FDA intends to put its most serious warning on Covid vaccines, sources say

By Ben Tinker, Brenda Goodman, Meg Tirrell, CNN (CNN) — The US Food and Drug Administration intends to put a “black box” warning on Covid-19 vaccines, according to two people familiar with the agency’s plans. A boxed warning, which appears at the top of prescribing information for medicines, is the agency’s most serious, designed to