What Parents Need to Know About the C.D.C.’s Covid School Guidelines

With less than a month to go before many schools begin reopening for the fall, the Centers for Disease Control and Prevention on Friday released new guidelines for preventing Covid-19 transmission in schools.

The guidelines outline numerous strategies that schools can take to help keep students, teachers and staff members safe, including masking, weekly screening testing and social distancing. But the agency also stressed that schools should fully reopen even if they were not able to put in effect all of these measures.

The agency also left much of the decision-making up to local officials, urging them to consider community transmission rates, vaccination coverage and other factors. This approach won praise from some experts, who said that this more nuanced approach makes sense at this stage of the pandemic — but criticism from others, who said that state and local officials were not equipped to make those judgments and needed clearer guidance.

Here are answers to some common questions about the new guidance.

Can my child go back to school full-time in the fall?

Almost certainly. The new recommendations make clear that reopening schools is a priority and that schools should not remain closed just because they cannot take all of the recommended precautions.

Many families have struggled with remote instruction, which has forced parents to make do without traditional child care and left many children struggling to learn. Preliminary research suggests that the pandemic has widened inequities in education, with students of color falling further behind, compared with white students, and low-income students showing fewer gains, compared with their peers.

“I really appreciated the top-line focus on the most important thing — that we need to have in person learning,” said Dr. Benjamin Linas, an infectious disease specialist at Boston University.

Virtually all of the nation’s major school districts plan to offer regular in-person instruction in the fall, and some are not giving parents a choice. New York City public schools, the nation’s largest school system, will not offer a remote learning option in the fall.

Will they have to wear a mask?

It depends.

The guidelines recommend that children ages 2 or older who are not fully vaccinated should wear a mask indoors — but imply that fully vaccinated students generally do not need to wear masks in the classroom.

But the C.D.C. also notes that some schools may choose to require everyone to wear masks. On Friday, California said it planned to do just that. (At least eight states, on the other hand, have already forbidden mask mandates.)

Even when such universal masking rules are in place, exceptions should be made for students and staff members with disabilities that make wearing a mask difficult, the guidelines said. “I do appreciate that they mentioned that some kids can’t wear them,” said Jennifer Nuzzo, an epidemiologist at Johns Hopkins University. “I think that’s really important.”

Masks are not generally needed outdoors, the agency said, except in limited circumstances, such as in crowded settings in areas where local transmission rates are high.

What about social distancing?

The agency recommended that students remain at least three feet apart from one another in the classroom, consistent with earlier guidance. Some studies have suggested that three feet of distance is enough to keep students safe when other precautions are in place.

But the agency made it clear than schools that do not have the space to keep students so far apart should reopen anyway. In those cases, the guidelines said, it is particularly important to adopt other precautions, including masking, frequent virus testing and improved ventilation.

The guidelines also recommend that students remain at least six feet apart from teachers and staff and that unvaccinated teachers and staff remain six feet apart from one another. A C.D.C. official said this recommendation was based on the fact that the studies that suggested three feet of distance could be safe had assessed the amount of space only between students, and not between them and adults.

But some experts said that they found the varied distancing suggestions hard to follow and that schools would need clearer guidelines. “I’m really confused,” Dr. Nuzzo said. “And I can imagine that school districts that, frankly, need everything spelled out for them clearly — and not in a way that’s subject to interpretation — are going to be really confused.”

Will vaccines be mandated?

There is currently no major effort to mandate vaccines in K-12 schools, though that could change over time.

Right now, only children 12 and up are eligible for the vaccine, leaving a huge segment of the younger student population unprotected.

And the shots, including the Pfizer-BioNTech vaccine, which is the only one available for 12- to 15-year-olds, were approved under emergency use authorization. Until vaccines are given full approval by the Food and Drug Administration, the timing of which is unclear, experts believe it’s unlikely that vaccines will be required for school attendance.

“A vaccine mandate is always a political battle,” said Dorit Reiss, a law professor at the University of California, Hastings College of the Law in San Francisco, who said that states were unlikely to push forward with mandates until a vaccine had been authorized for students of all ages, and potentially until there was full approval. “I just don’t see legislators wanting to go through this twice.”

But the United States has a long history of requiring students to be vaccinated for certain diseases — from polio to measles — and experts believe Covid-19 is likely to join the list at some point.

