At Texas Children's Hospital, four-month-old Graysen Perry has COVID-19 and is struggling to breathe.

His mom, Gayvielle Goff, is struggling to talk.

"It's just really scary," Goff said, trying to suppress tears.

At the same Houston hospital, 17-year-old Halie Mulanax is fighting COVID-19 on a ventilator. She's never seen her three-week-old baby because she's been in a medically induced coma for almost a month.

Across the country, hospitals are grappling with an unprecedented surge of children with COVID-19 -- fueled by holiday gatherings and the highly contagious Delta and Omicron variants.

Last week, an average of 574 children with COVID-19 were admitted to hospitals every day -- a pandemic record, according to data from the U.S. Centers for Disease Control and Prevention.

And one doctor worries "we could see more children hospitalized over a very short period of time."

A TEEN IN A COMA MISSED HER BABY'S BIRTH

Halie just spent her 17th birthday in a medically induced coma.

She has no idea her daughter, Xylah, had to be delivered 10 weeks early.

The family's COVID-19 ordeal has been "gutwrenching," Halie's mother Amy Woodruff said.

"Our COVID journey began ... November 29. Me and my daughter both tested positive for COVID," Woodruff said.

While Woodruff fared well with her illness, her teen daughter not.

Halie was hospitalized in Amarillo and had to be put on a ventilator.

At 29 weeks into her pregnancy, "she couldn't breathe," Woodruff said. "Her oxygen level was very low -- not enough to support the baby."

So while in a medically induced coma, Halie had a Caesarian section and gave birth to Xylah on December 9.

She weighed 3 pounds and 6 ounces. Miraculously, her grandmother said, the baby did not have COVID-19.

Woodruff said she has no idea how she will break the news that Halie missed her daughter's birth and first several weeks of life.

"I'm a mom. I couldn't imagine. And that's my little girl being away from our little girl," Woodruff said. "My heart bleeds for her."

While Xylah stayed at an Amarillo hospital, her mother had to be transported 900 miles away to Texas Children's in Houston.

"Mom was in such bad shape, they couldn't do all the treatments that mama needed while the baby was still there" in Amarillo, Woodruff said.

Woodruff said Halie was not vaccinated against COVID-19 -- largely because she was concerned about how the vaccine might affect her baby.

But now, Woodruff said she'd encourage her loved ones to get vaccinated.

"Anybody I love, I would like for them to," she said.

'I DIDN'T EXPECT COVID'

Gayvielle Goff never imagined any of her children -- a five-year-old, a three-year-old and a four-month old -- could get this sick with COVID-19.

"They hardly even catch a cold," Goff said. "Some people may find that hard to believe. But my babies really don't get sick."

That changed drastically when four-month-old Graysen got COVID-19. Now he's hospitalized at Texas Children's, the largest pediatric hospital in the country. And Goff fears he will be put on a ventilator.

"I didn't expect COVID," the 24-year-old mother said.

"Since I was pregnant with him, I stayed in the house. I went to doctor's appointments. Maybe to the grocery store when I really needed to go to the grocery store. But other than that, I didn't go anywhere," she said.

But Goff said she is not vaccinated against COVID-19. She said she believes Graysen got sick with COVID-19 after a Christmas gathering.

Now, Goff said she's "actually thinking about" getting vaccinated.

'UNPRECEDENTED NUMBERS OF KIDS GETTING INFECTED'

In just two weeks, the number of kids hospitalized with COVID-19 at Texas Children's has quadrupled.

And the surge will likely get worse with the spread of the Omicron variant, said Dr. Peter Hotez, co-director of the Center for Vaccine Development at Texas Children's.

"This is by far the king of transmissible Covid viruses. And we're seeing unprecedented numbers of kids getting infected and going into children's hospitals," Hotez said.

On top of that, "we've just done a terrible job of vaccinating our kids across the country," he said.

Among the COVID-19 patients hospitalized at Texas Children's, "they're getting a lot of respiratory symptoms ... pneumonia, needing respiratory support to help them breathe better," said Dr. Melanie Kitagawa, the hospital's transitional ICU medical director.

While early studies suggest Omicron causes less severe disease than the Delta variant, Omicron is much more contagious.

And that means more children could be hospitalized, said Dr. Jim Versalovic, pathologist-in-chief at Texas Children's.

"The problem is that with so many children and adults infected, even if the percent hospitalization rate is lower, we could see more children hospitalized over a very short period of time," he said. "And that certainly puts a strain on our health care resources."