But rates of Covid-19 cases and hospitalizations among children have hit record highs in recent weeks. With case rates as high as they are, even small risks of serious outcomes can land large numbers of children in hospital, experts say.
“When you have such a large number of infected individuals, even a low probability of a serious event – which is usually the case with children; they generally tolerate the virus much better than adults – it stands to reason that you will to see more children with rare and potentially serious consequences of infection,” said Dr. Richard Malley, infectious disease specialist at Boston Children’s Hospital.
“In many ways, both statements could be true. Omicron might be milder in children than previous variants, but we could still see many more severe Covid cases, even with a milder virus.”
For the new study, researchers analyzed the electronic health records of about 80,000 children under age 5 who were first infected with Covid-19 in the United States. This age group is not yet eligible to be vaccinated, and the researchers note that low rates of previous Covid-19 infection also limit their pre-existing immunity.
The study found an approximately 70% reduction in hospitalizations, ICU admissions and mechanical ventilation in children infected with Omicron compared to those infected with Delta. They also found a 29% reduction in emergency room visits. Data on deaths were not included, as there were so few.
Overall, about 1% of children infected with Omicron were hospitalized, compared to about 3% of children with Delta, according to the study.
“Despite this encouraging result, further studies are needed to monitor the longer-term acute consequences of Omicron infection, the propensity for the development of ‘long COVID’, the speed of spread, the potential for mutation, and how prior infections alter clinical responses,” the researchers wrote.
In the last week of December, there were about 10 hospitalizations for Covid-19 per 100,000 children under age 5, more than at any other time during the pandemic, according to data from the Centers for Disease Control and Prevention of the United States. And while the results are promising at a broad population level, the experience for families with children who end up in hospital is no less dire.
“Imagine you’re the parent. Imagine you’re the child. I mean, these things are extremely stressful,” Malley said. “The child who is admitted does not know that his hospitalization will be short or less severe. The parent does not know either.”
And in addition to not being eligible for vaccination, children face a few additional unique risk factors that could increase transmission – and the potential risks of a serious outcome.
“I don’t think the virus really acts differently in children than it does in adults. But I think children are different from adults,” said Dr. Karen Ravin, chief of infectious diseases at Nemours Children’s Hospital in Delaware.
“Kids are kids, and so they’re more likely to bond with people when they talk to them. When they play, they come together. They tend to touch everything and bond with everyone, so I think that for any type of respiratory virus, that clearly puts them at a bit more risk than adults who are perhaps better able to keep our distance.”
And with schools and preschools now back in session, that transmission is more likely, which could explain why children began to account for a larger share of cases and hospitalizations during the delta surge than previous waves as well. .
“It’s a different playing field,” Ravin said.
In addition to patients with Covid-19, hospitals are now caring for more children for whom care had been postponed or otherwise avoided.
“At the start of the pandemic, the hospital was quite empty. There weren’t many traumas, other acute injuries or medical issues. Unfortunately with the pandemic – and this is true for pediatric and adult patients – a lot of people have kind of postponed or waited to get medical care for different issues because of the fear of the pandemic,” Ravin said.
“Now we see the aftermath, where we have a lot of patients admitted at the moment for a lot of other acute medical conditions and a lot of children admitted with Covid on top of that. So there are just a lot of sick people at the hospital. “
All things considered, experts say, parents shouldn’t alter the prevention measures they’ve taken.
“There are things parents can do that they couldn’t do a year ago. One of them is to make sure everyone around a child who is eligible for vaccination or booster gets that vaccination or booster,” Malley said.
“Also, maintain the same kind of preference for outdoor activities versus indoor activities, and ensure that masks are worn whenever they are indoors. Those things, I think, should be re-emphasized.”
The new study has not been peer-reviewed or published in a professional journal. It included about 7,000 children infected at a time when the Omicron variant was predominant and about 63,000 children infected when Delta was predominant. The virus samples were not sequenced for each child, but rather were assumed based on broader sequencing data from the time. Omicron accounted for approximately 92% of samples in the two weeks ending January 6, while Delta accounted for 99% of samples between September and mid-November.
The study also found that both variants disproportionately infect black children, but especially the Omicron variant. More than a quarter (26%) of children infected with Omicron were black, but less than 15% of children who had contact with the healthcare system during the same period were black.