Stroke Risk After COVID-19 Bivalent Vaccination Among US Older Adults
Registry study (n=5,397,278 ≥65yrs) found no significant association between either Pfizer or Moderna vaccines and haemorrhagic or non-haemorrhagic stroke or transient ischaemic attack in the 1-21 or 22-42 day window vs the 43-90 day control window (incidence RR range, 0.72-1.12)
Source:
Journal of the American Medical Association
SPS commentary:
A related editorial notes a previous safety signal with stroke risk and COVID vaccine. This new study, with its separate analysis of stroke outcomes where influenza vaccine was additionally received, suggests that the safety signal may be owing to the high-dose or adjuvanted influenza vaccine. It concludes the new study illustrates the value of a timely, well designed analysis and has provided reassurance about the COVID-19 boosters. Ongoing monitoring of influenza vaccines marketed for older adults will provide additional data on stroke risk. This type of timely and transparent continuous assessment should be used to enhance vaccine safety and assure the public that vaccine safety is a priority of regulatory agencies.