Coronavirus: Pfizer-BioNTech latest vaccine could be linked to stroke, US finds
- A monitoring system uncovered a possible safety issue in which people 65 and older are more likely to have a stroke 21 days after the shot
- The FDA said other large studies and other countries’ databases have not flagged this issue and that it requires more investigation
A safety monitoring system flagged that US drug maker Pfizer and German partner BioNTech’s updated Covid-19 shot could be linked to a type of brain stroke in older adults, according to preliminary data analysed by US health authorities.
The US Centres for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) said that a CDC vaccine database had uncovered a possible safety issue in which people 65 and older were more likely to have an ischemic stroke 21 days after receiving the Pfizer/BioNTech bivalent shot, compared with days 22-44.
An ischemic stroke, also known as brain ischemia, is caused by blockages in arteries that carry blood to the brain.
The FDA and CDC said that other large studies, the CDC’s Vaccine Adverse Event Reporting System, other countries’ databases and Pfizer-BioNTech’s databases had not flagged this safety issue, adding that it requires more investigation.
“Although the totality of the data currently suggests that it is very unlikely that the signal in VSD [Vaccine Safety Datalink] represents a true clinical risk, we believe it is important to share this information with the public,” the health authorities said.
