CDC identifies potential side effects in Pfizer COVID-19 vaccine

The Centers for Disease Control and Prevention on Friday announced that the data it had collected merited an investigation into potential stroke risks for recipients for the Pfizer-BioNTech COVID-19 vaccine.

"Following the availability and use of the updated (bivalent) COVID-19 vaccines, CDC’s Vaccine Safety Datalink (VSD), a near real-time surveillance system, met the statistical criteria to prompt additional investigation into whether there was a safety concern for ischemic stroke in people ages 65 and older who received the Pfizer-BioNTech COVID-19 Vaccine, Bivalent," the agency wrote in a press release.

It further noted that the "preliminary signal" that prompted the investigation of the Pfizer vaccine has not been identified in the Moderna vaccine.

The agency contended that it is "very unlikely that the signal in VSD represents a true clinical risk" and does not recommend any changes to its vaccine practices at this time.