The Claim:
Safety signals seem to indicate that the Pfizer mRNA vaccine may be connected to stroke risk in people over 65 years old.
The Facts:
The Vaccine Safety Datalink (VSD) is one system that monitors vaccine safety in the general population. A few days ago, the CDC announced that Pfizer COVID vaccine, through VSD monitoring, “met the statistical criteria to prompt additional investigation into whether there was a safety concern for ischemic stroke in people ages 65.”
Programs like these are designed to catch events that may arise in the general population that may not have been caught in initial trials, but because of the way these systems collect data, they may also capture coincidental or confounding events— separate events not related to the vaccine causing these strokes.
These monitoring programs do highlight areas, such as this, that warrant further investigation into these links to try to determine if there actually is a causal relationship between the vaccine and ischemic strokes. As it is, none of the other US-based sentinel programs, nor any global safety monitoring system, has picked up any increase in ischemic stroke after the bivalent vaccine
The CDC believes it unlikely that the signal indicates an actual causal relationship. The CDC and FDA will continue to monitor and evaluate data from VSD and other safety systems, as they always do.