U.S. regulators on Friday put the brakes on their push to speed Pfizer's COVID-19 vaccine to children under 5, creating major uncertainty about how soon the shots could become available.
The Food and Drug Administration had urged Pfizer and its partner BioNTech to apply for authorization of extra-low doses of its vaccine for the youngest children before studies were even finished — citing the toll the omicron variant has taken on children.
Next week, FDA advisers were supposed to publicly debate if youngsters should starting getting two shots before it's clear if they'd actually need a third.
But Friday, the FDA reversed course and said it had become clear it needed to wait for data on how well that third shot works for this age group. Pfizer said in a statement that it expected the data by early April.