Throughout the whirlwind COVID-19 vaccine rollouts in the U.S., federal officials have kept a close eye on reports of adverse events. Now, after tracking potential stroke risk for Pfizer’s new shot, the government is sharing its findings.
The Centers for Disease Control and Prevention (CDC) recommends no changes to COVID-19 vaccine practices after data from its Vaccine Safety Datalink flagged a possible risk of ischemic strokes in people 65 and older who received Pfizer and BioNTech’s updated COVID-19 vaccine booster. The totality of evidence suggests a “very unlikely” clinical risk, the agency said in a Friday statement.
An ischemic stroke occurs when brain tissues can’t get oxygen or nutrients following an interruption in the brain’s blood supply.
The CDC’s Vaccine Safety Datalink, a “near real-time” surveillance system, found “statistical criteria” to warrant further investigation into the stroke risk in certain vaccine recipients, the CDC said in a Friday statement. Specifically, officials probed whether there was a higher risk of stroke in the 21 days immediately after vaccination—compared with the following 21 days—in people 65 and older.
Government agencies use multiple databases and systems to confirm their safety assessments, and the CDC said “multiple subsequent analyses have not validated this signal.” All in all, the CDC recommends no change to vaccination practices.
The CDC and the FDA will “continue to evaluate additional data from these and other vaccine safety systems,” and the data and analyses will be discussed at the upcoming meeting of the FDA’s Vaccines and Related Biological Products Advisory Committee.