Over the past two years, the pandemic has taken a toll on many Americans—and children in particular have experienced unique effects from Covid-19 and other pandemic stressors.

How children fare against Covid-19

According to the American Academy of Pediatrics (AAP), over 12.5 million children have tested positive for Covid-19 since the beginning of the pandemic, making up 19% of all reported cases in the United States. Notably, over 4.6 million of these cases were reported since the beginning of January when the omicron variant became dominant.

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However, despite the significant rise in cases in recent months, children remain largely protected from severe Covid-19 outcomes. Cumulative data from 25 states and New York City show that only 0.1% to 1.5% of pediatric Covid-19 cases resulted in hospitalization. Similarly, data from 46 states, New York City, Puerto Rico, and Guam report that children made up between 0% and 0.25% of all Covid-19 deaths, with three states reporting zero pediatric Covid-19 deaths.

According to several health experts, children's lower risk of severe illness and death from Covid-19 may be due to differences in their immune systems, as some research suggests children may have a more robust innate immune systems than adults.

For example, a study published in JCI Insight found that more genes involved in innate immunity were activated in children and that children had more cytokines associated with innate immunity than adults.

At the same time, children typically lack strong pre-existing antibody responses against SARS-CoV-2 because they've had less exposure to other coronaviruses, such as those that cause common colds, than adults.

According to Amy Chung, a researcher at the Peter Doherty Institute for Infection and Immunity in Australia, this lack of immune memory may be advantageous against SARS-CoV-2, since the immune system will attack the essential parts of the virus first. In comparison, adults' immune systems will typically target parts that they recognize from other coronaviruses, which "don't seem to be as important to stopping infection," Chung said.

However, despite children's more robust immunity against the coronavirus, many health experts still emphasize the importance of vaccines to protect vulnerable children and control infections. Currently, vaccination rates for children under 18 lag significantly behind adult rates, with only around 40% of eligible children fully vaccinated.

"The innate barrier is not 100% protective," said Betsy Harold, a pediatric infectious disease physician at the Children's Hospital at Montefiore, adding that parents are "taking a gamble" when they choose not to vaccinate their children.

The pandemic's indirect effects on children's health

Aside from Covid-19, the pandemic has had indirect effects on children's health, including increased stress and new mental health concerns.

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According to a CDC study published last week, overall ED visits by children decreased over the course of the pandemic (2020, 2021, 2022), but the number and percentages of visits for chronic illnesses, some injuries (e.g., guns, self-harm, drugs), and mental health concerns rose during that same time period.

These findings suggest a need for vigilance on the pandemic's indirect effects on children's and adolescent's health, the study's authors wrote, particularly for problems from delayed care and mental health concerns.

"Prevention programs that improve children and adolescents' physical and mental health are critical during and after emergencies," the researchers wrote. "Reducing Covid-19 infection through vaccination and other nonpharmaceutical prevent strategies can further protect pediatric health."

Separately, a second CDC study compared pediatric ED visits for mental health conditions during the pandemic and before the pandemic in 2019. The study found that while mental health-related ED visits by boys ages 12-17 declined, there was a significant increase in ED visits by girls of the same age.

In particular, the proportion of ED visits made by girls doubled for eating disorders and approximately tripled for tic disorders during the pandemic compared with 2019. ED visits made by girls for depression and obsessive-compulsive disorder (OCD) rose in 2021, and for anxiety, trauma and stressor-related disorders, and OCD in January 2022.

According to the study's authors, risk factors related to the Covid-19 pandemic, such as "lack of structure in daily routine, emotional distress, and changes in food availability," could have triggered an increase in eating disorders, while pandemic stress and exposure to tic-like behavior on social media platforms could have led to an increase in tic disorders.

However, the authors wrote that "the highly complex nature of individual experiences makes it difficult to identify a single reason for changes in [mental health conditions] during the pandemic." They also noted that while prolonged time at home could have helped some adolescents identify and get support for their mental health needs, others may have experienced increased adversities and stressors. (Toy, Wall Street Journal, 2/21; AAP Children and Covid-19: State Level Data Report, accessed 2/23; Folmar, The Hill, 2/22; CIDRAP News, 2/21)