Coronavirus Update: Pfizer and BioNTech seek FDA authorization for 3-dose vaccine for children between 6 months and 5 years old, and WHO warns that fewer tests mean fewer cases detected

Pfizer and BioNTech have asked the U.S. Food and Drug Administration to authorize their three-dose vaccine for children aged six months to five years, in a move that could add roughly 19 million young children to the program.