Because respiratory infections such as the flu can increase the risk of cardiovascular diseases, receiving the seasonal flu vaccine can reduce the risk of stroke by almost a quarter, says a new study from the University of Lincoln and The University of Nottingham in the United Kingdom as published in the journal Vaccine.
Influenza, or the flu, is a contagious respiratory illness caused by various flu viruses. Symptoms of the flu include fever, chills, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, and fatigue. Complications of the flu include pneumonia, bronchitis, sinus and ear infections, and death. Influenza is not the same as the stomach flu, which is characterized by nausea, vomiting, and diarrhea.
In 2010, the same research team discovered a decreased risk of heart attack as a result of seasonal flu vaccination.
States lead researcher Professor Niro Siriwardena, Professor of Primary and Pre-hospital Healthcare in the School of Health and Social Care at the University of Lincoln and GP and Research Lead with Lincolnshire Community Health Services NHS Trust:
“The causes of stroke are not fully understood. 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. Our study showed a highly significant association between flu vaccination and reduced risk of stroke within the same flu season. The results were consistent with our previous research into heart attack risk.”
Using data more than 47,000 patients who experienced a stroke or TIA (transient ischaemic attack, or “mini stroke”) between 2001 and 2009 drawn from the UK’s national General Practice Research Database (now the Clinical Practice Research Datalink), the researchers investigated the associations between influenza or pneumococcal vaccination and stroke or TIA. Using matched case-control design, the researchers compared the stroke patients with control patients.
According to the study, receiving a flu shot reduces the risk of stroke by 24 percent. The flu shot did not reduce the risk of TIA, and the pneumococcal vaccine did not reduce the risk of stroke or TIA.
Comments Professor Siriwardena, “Further experimental studies would be needed to better understand the relationship between flu vaccination and stroke risk. However, these findings reinforce the value of the UK’s national flu vaccination programme with reduced risk of stroke appearing to be an added health benefit.”
Not only does the flu shot reduce the risk of influenza, but the flu shot also reduces the risk of stroke by almost a quarter.
Influenza and pneumococcal vaccination and risk of stroke or transient ischaemic attack: Matched case control study: http://www.sciencedirect.com/science/article/pii/S0264410X14000619
Seasonal flu vaccine may cut stroke risk: http://www.medicalnewstoday.com/releases/273037.php
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