, which is caused by a blockage of blood flow to the brain and is the most common type of stroke.
For the study, researchers looked at a healthcare database in Spain and identified people who were at least 40 years old and had the first stroke over a 14-year period. Each person who had a stroke was compared to five people of the same age and sex. There were 14,322 people who had a stroke and 71,610 people who did not have a stroke. Then the researchers looked at whether people had received the influenza vaccine at least 14 days before the stroke or before that same date for those who did not have a stroke.