What we know about kids and the delta variant, according to experts

Kali Cook was 4 when she died after contracting Covid-19 last week in Galveston County, Texas, becoming the youngest resident of the county to die from the disease.

“She was so funny and sassy,” her mother, Karra Harwood, told The Galveston County Daily News of the little girl who liked playing with frogs and worms. “She was just so pretty and full of life.”

According to her family, Kali had no previously diagnosed health conditions and was found to be in good health by a doctor recently, Dr. Philip Keiser, the Galveston County local health authority, told NBC News. She began developing respiratory symptoms after other family members became sick with Covid and the next morning she was found dead. An autopsy is being conducted.

Keiser said Kali’s death was “really shocking,” but it should not have been, given that 40 percent of the county’s cases are people under 20 and the single largest demographic is children under 10. 

“This has our community all shaken up. How could this happen? Why could this happen?” he said. “But in some ways again when you step back and you look and see how delta can spread very rapidly and kids now are one of the largest unvaccinated groups in the country, it shouldn’t be surprising to us, even though it was quite shocking.”

As of Sept. 9, nearly 5.3 million children had been diagnosed with Covid-19, representing 15.5 percent of all cases, according to the American Academy of Pediatrics. More than 243,000 cases were reported from Sept. 2 to Sept 9., the second-highest number of child cases in a week since the beginning of the pandemic, representing nearly 29 percent of the weekly reported cases, according to AAP. The highest number of cases was just one week prior, with 251,781 new cases. The AAP reported that after declining in early summer, “child cases have increased exponentially, with nearly 500,000 cases in the past 2 weeks.”

Despite the explosion in cases, the Centers for Disease Control and Prevention and the pediatric specialists and clinical investigators studying the disease still do not have evidence that delta causes more severe infections in children and adolescents.

But experts are examining “red flags that could indicate greater disease severity in specific segments of the pediatric population,” said Dr. Jim Versalovic, the interim pediatrician in chief at Texas Children’s Hospital.

“For example, we are seeing Covid pneumonia and acute respiratory distress in infants and young children,” Versalovic said, adding that some cases were due to respiratory syncytial virus (RSV)-Covid co-infections with a greater hospitalization rate. 

“So, it can be difficult to understand whether we have more severe disease due to delta or co-infections,” he said.

A definitive answer could still be months away, Versalovic said, though he’s hopeful there will be “more clarity about this topic during calendar year 2021.”

“We need more time to evaluate the data across regions, age groups, different underlying medical conditions, and longer-term outcomes,” he said. 

“These questions can be challenging, and note that this delta surge is only 2 months old,” he said. “We can confidently state that the biggest impact of delta on children is simply greater case numbers or the much larger number of children with Covid.” 

An average 344 new Covid patients ages 17 and under were admitted to hospitals from the week of Sept. 7 to Sept. 13, down slightly from a recent peak of 371 a day from Aug. 29 through Sept. 4, according to data available from the CDC. More than 57,760 children have been admitted to hospitals since August 1, according to the data.

And at least 439 children have died from Covid, according to the latest CDC data, although serious complications in kids remain rare. 

Dr. Sean O’Leary, vice chair of the American Academy of Pediatrics’ committee on infectious diseases, said while the question of whether the virus is more severe for children is important, it is “not as important as how many children, frankly, right now are getting infected and getting hospitalized.”

“We still don’t really have that question answered for adult disease, where there are at least far more hospitalizations than there are in kids, so I think it’s going to be a hard question to answer.”

This month, the CDC found in two studies that children’s hospitalizations surged “nearly five-fold during late June–mid-August 2021,” according to one study. That study also found hospitalization rates were “10 times higher among unvaccinated than among fully vaccinated adolescents.”

The studies did not find evidence that the delta variant appeared to cause more severe illness in kids, but the sheer number of children exposed to it was driving an increase in kids hospitalized with Covid.

Whether or not delta itself is more severe, doctors say they are noting more instances of children falling severely ill as the pandemic has progressed and the delta variant has become predominant.

Dr. Inci Yildirim, a pediatric infectious disease specialist with Yale Medicine, said it was very uncommon earlier in the pandemic to see “a teenager who was intubated for days in the ICU. But now, since more children are being infected, more children are being hospitalized.”

“This is the first time I’ve seen this many pediatric patients with Covid-19 in the hospital,” she said. “This was not the case 8-10 months ago.”

Yildirim said Covid is a milder disease in children than in adults, “but it is not a mild disease in childhood at all, when you have hundreds of children dying.”

Dr. Claudette Poole, a pediatric infectious disease doctor with Children’s of Alabama hospital, said the hospital has been testing all children admitted since spring of last year for Covid. 

When looking at how the virus was manifesting in children in August 2020, around 44 percent were completely asymptomatic, she said. Now, only 10 percent of the kids are asymptomatic, she said.

Poole said this appeared to show delta could be more likely to cause actual symptoms in children than prior variants.

But she also said a lot is different now this time of year compared to the same time last year. 

“There was a lot more remote learning, we were in much stricter sort of mitigation measures a year ago, than we are now,” she said. “So, it’s a combination of less mitigation measures, and definitely a more transmissible virus compared to what we were dealing with last year, and it appears that it is more likely to cause symptomatic illness than the prior variant, so it’s like a triple whammy if you would.”

Poole said it was important for people to know Covid can cause severe disease in children, even if it is more rare than in adults. 

“We’re certainly seeing children ending up in the ICU in numbers that we did not experience earlier in the pandemic,” she said. “And when I say ICU level of care, I mean they are getting desperately, desperately ill.”

“It’s just alarming to us that this many kids are getting sick and requiring hospital level care,” she said.