Receiving the seasonal influenza vaccination could reduce the risk of suffering a stroke by almost a quarter, according to a report by UK researchers. The findings, from a study carried out by the Universities of Lincoln and Nottingham showed that patients who had been vaccinated against influenza were 24% less likely to suffer a stroke in the same ’flu season.
The study, known as IPVASTIA, analysed records of more than 47,000 patients who had suffered a stroke or TIA between 2001 and 2009. Data were drawn from the UK’s national General Practice Research Database (now the Clinical Practice Research Datalink).
The analysis showed that ’flu vaccination was associated with a 24% reduction in risk of stroke. The reduction was strongest if the vaccination was given early in the flu season. There was no statistically significant change in risk of TIA with ’flu vaccination.
The investigators acknowledge that this type of retrospective study design, although widely used in health research to identify risk factors in large samples, cannot prove direct cause-and-effect relationships.
Take-up of the ’flu vaccination programme across England is lower than national targets, at 74% for over- 65s in 2011/12 and around 52% for under-65s in at-risk groups.