While COVID-19 has taken the lives of many children and caused serious illness for many more, it is generally agreed that the virus is much less likely to inflict severe damage in the young.
But new data from the U.S. Centers for Disease Control and Prevention has revealed a concerning trend: The rate of COVID-19-linked hospitalizations among children younger than 5 grew substantially last week, while the same rate for children between the ages of 5 and 17 remained relatively stable.
The latest numbers have sparked concerns that the youngest members of society may be more vulnerable to the Omicron variant than their older peers. The affected children, ages 4 and under, are in the age group not yet eligible for a coronavirus vaccine.
While scientists' knowledge of Omicron is still evolving, experts say the upsurge in pediatric hospitalizations does not indicate that Omicron is more dangerous to young children than other variants were.
Overall, the CDC report revealed that the record number of infections in recent weeks has triggered a hospitalization surge.
But among children, the under-5 age group experienced the most notable increase.
During the week of Dec. 26 through Jan. 1, the CDC's data shows that more than 5 in every 100,000 hospitalized children ages 0 to 4 were infected with COVID-19, which is nearly double the rate reported in early December before the Omicron variant began to take over. For older children, ages 5 to 17, the rate was significantly lower, at 1.4 per 100,000, in keeping with past weeks.
Throughout the pandemic, children have only made up a small subset of hospital admissions, and the hospitalization rates for all other age groups remain much higher than those seen in children.
Still, the surge in pediatric hospital admissions is worrying. But according to Dr. Richard Malley, a pediatric infectious disease specialist at Boston Children's Hospital, the numbers are not particularly surprising. Malley said the increase in hospitalizations is a predictable consequence of the unprecedented case counts.
"If the risk of catching the virus has increased, even if children are generally less susceptible to severe consequences from that infection, that small number of children who would normally have been hospitalized due to COVID increases," he explained.
To add to the uncertainty, CDC Director Dr. Rochelle Walensky has emphasized that hospitalization rates can be distorted by "incidental" cases. The CDC's data, she said, includes children who tested positive for COVID-19 but may be in the hospital for other reasons. "Many children are hospitalized with COVID as opposed to because of COVID," Walensky said in December.
Some states are sorting hospital numbers
"Hospitals have gotten very good at screening everybody who gets admitted to the hospital," Malley explained. "So now, people are being hospitalized for one reason, and then a positive test comes back and gets reported as a child hospitalized with COVID, even if the reason for the hospitalization could be, for example, a broken bone."
Some states, including Massachusetts and New York, are correcting this problem by instituting a system that differentiates between incidental cases and true hospitalizations due to COVID. But at this point, it is unclear what portion of hospitalizations are incidental.
Another factor to consider is that young children who seek treatment at a hospital are not always severely ill.
Dr. Santhosh Nadipuram, a pediatric infectious disease specialist at Cedars-Sinai Maxine Dunitz Children's Health Center in Los Angeles, explained that hospitals will accept young children even if their symptoms are not particularly alarming. Most often, these kids are in need of supportive care, such as oxygen, hydration and monitoring by a team of professionals while they fight off the infection.
When severe infections do occur in children, they tend to strike those with underlying conditions, including obesity, prediabetes, heart problems and asthma. According to Nadipuram, symptoms that should prompt parents to bring their young children to the hospital include difficulty breathing, fast breathing, dehydration and extreme irritability or fatigue.
Unfortunately, "the symptoms are actually very generic, and they hold true for other respiratory viral infections," he said.
For the most part, young patients seeking care for COVID-19 at hospitals are not seriously ill, according to Malley.
"While not minimizing how scary and worrisome it might be for a child to be hospitalized with COVID, in general, those children are not severely affected. Most of them are not critically ill like the adults that we see with COVID-19," he said.
However, doctors are on the lookout for Multisystem Inflammatory Syndrome (MIS-C), a rare condition that some children develop a few weeks after being infected with COVID-19.
Dr. Allison Messina, a pediatric infectious disease specialist at Johns Hopkins All Children's Hospital in St. Petersburg, Fla., said a spike in MIS-C cases might pop up in the coming weeks.
"We haven't been seeing a ton of MIS-C yet, but I'm waiting to see what's going happen in the next month because we may see a rise," Messina said.
Omicron may be less likely to trigger long-term problems
But there is some hope that Omicron may be less likely to cause long-term or delayed effects, including MIS-C, than other COVID-19 variants.
At this early stage in the Omicron wave, experts are still learning about its unique mechanisms and how it may or may not impact patients differently. However, evidence is mounting that this particular breed of COVID-19 concentrates its attack on the nose and throat. Other variants, such as Delta, were typically more adept at moving down to the lower respiratory tract and wreaking havoc on the lungs.
With earlier COVID-19 variants, the timeline of a severe infection is often drawn out, and the problems usually begin once the virus reaches the lungs, Nadipuram explained.
"The severe symptoms in those first couple of waves were kind of delayed -- meaning that you caught COVID, and then you were intubated for a while, especially in those really high-risk folks who are 70 years old and over," he said. "Then there would be this inflammatory reaction, and they would crash, and those were the folks that we saw in our intensive care units."
Nadipuram said Omicron appears to operate on a tighter timeline. "Right now, this seems to be acting much more like a very acute disease, very short-term, where you catch it, and then 12 to 24 hours later, there are symptoms."
The signs that an Omicron infection is taking a turn for the worse tend to materialize more quickly and obviously. With Omicron, "patients kind of pick a lane," Nadipuram said. "If they're low-risk and they're doing OK, then they convalesce, meaning they get better. And if they're the high-risk patients, they get sick during that acute period of time."
From the available evidence and what he has observed at the hospital, Nadipuram believes that Omicron is less likely to surprise doctors with long-term effects and delayed reactions, including MIS-C.
"We're not worrying about these long-term after-effects that happened two, three, four weeks later where our patients used to get these horrible inflammatory diseases, including this other entity MIS-C that we worried about in kids," he said. "We're just not seeing it anywhere because this particular strain really seems to act in the here and now."
Still, only time will tell what to expect from the Omicron variant. Even if it proves to be less dangerous than prior strains, the sheer number of infections will result in a great deal of injury and loss, Malley said. "That's not the right message we want to send, that this virus is not as bad, and therefore it's OK if we drop some of our precautions," he added.
For now, kids under 5 will remain vulnerable, especially while waiting vaccine approval for this age group. A vaccine is unlikely to become available anytime soon because clinical trials are still in progress.
In the meantime, Walensky said the key to protecting those children who are too young for a COVID vaccine is to ensure everyone around them is vaccinated and boosted.
"Please, for our youngest children, those who are not yet eligible for vaccination, it's critically important that we surround them with people who are vaccinated to provide them protection," she pleaded during a Friday media briefing on the issue.
More information
The U.S. Centers for Disease Control and Prevention has more on COVID-19 in kids.
SOURCES: Richard Malley, MD, pediatric infectious diseases, Boston Children's Hospital, and professor, pediatrics, Harvard Medical School, Boston; Santhosh Nadipuram, MD, pediatric infectious diseases, Cedars-Sinai Maxine Dunitz Children's Health Center, Los Angeles; Allison Messina, MD, chief, pediatric infectious diseases, Johns Hopkins All Children's Hospital, St. Petersburg, Fla.; U.S. Centers for Disease Control and Prevention, COVID Data Tracker Weekly Review, Jan. 7, 2022