In the meantime, it’s possible that schools could ask about the status of older students who are eligible for the vaccine. Chicago Public Schools, for example, has said it plans to ask families to submit Covid-19 vaccine information.

“I think you can certainly say, ‘We need to know if you are vaccinated,’” said Eric A. Feldman, a professor of medical ethics and health policy at the University of Pennsylvania Carey Law School. “If you are, then X, Y and Z rules apply to you, and if you are not, a different set of rules will apply to you.”

As for teachers, employers generally have the right to inquire about immunization status and even require vaccination for employees, experts say, though the effort in schools may be complicated by teachers’ unions.

The C.D.C. guidelines note that schools may offer “modified job responsibilities” for teachers or staff members who have not been fully vaccinated and who are at higher risk for serious Covid-19.

When can my elementary schooler be vaccinated?

Probably sometime this fall. Pfizer has said that it plans to apply this fall for emergency authorization of its vaccine for children between 5 and 11.

Moderna has said that the results from its clinical trial of young children are expected before the end of the year. The company last month applied for authorization for use of its vaccine in 12- to 17-year-olds.

How worried should I be about the Delta variant?

Delta, which is now the dominant variant of the virus in the United States, is highly contagious and has rapidly spread through the country in recent weeks.

Fortunately, the vaccines still provide good protection against the variant, especially against the worst outcomes, like hospitalization and death. “Folks who are vaccinated don’t need to have personal fear of Delta,” Dr. Linas said.

But the variant may fuel outbreaks in unvaccinated communities and populations.

“We are vaccinating more people every day, but we are not on a trajectory to be able to interrupt transmission by the fall,” said Dr. Sean O’Leary, a pediatric infectious disease specialist in Colorado. “Unless we can do that, just about everyone I know in the field is very concerned about a fall surge.”

Children are far less likely than adults to become ill from the virus or its variants. Fewer than 2 percent of children with Covid-19 end up in the hospital, and even fewer — .03 percent of cases or less — have died, according to the American Academy of Pediatrics. A small percentage may also develop a rare but potentially serious inflammatory condition.

The emergence of the Delta variant is an urgent reason to continue a variety of mitigation measures in elementary schools in particular, said Dr. Linas, who has an 11-year-old daughter who is not yet vaccinated.

What other precautions does the agency recommend?

The agency recommends what it calls a “layered” approach, suggesting that schools combine multiple mitigation strategies to reduce risk. (This has also been called the “Swiss cheese model.”)

In addition to masking, distancing and vaccination, schools could put in effect regular screening testing for the virus. Fully vaccinated students and staff members do not need to participate in screening programs or quarantine if they have been in close contact with someone with Covid-19 unless they have symptoms, according to the guidelines.

The guidelines also note the importance of ventilation, encouraging schools to bring more fresh air inside by opening doors and windows or changing the HVAC settings. “I’m glad to see ventilation called out specifically as a stand-alone item,” said Joseph Allen, an expert on healthy buildings at Harvard T.H. Chan School of Public Health. “We’ve been talking about this for 18 months at this point.”

Why isn’t the C.D.C. setting specific standards for schools?

At this stage of the pandemic, the agency said, one set of overarching rules does not make sense. Vaccination rates vary enormously across the country, and communities with low vaccine coverage may see significant outbreaks, especially as Delta spreads.

The guidance “correctly recognizes that a top-down, one-size-fits-all approach is not the best at this stage of the pandemic,” Dr. Allen said. “The guidance in Vermont and Massachusetts, where vaccination rates are high and case counts are low, should be different than in states where the opposite is happening.”

The agency recommends that officials make decisions about which precautions to apply based on local conditions, including vaccination rates, levels of community virus transmission and whether a regular testing program is in place.

Although many experts said that a local approach makes good scientific sense, flexibility also comes with risks.

The lack of clear, specific guidelines is likely to leave some districts unsure how to proceed and may lead to protracted political fights over exactly how to reopen, Dr. Nuzzo said.

Ultimately, experts predicted that a patchwork of different guidelines and requirements will emerge across the country.

“Quite honestly, I expect we’ll see exactly what we saw last year,” Dr. Allen said. “And in states that are predominantly blue states, we’ll see a very different approach to schools, even though vaccination rates are higher, than we will see in the more traditional red states, where vaccination rates have been lower and for the most part they kept schools open last year with very minimal controls.”