CDC investigates Pfizer vaccine for stroke risk

The Centers for Disease Control and Prevention (CDC) says a preliminary “safety signal” of the COVID-19 vaccine has been identified and is investigating whether the Bivalent Pfizer-BioNTech vaccine poses an increased risk of ischemic stroke in people 65 and older.

In Friday’s statement, the CDC said the preliminary label has not been identified with the Bivalent Moderna COVID-19 vaccine.

“Following the availability and use of 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 concern for safety for ischemic stroke in people age 65 and older who received the Pfizer-BioNTech COVID-19 vaccine, Bivalent,” the CDC said.

“The Rapid Signal Response Investigation in VSD asked whether people 65 years of age and older who received the Pfizer-BioNTech COVID-19 vaccine, Bivalent were more likely to have an ischemic stroke at 21 days after vaccination compared to days 22-44 after vaccination’.

According to the CDC, an ischemic stroke “occurs when blood clots or other particles block blood vessels in the brain.”

In the statement, the CDC pointed out that a large study of updated bivalent vaccines by Pfizer-BioNTech “using the Centers for Medicare and Medicaid Services database did not reveal an increased risk of ischemic stroke.”

The agency also said that the Vaccine Adverse Event Reporting System (VAERS) administered by the CDC and the FDA has not seen an increase in the reporting of ischemic strokes after the updated (bivalent) vaccine.

In a statement to Fox News Digital, a Pfizer spokesperson said: “Pfizer and BioNTech have been made aware of limited reports of ischemic stroke observed in the CDC Vaccine Safety DataLink (VSD) database in people 65 years of age and older following vaccination with Omicron BA.4/BA.5 Adapted Bivalent COVID-19 Vaccine from Pfizer and BioNTech”.

“Neither Pfizer and BioNTech nor the CDC or US Food and Drug Administration (FDA) have observed similar findings in many other monitoring systems in the US and worldwide, and there is no evidence to conclude that ischemic stroke is associated with the use of companies. “Vaccines against COVID-19,” the spokesperson continued.

“Compared to published stroke incidence rates in this elderly population, the companies to date have observed a lower number of reported ischemic strokes following vaccination with the Omicron BA.4/BA.5 bivalent vaccine. CDC continues to recommend vaccination with the Pfizer-BioNTech Omicron BA.4/BA.5 adapted bivalent COVID-19 vaccine for all approved ages and indications.”

The CDC is not recommending a change in vaccine practice.

Fox News medical contributor Dr. Marc Siegel said this is not “proof” of a link between the vaccine and strokes.

“This is not proof. It’s that they see there might be a link here, and they want to investigate it, and they’re trying to be transparent,” he said.