The previous social distancing recommendation, brought on by the COVID-19 pandemic, was that students be spaced six feet apart (and wear masks). That requirement proved a barrier to many schools. As it was, a great many students in the U.S. spent much of 2020 learning by means other than in-person instruction. Online classes proliferated, as did a mixture of digital and print-based instruction.

The largest school district in the U.S. is in New York City. Officials in that district approved three-foot distancing for students of elementary schools and of prekindergarten programs, as well as students who have complex disabilities. Pending are reviews of the three-foot distancing requirement for older students.

Similarly, in Los Angeles, home to the nation's second-largest school district, students will be able to attend some in-person classes beginning in April. (They must still wear masks while at school, as must their teachers.)

Other schools across the country have stuck with the six-foot requirement for in-person instruction or maintained virtual instruction.