As the omicron variant rages, an increasing number of children are being hospitalized with COVID-19.

Across Illinois as of Jan. 5, hospitals reported 173 patients who were 17 years old or younger, according to a state public health department spokeswoman. Kids and teens made up 2% of all hospitalized patients with COVID-19 at the time.

Given that the number of pediatric hospitalizations remain statistically small, it’s a sign that many children and teens have been largely protected from getting seriously sick if they were infected with COVID-19.

Still, this is a frightening vision, and one that doctors and public health officials say is preventable.

Here’s what we know about how COVID-19 impacts kids.

Are more children getting COVID-19?

Cases are rising dramatically for kids. Since the first case of the highly contagious omicron variant was reported by Illinois public health officials one month ago, the number of newly confirmed COVID-19 cases has shot up nearly five-fold for those ages newborn to 17, to more than 11,000 cases statewide as of Jan. 7. That’s the highest level it’s been since the start of the pandemic.

For the most part, though, kids have milder cases than adults. Across the U.S., the youngest kids have consistently had some of the lowest number of cases among all age groups during the pandemic, while kids and teens have had the lowest rates of hospitalizations, according to the Centers for Disease Control and Prevention.

COVID-related deaths among kids are rare. Fewer than 20 children have died in Illinois from COVID-19, according to the state public health department spokeswoman. The majority of them were between 5 and 17 years old. When including all age groups, at least 28,000 people are confirmed to have died from COVID-19, state data show.

People tend to get sicker with the coronavirus the older they are, said Emily Oster, an economics professor at Brown University. Oster launched a newsletter during the pandemic that became a must-read for many parents who were hungry for someone to explain how COVID-19 could affect their lives.

In a recent newsletter, Oster tried to ease the minds of parents of kids younger than 5. This group isn’t eligible yet for COVID-19 vaccines.

“Deaths are extremely, extremely rare – substantially lower than deaths from car accidents, birth defects, or cancer (among other causes),” she wrote.

A child who gets COVID-19 will likely have a fever, cough or congestion, the types of symptoms that happen with other viruses.

How many kids are being hospitalized for the virus closer to home in Chicago and in Illinois?

The numbers are rising, but remain relatively small: There were fewer than 200 kids and teens hospitalized for COVID-19 this week across Illinois.

But that doesn’t lessen the blow for parents, and the health care providers who treat these young patients.

“The numbers are small depends on where you’re sitting,” said Dr. Jason Kane, a pediatric intensive care physician and director of quality and outcomes at UChicago Medicine’s Comer Children’s Hospital on the South Side. “For me, 40 percent of my ICU beds right now are filled with COVID kids. That’s insane. That’s the highest we’ve seen during the entire pandemic.”

While that may be only just over 20 kids out of 66 kids hospitalized at Comer, “that’s 20 kids in beds that can’t be used for other things that we would normally be using them for,” Kane said. “So there’s a real significant downstream consequence to any vaccine-preventable illness occupying a hospital bed.”

And there are far fewer intensive care beds for kids than for adults across the country, he said.

On Wednesday afternoon, Kane described what his ICU looked like. It was filled with unvaccinated children. Either they weren’t eligible for shots, or their parents decided against vaccinating them, Kane said. He listed the ages of some of the sickest patients with COVID-19 in the intensive care unit: 9 months, 4, 7, 13 and 17.

There were even more kids with COVID-19 who weren’t sick enough for the ICU, but sick enough to be at Comer.

“It’s not sparing anybody,” Kane said.

What scares him the most are the kids who have what’s referred to as MIS-C: multisystem inflammatory syndrome, which is a condition related to COVID-19.

“We don’t understand why it happens,” Kane said. “And it causes acute aggressive heart failure. I mean these kids look like they are dying.”

Kane wonders what happens to these kids long term. Will their hearts be damaged, and if so, how badly?

So then why do public health officials say school is safe for kids?

Because several officials say they aren’t seeing COVID-19 raging in school.

This is a bitter debate in Chicago, where public school students have been out of school since Jan. 5 after members of the Chicago Teachers Union voted to work remotely. They say schools aren’t safe. Mayor Lori Lightfoot, the city’s top doctor and the head of Chicago public schools strongly disagree. So schools have largely been closed, while parents scramble for child care.

Still, many public health officials and physicians insist school isn’t where people are mostly getting COVID-19 and spreading it. They’re likely picking it up in their own communities.

What does the data show about school spread?

The data out there can be confusing. The Illinois Department of Public Health maintains a web site that shows where people might have been exposed to COVID-19. Schools are listed as the No. 1 potential source. But, health experts caution that data is limited and isn’t definitive — it’s based on interviews contact tracers are having with just a fraction of people who’ve contracted the virus, and excludes Chicago. Further, the data indicate only where those infected say they’ve been in the past two weeks, not where they definitively contracted the virus.

The state also posts information about where school “outbreaks” have occurred, meaning three or more cases in one school from people who live in different households. There are currently 134 outbreaks statewide, and 10 at schools in Chicago, with each of those schools having fewer than five cases.That’s a fraction of the cases in Chicago during the time frame these cases were reported, when there were at least 4,000 new cases of COVID-19 among kids ages 0 to 17, according to the Chicago Department of Public Health.

Lurie Children’s Hospital, a destination in downtown Chicago for the sickest kids, has been testing students and staff in Chicago public schools since September and has yet to find signs of clusters of cases.

“When we’ve seen epidemiologic links in positive cases, it’s typically been siblings who are in different grades in the same school,” said Dr. Larry Kociolek, whose research team at Lurie is doing the testing. “And oftentimes we can track positive tests back to a household member that exposed them within the last few weeks.”

Lurie’s team is called in when there are at least five cases in a school. Since September, his team has visited 19 Chicago public schools, and tested more than 1,200 students and staff. Of those, 18 people were positive for COVID-19, he said. None had a link to school. After a review, many cases were apparently tied to kids and employees being exposed to the virus at home, Kociolek said.

A caveat: Testing was done before the omicron surge took off before the holidays, and the variant is highly contagious.

But there have been several other studies that point to COVID-19 not largely spreading in schools when mitigations are in place, such as wearing masks and social distancing.

Lurie also conducted a similar study among 11 private schools across eight ZIP codes in Chicago, and found similar conclusions.

How can parents protect their children from getting COVID-19?

For one, get vaccinated.

“What we’re seeing is real time evidence of how effective vaccines are,” said Kociolek, who is medical director of infection prevention and control at Lurie. He leads the hospital’s COVID-19 response.

At Lurie, the number of COVID-19 cases has shot up 15 times higher than it was a month ago, and hospitalizations are eight to 10 times higher in the same time period, he said.

The bulk of patients who are admitted to the hospital are unvaccinated, Kociolek said.

In Chicago just before the new year, only 23%of children ages 5 to 11 were fully vaccinated against COVID-19, and around 62% of kids and teens ages 12 to 17, according to the Chicago Department of Public Health.

“We’re in the midst of a COVID storm. But that storm can be managed with all of the tools we have in place to keep us safe and to lower the risk of harm as much as possible,” Kociolek said. “The risk is never going to be zero.”

Kristen Schorsch covers public health and Cook County on WBEZ’s government and politics desk. Follow her @kschorsch.