Dr. Marr recommended not lifting school mask mandates until after the winter holidays had passed and more school-age children had had the chance to get both of their shots. If community transmission levels are low or moderate a few weeks after school resumes in January, then, “Yeah, let’s get rid of the masks,” she said.

Seema Lakdawala, a respiratory virus expert at the University of Pittsburgh, imagined a similar timeline: “Maybe in February, we can say goodbye to masks.”

Other experts were reluctant to provide a date. Dr. Rimoin said she would like to see a more sustained reduction in cases and deaths before easing mask requirements. “We’re still seeing 1,000 people dying a day from this virus,” she said. “It’s not just a matter of comfort and ease — I mean, this is a matter of life or death for many people.”