Last reviewed: September 10, 2021
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Overview
Children and young adolescents experience COVID-19 disease and manifestations differently than adults. This page includes clinical guidance and notable research findings on COVID-19 manifestations and treatment in pediatric populations. For guidance specific to school settings, refer to our Back-to-School Safety page.
Epidemiology
Although most COVID-19 morbidity and mortality occurs in older adults with comorbidities, SARS-CoV-2 infection appears common in children and vastly underreported given milder presentations and variable age-stratified reporting.
Between February 2020 and March 2021, CDC estimates 27 million infections occurred in U.S. children under 18 years of age — ten times higher than the cumulative reported case incidence. Approximately 20% of all U.S. COVID-19 cases diagnosed in spring and summer 2021 have been in children, a percentage similar to their proportion of the overall population, according to a report by the Children’s Hospital Association and the American Academy of Pediatrics. The report also notes that after the early summer of 2021 saw a decline in U.S. pediatric case rates, there was a 20-fold rise in pediatric cases between June and August, reaching over 180,000 new cases per week. AAP collects regularly updated U.S. data on COVID-19 incidence in children.
Transmission
Experts originally hypothesized that children did not drive COVID-19 transmission; instead, studies indicated that 90% of pediatric infections were due to contact with an infected adult and unlikely to result in clinically significant secondary or tertiary transmission (Posfay-Barbe, August 2020; Zhu, December 2020).
However, more recent data indicate that children can contribute to substantial household transmission, serving as index cases that lead to potentially severe disease in adult contacts (Chu, September 2021). Although pediatric community case rates have generally been highest in adolescents (Leidman, January 2021), recent studies indicate that the youngest children may be equally or more likely to contribute to secondary transmission within households (Paul, August 2021). Multiple CDC Morbidity and Mortality Weekly Report case series indicate high attack rates among children during outbreaks in congregate settings, including an overall attack rate above 40% during a summer camp outbreak (Szablewksi, August 2020), and evidence of efficient classroom spread from an unmasked teacher to multiple students (Lan-Hime, September 2021).
Outcomes
COVID-19 mortality remains very low in children (<0.04% case fatality ratio), yet 2% of cases may result in hospitalization and 20-30% of hospitalized children may require intensive care unit admission (COVID-NET; Götzinger, September 2020; Kim, August 2020; Moreira, January 2021). As of August 2021, CDC reports over 450 deaths in U.S. children 18 years and younger with a diagnosis of COVID-19.
Severe illness appears more common in children under one year of age and among those with one or more significant comorbidities such as diabetes, obesity, immunocompromise or chronic pulmonary and cardiac disease (COVID-NET; Graff, April 2021; Dong, June 2020; Kompaniyets, June 2021).
Multisystem Inflammatory Syndrome in Children
Multisystem inflammatory syndrome in children (MIS-C) is a rare, Kawaski-disease-like multi-organ shock syndrome that has affected more than 4,000 U.S. children showing evidence of SARS-CoV-2 infection and resulted in over 40 reported deaths, according to CDC data.
In contrast to severe COVID-19 without MIS-C, this febrile syndrome predominately affects school-aged children (ages 5-13), with prominent cardiovascular involvement including myocarditis and coronary aneurysm requiring vasopressor support. Mucocutaneous and gastrointestinal manifestations are also more common than in other severe COVID-19 illness, in addition to very high levels of inflammation (e.g., elevated C-reactive protein, absolute neutrophil counts) (Feldstein, February 2021).
High-dose intravenous immune globulin has emerged as a mainstay of treatment (AAP Interim Guidance), with adjunctive corticosteroids possibly associated with improved treatment response in observational analyses (Ouldali, February 2021).
Nearly two-thirds of U.S. MIS-C cases have occurred among Black and Latinx children (Payne, June 2021); it is not clear if this ethnic distribution reflects overall disparities in COVID-19 burden or may involve biological factors.
Disease Management and Prevention
Most clinical trials and retrospective studies of COVID-19 management have not included pediatric patients; therefore, pharmacological management algorithms (apart from those for MIS-C) are largely based on expert opinion and/or mirror recommendations for adults (see NIH and AAP guidance). This includes use of emergency-use-authorized or approved medications such as remdesivir, monoclonal antibodies and corticosteroids to treat acute disease.
Vaccination has emerged as a key intervention to reduce and prevent disease in children, with FDA approval of the Pfizer-BioNTech vaccine for children as young as 12 years. As of August 2021, 12.7 million U.S. children ages 12-18 have received at least one COVID-19 vaccine dose, with wide regional variability (for example, Vermont reported more than 70% of adolescents had received a first dose, compared to 20% in Alabama) (Murthy, September 2021). Ongoing studies are actively evaluating the safety and effectiveness of COVID-19 vaccines for younger children.
Post-Acute COVID Syndrome in Children
The incidence of post-acute symptoms in children who have had COVID-19, (i.e., persistent symptoms lasting >1-3 months following onset of COVID-19 symptoms or diagnosis) is an area of active investigation. Interim AAP guidance addresses follow-up care of infants, children and adolescents after a SARS-CoV-2 infection.