US investigates potential safety signal with Pfizer Covid boosters
The FDA and the CDC are investigating a “preliminary signal” of whether there might be an increased risk of stroke for people who got Pfizer and BioNTech’s updated Covid-19 vaccine booster.
In a statement posted on the CDC’s website, the agency said its monitoring system for vaccine side effects had been triggered to look for a potential issue with the shots in people ages 65 and older.