The latest coronavirus surge sweeping the United States, much of it driven by the highly contagious omicron variant, has produced a worrisome spike in hospitalizations among children, not to mention heightened anxiety among parents nationwide.
Several states have reported increases of about 50% in pediatric admissions for COVID-19 in December. New York City has experienced the most dramatic rise, with 68 children hospitalized last week, a fourfold jump from two weeks earlier.
But even as experts expressed concern about a marked jump in hospitalizations — an increase more than double that among adults — doctors and researchers said they were not seeing evidence that omicron was more threatening to children.
In fact, preliminary data suggests that compared with the delta variant, omicron appears to be causing milder illness in children, similar to early findings for adults.
"I think the important story to tell here is that severity is way down and the risk for significant severe disease seems to be lower," said Dr. David Rubin, a researcher at Children's Hospital of Philadelphia.
Instead, much of the rise in pediatric admissions results from the sheer number of children who are becoming infected with delta and the more contagious omicron variant, he and other experts said, as well as low vaccination rates among children older than 5.
Younger children do not yet qualify for vaccination, and only those age 16 and older qualify for booster shots, which offer the most effective shield against infection and hospitalization.
The upshot is that children overall are somewhat less protected from the virus than adults. In the week ending Dec. 23, about 199,000 childhood cases were reported nationally, a 50% increase compared with the beginning of December, according to the American Academy of Pediatrics.
Roughly 1 in 10 American children has tested positive for the virus since the beginning of the pandemic, according to the academy.
Infected children remain far less likely to become ill compared with adults. But across the country last week, an average of 1,200 children each day have been hospitalized with the coronavirus, up from 800 at the end of November, according to the Department of Health and Human Services. (Some of those children arrived at the hospital with other medical issues.)
Those numbers are well below the peaks reached in September, although experts also fear a wave of pediatric hospitalizations in the coming weeks, fueled by omicron's spread, holiday gatherings and a return to classrooms after Jan. 1.
"We're just holding our breath and bracing for a tsunami of impact," said Dr. Patricia Manning, chief of staff at Cincinnati Children's Hospital.
Hospital leaders and critical care doctors said that nearly all the children hospitalized with COVID-19 had one thing in common: They were unvaccinated or undervaccinated.
"What we're seeing in our ICU makes it crystal clear that vaccination is the single most important thing you can do to protect your kid from getting sick with this virus," said Dr. James Schneider, chief of pediatric critical care at Cohen's Children's Medical Center in New York, which serves nearly two dozen hospitals in the Northwell Health system.
In recent days, Schneider said, five to eight children with COVID-19 were in the intensive care unit, compared with none or one in November.
It remains unclear to what degree the omicron variant is responsible for rising hospitalizations. The Centers for Disease Control and Prevention on Tuesday significantly lowered its estimates for omicron's prevalence, to 59% from 73% of all COVID-19 cases in the week ending Dec. 18.
More recent data suggests that omicron is far more prevalent in some states, especially in the Northeast. In Connecticut, for example, the variant is responsible for more than 80% of new cases. That figure is 90% in New York.
Also complicating the picture: Alarming hospitalization figures can be misleading because they sometimes include all children who have tested positive for the coronavirus upon admission.
Some hospitals around the country have reported positivity rates as high as 20% among children. But the vast majority were asymptomatic and arrived at the hospital with other health problems, officials say.
Rubin said the real-time data he had been analyzing, as a lead investigator with the PolicyLab COVID-19 forecasting model, indicated that in southwest Pennsylvania, where omicron dominates, the proportion of pediatric admissions requiring intensive care services had dropped by half since early fall and has continued to decrease in the past month.
And the rate of pediatric COVID-19 admissions in much of the country was still below the peak of what is typically seen with the seasonal flu, he said.
Some of the recent increase, he said, was most likely tied to delays in seeking medical care for children as infections soared again, combined with the spread of wintertime viruses that can complicate the health of medically fragile children and lead to hospitalization.
"While we are definitely seeing more transmission among children, both vaccinated and unvaccinated, I think we have to be very careful to avoid sending the message that omicron poses an unusual risk to kids," Rubin said.
Even if children are at low risk for becoming seriously ill, medical experts caution that the coronavirus can on rare occasions lead to grave outcomes: 790 Americans younger than 18 have died since the pandemic began.
And despite guarded optimism that the omicron variant will be even less dangerous to children than its predecessors, experts acknowledge that it is still too early to know for sure.
"There are just so many caveats," said Dr. Rick Malley, a pediatrician at Boston Children's Hospital, which has not yet seen an appreciable rise in admissions for COVID-19.
He said he was awaiting more telling data on the length of hospitalizations and on whether young patients are needing oxygen or intubation. "It's premature to predict what's going to happen with omicron, because this virus has repeatedly surprised us," Malley said.
But one thing is beyond dispute: omicron's uncanny ability to spread among human hosts, even those who have been fully vaccinated. At Texas Children's Hospital in Houston, nearly one-quarter of all children admitted in recent days have been testing positive, up from 5% during the height of the delta surge this past summer. Omicron accounts for more than 90% of those infections, according to Dr. James Versalovic, the hospital's chief pathologist.
But so far, he said, the crush of infections has not led to a big jump in the number of children who need to be hospitalized for COVID-19 — about 50 in recent days, down from a peak of 65 a few months ago.
Although weary from having weathered three previous waves, Versalovic was somewhat hopeful that advancements in the treatment of seriously ill patients and an uptick in vaccinations would protect most children from dire outcomes.
"Sure I'm worried, but I'm also optimistic that we're going to be able to blunt the impact of omicron," he said.
This article originally appeared in The New York Times.