What’s Holding Up the COVID Vaccines for Children Under 5?

As the United States relaxes pandemic restrictions, advising some 70% of Americans they no longer need to wear a mask, many parents of young children are desperate to know when they can expect a vaccine to be authorized for kids under 5.

But opaque communication from the U.S. Food and Drug Administration and drugmakers, on top of whiplash over the shifting timeline and unexpected delays, has led to confusion and angst. Some parents are obsessively tracking every press release, investor report and social media announcement to glean information, and a few have...