Study finds correlation between flu vaccination and decreased risk of stroke

A study recently conducted by researchers from the University of Lincoln and The University of Nottingham, United Kingdom, found a correlation between patients who received the flu vaccine and a decreased risk of stroke.

The study, which was published in the Vaccine journal, found that patients who were vaccinated against the influenza virus early in the flu season showed a 24 percent decrease in risk of stroke. The study's researchers also found a correlation between flu vaccination and decreased risk of heart attack in 2010.

"The causes of stroke are not fully understood," University of Lincoln Professor, Research Lead with Lincolnshire Community Health Services NHS Trust and Lead Investigator Niro Siriwardena said. "Classical risk factors like age, smoking and high blood pressure can account for just over half of all cases. We know that cardiovascular diseases tend to hit during winter and that the risks may be heightened by respiratory infections such as flu."

The researchers analyzed the health records of 47,000 patients who suffered a stroke or transient ischaemic attack between 2001 and 2009 and looked for a link between risk of stroke and flu and pneumococcal vaccination.

The research team found no correlation between stroke and pneumococcal vaccination but a correlation was found between reduced risk of stroke and early flu vaccination.

"Further experimental studies would be needed to better understand the relationship between flu vaccination and stroke risk," Siriwardena said. "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."