People vaccinated against the flu have a 12% lower risk of stroke
A study finds that influenza vaccination is associated with a reduced risk of stroke. Studies have shown that having the flu increases the risk of stroke, but whether getting the flu vaccine helps prevent stroke is a research topic.
A team of researchers from Alcala University in Madrid, Spain, focused on ischemic stroke, the most common type of stroke, caused by limited blood flow to the brain.
The researchers looked at a Spanish medical database of people who were at least 40 years old and had their first stroke in the past 14 years. Then, each stroke patient was compared with five people of the same age and sex. The database included 71,610 patients who did not have a stroke and 14,322 who did. They also looked at whether stroke patients received the flu vaccine at least 14 days before the stroke, and those without a stroke on the same day.
Among those who had had a stroke, 41.4% had the flu shot, and among those who did not have a stroke, 40.5% had the flu shot. People vaccinated against the flu are older and more likely to have other conditions that can cause stroke, such as high blood pressure and high cholesterol. When the researchers adjusted for these factors, they found that people who got the flu shot were 12 percent less likely to have a stroke than those who didn’t.
When the researchers looked at how the pneumonia vaccine affected the risk of stroke, they found that it had no preventive effect.
Professor Francisco de Abajo, who led the study, said: “It’s another reason why people at high risk of stroke should get a flu shot every year.
Because this study is an observational study, it cannot prove that getting a flu shot reduces the risk of stroke. It just shows the relevance. There may also be other factors that can affect the risk of stroke.
The study was published in the journal Neurology. The original title is ‘Influenza Vaccination and Risk of Ischemic Stroke: A Population-Based Case-Control Study.