Though children won't likely get seriously ill from COVID-19, the fact is that there are some kids who may get very sick. 

Since a novel coronavirus was first identified in China in December 2019, researchers have been collecting and analyzing as much data as possible to work out how the virus behaves in children, as well as its impact by age and sex. 

A preliminary analysis of confirmed cases in the US suggests that, unlike adults, children's disease is generally less severe, but like their adult counterparts, males appear to be more susceptible than females.

Using data collected through April 2, researchers at the Centers for Disease Control and Prevention (CDC) identified a total of 2,572 COVID-19 cases in children under age 18. Among 2,490 pediatric cases for which sex was known, 57% were male. "Reasons for any potential difference in COVID-19 incidence or severity between males and females are unknown," say researchers in an analysis released April 6 in Morbidity and Mortality Weekly Report (MMWR). They say the predominance of males across all pediatric age groups suggests that biological factors may play a role in any susceptibility by sex.

The analysis provides a snapshot of symptoms and severity of illness among US children with COVID-19. Of 80 pediatric COVID-19 cases known to have at least one an underlying condition, the most common were chronic lung conditions, including asthma; heart disease; and immunosuppression. Among 291 pediatric cases with data on signs and symptoms, the most common were fever, cough, and shortness of breath; however, such symptoms were less frequently reported in kids compared with adults.

Researchers also estimated (based on 745 pediatric cases with data on hospitalizations) that relatively few kids with COVID-19—5.6% to 20%—land in the hospital. That compares with 10% to 33% of adults. Intensive-care unit admissions were also less common among children than adults—a finding the authors say is consistent with other studies showing that kids' illness is usually milder. Severe outcomes, including three pediatric deaths, have been reported, according to MMWR, but these cases are being reviewed to confirm cause of death.

Among all 2,572 pediatric COVID-19 cases, nearly a third occurred in children ages 15 to 17, researchers reported. However, the study also found that 59 of 147 pediatric hospitalizations (including five of 15 pediatric ICU admissions) were among the youngest of the young—those less than one year of age. (Again, this is preliminary data. The trouble is that most reported US cases in infants had unknown hospitalization status.)

While it may be some relief to parents that children generally experience mild symptoms, the fact is that some kids may get very sick. On March 28, Illinois health officials reported the first death of an infant who tested positive for COVID-19, the first known US fatality of a child under the age of 1. The state health department said in a statement that an investigation into the child's cause of death is underway. 

Separately, a study published March 16 in Pediatrics looked at data from January 16 to February 8 on 2,143 children in China. It found that cases of COVID-19 in kids were generally less severe than those in adults, although infants had higher rates of severe illness than older children. Just under 11% of infants had severe or critical cases compared to 7% of children ages 1 to 5, 4% of those ages 6 to 10, 4% of those ages 11 to 15, and 3% of those age 16 and older.

Nobody really knows why younger kids may be more susceptible to infection than older children, but one theory is that infants and babies have not yet developed immunity to any (or many) of the common coronavirus strains that normally circulate. Few of us had heard of coronavirus before the start of 2020, but it’s nothing new, pediatrician Cara Natterson, MD, the author of Decoding Boys: New Science Behind the Subtle Art of Raising Sons, tells Health. “It’s a family of viruses that causes the common cold. But this strain that is spreading across the world is new.” 

It makes sense that babies would be the sickest from COVID-19 because they have very vulnerable immune systems, Rebecca C. Brightman, MD, assistant clinical professor of obstetrics, gynecology and reproductive medicine at The Icahn School of Medicine at Mount Sinai, tells Health. 

The same reasoning explains why older children aren’t typically getting ill from the coronavirus. Of the children studied in China, about 4% of them were asymptomatic (showed no symptoms at all), 51% had mild illness, and 39% had moderate illness. About 6%  had severe or critical illness, compared to 18.5% of adults. One child, a 14-year-old boy, died.

“Once infants become toddlers, they are exposed to many germs and viruses, which serves to strengthen their immune systems, including the common coronavirus strains,” Dr. Brightman explains. “This is why children and young adults probably do well with COVID-19. With age (i.e. people over 65), the immune system weakens and they too are at greater risk of developing severe symptoms and warranting hospitalization.” 

The CDC confirms that coronavirus symptoms are similar in children and adults, adding that vomiting and diarrhea have also been reported in kids. “It’s not known yet whether some children may be at higher risk for severe illness, for example, children with underlying medical conditions and special healthcare needs,” the website states. “There is much more to be learned about how the disease impacts children.” 

In fact, clinicians are puzzled by reports of a new mysterious new illness in children that they think may be related to COVID-19, although no one knows for sure. Symptoms of so-called pediatric multi-system inflammatory syndrome can include fever, abdominal pain, rash, or other signs of inflammation in the body. It can look similar to Kawasaki disease (a rare childhood illness that causes blood vessels to become inflamed).

If you think your child has COVID-19 (or is exhibiting signs of this new syndrome), the first thing you should do is call your doctor ASAP. But don’t walk into an ER or urgent care unless you’re told to do so by a healthcare professional. “Right now, we want to keep people away from ERs to minimize the flood of patients that need to be seen,” explains Dr. Natterson. “We also don’t want to expose non-coronavirus patients to ones with the virus. Save the care for patients who need it.”

Your doctor will advise you on how to treat your child’s symptoms and protect other family members. “Parents should quarantine the entire family if one child is ill,” Dr. Natterson says. “The very best way to protect other people from getting the virus is to limit exposure, so if there is someone in the house in a high risk group (with an underlying medical condition or who is elderly), you will want to figure out a system to keep that person separated from the one who is infected with COVID-19, and you’ll want to wipe down surfaces frequently and wash hands very regularly.” 

If anything, the Pediatrics study should remind everyone of the importance of social distancing,  Dr. Natterson adds. “Parents shouldn’t feel added anxiety because of these reports—stressing out won’t help, but social distancing will.” 

She says the best protection against infection is to keep your kids home as much as possible, don’t have other kids (or adults) over to visit, and don’t go into other peoples’ homes for now. And when kids do hang out in person, keep it outside with at least six feet of distance between them. 

More testing and research is needed to understand children’s role in spreading the virus in their communities. In the meantime, follow the guidelines and your doctor’s advice, and stay safe. 

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDCWHO, and their local public health department as resources.

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