Millions of American kids will head back to classrooms in the coming days -- just as the omicron variant is fueling record new COVID-19 case counts.
And that has many parents wondering what's safe as the most contagious variant yet sweeps the country.
"We fear that it's going to get a lot worse, between getting together for the holidays and then getting back to school," said Dr. Stanley Spinner, chief medical officer at Texas Children's Pediatrics & Texas Children's Urgent Care in Houston.
As pediatric COVID-19 hospitalizations approach record highs, some cities and school districts are taking aggressive new measures.
In Washington, DC, all public school students and staff must show proof of a negative COVID-19 test before returning from winter break.
In New York City, public school students who test positive will get a week's worth of at-home tests so they can know when it's safer to return to school.
But do vaccinated students still need to wear masks? What should families do if they can't get COVID-19 tests? Should activities like choir and basketball practice be sidelined until the omicron surge passes?
Here's how several pediatricians and health experts answered some of the most critical questions from parents:
Should kids not return to classrooms just yet?
Health experts are divided.
In areas of very high transmission, it might be too early to resume in-person learning, pediatrician Dr. Peter Hotez said.
"I wouldn't do it now," said Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine.
"You have got a screaming level of transmission in the Northeast, in New York City and Washington, DC. Trying to open schools at this point, it's hard to imagine how things will go well."
But the U.S. Department of Education is urging school districts to take safety precautions and ensure classrooms are open for in-person learning.
"It is incredibly important that all schools work to remain open for in-person learning five days a week, especially in light of the omicron variant," according to a new resource guide addressed to school leaders and obtained by CNN.
Pediatrician Dr. Paul Offit said it's important for kids to be able to stay in classrooms -- and not just for their academic health.
"There are so many advantages to on-site learning. Children need the socialization that comes with being in school," said Offit, director of the Vaccine Education Center at the Children's Hospital in Philadelphia.
He said many children also depend on school meals. And in some cases, signs of child abuse are noticed only while at school.
But many students are returning to classrooms Monday -- just two days after New Year's celebrations, said Dr. Lawrence Kleinman, vice-chair of the Department of Pediatrics at Rutgers University.
And because COVID-19 tests might not detect new cases until a few days after infection, some schools or parents might choose to delay the return for a few days to allow more time for testing, Kleinman said.
Should children get tested before coming back to school?
"Getting kids back in school has to be No. 1 -- but doing so safely has to be critical," epidemiologist Dr. Abdul El-Sayed said.
"So I do think that requiring a negative test before going back to the classroom is a prudent approach here."
But many families can't find at-home rapid tests or can't afford them. And a federal program to make millions of tests available for free doesn't start until next month.
Offit said he doesn't think children necessarily need to be tested before returning to school unless they recently had contact with someone who had COVID-19 or if they have symptoms.
"If you're otherwise healthy, you don't really need to test," he said.
But if a child has symptoms "and if you can't test them, assume it's Covid," Offit said.
"And then follow all the guidelines -- meaning quarantine until asymptomatic and mask for five days after that."
Can parents feel more confident if their kids are vaccinated?
"Definitely," pediatrician Dr. James Campbell said. "Their sigh of relief should be knowing ... that even if a child gets a breakthrough infection, they're likely only to get cold symptoms from it."
While omicron is more contagious than any previous variant, children who are vaccinated have a major advantage.
"In the past, they didn't have access to a vaccine or weren't vaccinated, they would have had a higher risk of potentially being hospitalized," said Campbell, a professor of pediatrics and pediatric infectious diseases specialist at the University of Maryland. "But now that risk is way down by having been vaccinated -- even with this new variant."
Early studies suggest omicron causes less severe disease than the delta variant -- which fueled record-high COVID-19 hospitalizations among children at the beginning of this school year, when vaccinations were not yet available for kids 5 to 11 years old.
But because omicron is much more contagious than delta, doctors say the raw number of children hospitalized in the coming months could be higher.
