Pfizer Inc. asked U.S. regulators for emergency-use authorization of a booster shot of its Covid-19 vaccine in children ages 5 to 11, setting in motion an effort to provide extra protection to kids.
Pfizer and partner BioNTech SE submitted data to the U.S. Food and Drug Administration from a late-stage study that showed a third-dose booster shot, given about 6 months after the second dose, provided a strong immune response.
