Monitoring of COVID-19 vaccine safety is always ongoing globally (2). 🌍
When safety signals are flagged by a monitoring database it prompts further investigation of all other available databases (1).
In this case, the safety signal concerned a potential risk factor for ischemic stroke for anyone 65 years and older in the 21 days following a Pfizer bivalent booster (1).
Symptoms of ischemic stroke includes (5):
- Severe headache
- Numbness or weakness of muscle
- Trouble seeing
- Trouble walking, dizziness, loss of balance or coordination
After looking at all the data available over multiple databases it was concluded that there was no true clinical risk associated with the Pfizer bivalent vaccine at this time. However, further investigations are needed to better understand the signal origin (1).
No similar signal was identified in any available monitoring database for Moderna’s bivalent boosters (1).