CDC, FDA Flag Early Signal of Stroke Risk With Bivalent COVID Vaccine

An early signal of stroke risk was detected in older adults who received Pfizer-BioNTech’s bivalent COVID-19 vaccine, the FDA and CDC announced in a joint statement late on Friday, yet the agencies found no link in further analyses and are not recommending a change in COVID-19 vaccination practice.

According to the agencies, incidence of ischemic stroke in CDC’s Vaccine Safety Datalink (VSD) among individuals 65 and up in the 21 days following vaccination with Pfizer’s bivalent booster “met the statistical criteria to prompt additional investigation” when compared with the 22-44 days thereafter.

However, subsequent analyses of the Vaccine Adverse Event Reporting System, the Centers for Medicare & Medicaid Services database, and a preliminary study of the Veterans Affairs database turned up no signal for an increased risk with either Pfizer or Moderna’s bivalent vaccines, both of which were first authorized in late August.