Getting immunized early in season delivers most cardiovascular benefit, study suggests
TUESDAY, Feb. 25, 2014 (HealthDay News) -- Getting the seasonal flu shot could provide a bonus: It might also significantly reduce your risk of stroke, a new study suggests.
"We know that cardiovascular diseases tend to hit during winter, and that the risks may be heightened by respiratory infections such as flu. Our study showed a highly significant association between flu vaccination and reduced risk of stroke within the same flu season," said lead investigator Niro Siriwardena, a professor in the School of Health and Social Care at the University of Lincoln in England.
The researchers analyzed data from more than 47,000 people in the United Kingdom who suffered a stroke or mini-stroke (transient ischemic attack) between 2001 and 2009. The investigators found that having a flu shot was associated with a 24 percent lower risk of stroke. However, this association does not prove a cause-and-effect relationship.
The stroke risk reduction was strongest if a person received a shot early in the flu season, the study authors noted.
But having a flu shot was not linked to a significantly reduced risk of mini-stroke, according to the study published online recently in the journal Vaccine.
The researchers also found that pneumococcal vaccination -- which protects against infections such as pneumonia -- did not reduce the risk of stroke or mini-stroke.
"Further experimental studies would be needed to better understand the relationship between flu vaccination and stroke risk," Siriwardena said in a university news release. "However, these findings reinforce the value of the U.K.'s national flu vaccination program with reduced risk of stroke appearing to be an added health benefit."
In a previous study, the same team found that flu vaccination was linked to a lower risk of heart attack.
The U.S. National Institute of Neurological Disorders and Stroke has more about stroke (http://www.ninds.nih.gov/disorders/stroke/stroke_backgrounder.htm ).
SOURCE: University of Lincoln, news release, Feb. 20, 2014