Most U.S. schools do not yet meet Biden’s demand for testing and vaccines.

For schools to stay open and safe, President Biden said last Thursday, they need to require universal masking, vaccinations for teachers and staff and regular tests for unvaccinated people. So far, the largest U.S. districts are succeeding at masking, but only a minority are implementing the others.

Out of 100 large districts, including the biggest urban districts in every state, nine in 10 are requiring students to wear masks, according to the Center on Reinventing Public Education at the University of Washington. Just one-quarter are requiring teachers to be vaccinated. Fifteen are regularly testing students. And student quarantine policies are generally much less strict than they were last spring.

New York City public schools, which start Monday, are an anomaly on several measures, including the absence of a remote option and a more strict approach with quarantines.

So far this school year, none of the 100 districts have stopped offering full-time, in-person school for Covid-19 reasons. But many plans were hastily revised as school neared and as the Delta variant spread.

The biggest change has been offering a remote option to families not ready for a return to school. Ninety-four of the 100 large districts now have that option — all but those in New York City; Newark; El Paso; Bridgeport, Conn.; Dayton, Ohio; and Manchester, N.H. In more than half of those, it’s available to all students.

Another change has been in mask rules. Eighty-nine of the 100 large districts now require masks, up from half in mid-August.

Twenty-seven of the districts require staff to be vaccinated, up from four in mid-August. Just one, Los Angeles, is requiring vaccines for eligible students, as of last week. Fifteen are testing students regularly, up from seven in mid-August.

Quarantine policies are perhaps the biggest change from last year. Now in many instances, students who share a classroom with an infected person will not have to stay home to quarantine — and their families will not be informed that a classmate was infected.