According to a study published in the American Academy of Neurology, getting an annual flu shot can lower the risk of stroke. Dr. Francisco J. de Abajo, MD, MPH, Ph.D., of the University of Alcala in Madrid, Spain, stated that the findings of the study have highlighted that flu can increase the risk of stroke. However, he added that the observational study conducted by his team suggested that those who have had a flu shot have a lower risk of stroke, but more research is needed to determine whether this effect was due to the protective nature of the vaccine itself or other factors.

In the study, 14,322 people with a history of stroke before 14 years and 71,610 people who had not had a stroke were included. The researchers then 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. On analysing the data, it was seen that a total of 41.4% of individuals who had a stroke had received the flu shot, compared to 40.5% of those who did not have a stroke. However, the people who got the shot were more likely to be older and to have other comorbid conditions, such as high blood pressure and high cholesterol, that would make them more likely to have a stroke.

Once researchers adjusted for those factors, they found that those who received a flu shot were 12% less likely to have a stroke than those who did not. Dr. de Abajo stated that the ability to reduce the risk of stroke by taking such a simple action is very compelling. He also added that the study was an observational trial; hence, it does not prove that getting the flu shot reduces the risk of stroke, but only sheds light on the association.

(Source: https://theprint.in/health/researchers-find-flu-shot-linked-to-lower-risk-of-stroke/1120397/ )