And almost all children currently hospitalized for COVID-19 are not vaccinated, the president of the American Academy of Pediatrics said.
"What we're hearing from hospitals, really across the nation -- and this is very consistent -- is that the vast majority of the children who are being admitted are unvaccinated," Dr. Lee Savio Beers told CNN Thursday.
"Being unvaccinated increases your risk for hospitalization significantly."
For children not yet fully vaccinated, doctors say other safety measures become even more important.
In some cases, children who start with mild or no symptoms from COVID-19 end up hospitalized weeks or months later with a condition called MIS-C -- multisystem inflammatory syndrome in children.
MIS-C is "a rare but serious condition associated with COVID-19 in which different body parts become inflamed, including the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal organs," the U.S. Centers for Disease Control and Prevention said.
And long-term COVID-19 complications can be significant for children -- even for some who initially had mild or no symptoms, the American Academy of Pediatrics said.
Should fully vaccinated children still wear masks in school?
Every pediatrician interviewed for this article said yes.
"We have layers of protection. And getting vaccinated is maybe the most important of those layers," Kleinman said.
"But it's not fully sufficient because it's imperfect. They're all imperfect layers," he said.
"This is a Swiss cheese model ... each (layer) has the holes in it, like Swiss cheese."
So while the vaccination layer has the smallest holes, other layers -- such as masking and distancing -- are also important, Kleinman said.
Also, it's not yet clear how much vaccinated children might be able to spread the omicron variant to others -- such as younger siblings who are too young to get vaccinated, Kleinman said.
While some vaccinated children might be disappointed to hear they should still wear a mask in school, "simple explanations work quite well with them," Campbell said.
"And that is the virus has gotten smarter. And it's infecting people better. Your vaccine is definitely going to protect," he said.
"But you could still get infected, meaning you could still get a cold, you can still get a fever. You can still feel sick a little bit."
There's also a broader reason why students should avoid getting infected -- even if they don't get sick, Campbell said.
Reducing infections is critical to help prevent new variants that could prolong this pandemic even further.
"If the virus is kind of beaten down to the point where there's very little circulation, the less circulation, then the less replication," Campbell said. "The less replication of the virus, the fewer chances it has to mutate."
What kinds of masks should kids be wearing now?
Much has changed since the last school year. The once-dominant alpha variant has been replaced by the more contagious delta variant, which has been surpassed by the even more contagious omicron variant.
That means basic cloth masks with gaps around the edges won't cut it anymore, said Mercedes Carnethon, vice chair of preventive medicine at Northwestern University Feinberg School of Medicine.
"They're pretty effective -- at spreading Covid," she said.
Instead, three-ply surgical masks with an adjustable nose wire and KN95 masks are much more helpful, Carnethon said.
"That's really what you need to stop air from leaking out," she said.
More than ever, a good fit is important, Carnethon said. One way to test the fit is to have a child put on a mask and then put on glasses or sunglasses. If they can feel air escaping or fogging up the glasses, it's not a good fit.
Should activities such as choir and basketball be sidelined for now?
"I think that's a really hard question," Kleinman said.
Ideally, students in activities involving heavy breathing will be vaccinated -- along with coaches, directors and any other adults nearby, he said.
"Testing is the other thing that is a friend to all these activities," Kleinman said.
The answer should also depend on how rampantly COVID-19 is spreading in a community, Campbell said.
"They may just have to say, 'Well, we're going to have to suspend (certain activities) for some time,'" he said.
"But I think just blanket stopping all after-school activities is probably a mistake at this point."
Children who are frustrated by ongoing COVID-19 safety precautions should take solace knowing they might not last too much longer, Offit said.
Like several other health experts, Offit said he expects the current surge in COVID-19 cases to start declining within the next few months.
"So just hang in there for six weeks if you can," he said. And by then, more children will likely be vaccinated, too.