Should masks be required when kids return to school?

The Centers for Disease Control and Prevention last week released new guidance for schools that are planning for another academic year affected by the coronavirus pandemic. The top priority for schools, the agency said, is bringing students back into the classroom and ending distance learning wherever possible.

The endorsement of in-person learning was celebrated by many parents, educators and scientists who have tracked the difficulties that remote learning has imposed on the nation’s children and families since March of last year. The CDC outlined a variety of largely uncontroversial steps schools should...