The following is an excerpt from The Vaccine Reaction.

On Jan. 13 2023, the U.S. Food and Drug Administration (FDA) and the U.S. Centers for U.S. Disease Control and Prevention (CDC)) issued a public statement regarding the identification of a preliminary safety signal for ischemic stroke among adults over the age of 65 that occurs between one to 21 days after receiving Pfizer/BioNTech’s monovalent Comirnaty messenger RNA (mRNA) Covid-19 shot and the WT/OMI BA.4/BA.5 bivalent version of it.

The safety signal was detected in the CDC’s Vaccine Safety Datalink (VSD), however, a primary analysis conducted by federal public health officials did not find elevated stroke risk following Covid bivalent shots.

The first CDC analysis evaluated the risk of the stroke following a Covid bivalent shot. The study’s sample population included 5,397,278 adults over 65 years old, who were given either the monovalent Comirnaty bivalent WT/OMI BA.4/BA.5 shot or Moderna/NIAID’s bivalent Spikevax shot.