# CDC Investigating ‘Safety Concern’ Linked to Pfizer Covid Vaccine

January 13, 2023 3:50 PM

The CDC announced Friday that it is investigating a “safety concern” linked to the use of the updated Pfizer Covid vaccine booster in seniors.

“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 said in a statement.

The CDC’s vaccine safety monitoring system detected the early signal in the bivalent booster, which is designed to inoculate against the original strain of the disease as well as omicron sub variants.

An ischemic stroke happens when a blood clot prevents blood from passing through the arteries to the brain.

“There is no evidence to conclude that ischemic stroke is associated with the use of the companies’ COVID-19 vaccines,” Pfizer and BioNTech said in a statement obtained by Politico. Pfizer also said that health officials have not found similar findings on numerous other monitoring systems in the U.S. and across the world,” Pfizer said, Reuters reported.

The signal was not identified in the Moderna version of the vaccine.

“Rapid-response investigation of the signal in the VSD raised a question of whether people 65 and older who have received the Pfizer-BioNTech COVID-19 Vaccine, Bivalent were more likely to have an ischemic stroke in the 21 days following vaccination compared with days 22-44 following vaccination,” the CDC added.

The Biden administration has been pushing for elderly Americans to stay up to date on their booster shots given that their demographic is at greatest risk of developing severe health complications from the virus.

An FDA official told the Washington Post Friday that the flagged signal in the Pfizer booster may not be cause for real alarm as it appears to be more of a statistical anomaly.

“We have looked at the totality of the evidence and there are no concerns at this time that this represents a true safety signal,” the individual told the publication. “Like with a radio, you are going to hear some static in the background,” the official said.