B0008609 Blood clotA new study published online in Vaccine, ‘Influenza and pneumococcal vaccination and risk of stroke or transient ischaemic attack—Matched case control study’, shows a strong association between influenza vaccination and a reduction in risk of stroke. The study team were researchers from the Lincoln Institute of Health, Professor Niro Siriwardena and Dr Zahid Asghar based at the Community and Health Research Unit at the University of Lincoln in collaboration with Dr Carol Coupland from Community Health Sciences at the University of Nottingham.

VLUU L110, M110  / Samsung L110, M110The study used a matched case control design involving analysis of data from almost 100000 patients recorded on the Clinical Practice Research Datalink (previously the General Practice Research Database). The investigators found that within season influenza vaccination was associated with a 24% reduction in risk of stroke. In contrast influenza vaccination was not associated with a reduction in risk of transient ischaemic attack (TIA) and pneumococcal vaccination was not associated with reduced risk of stroke or TIA.

fluvirusThe study was based on the finding from a number of studies that strokes (and heart attacks) can follow soon after episodes of influenza or other respiratory infection. Prof. Siriwardena and Dr Coupland have previously published research showing a similar association between influenza and reduction in risk of heart attack (acute myocardial infarction) published in the Canadian Medical Association Journal and Vaccine.