Characteristics and Clinical Outcomes of Children and Adolescents Aged <18 Years Hospitalized With COVID-19

Six Hospitals, United States, July-August 2021

Valentine Wanga, PhD; Megan E. Gerdes, MPH; Dallas S. Shi, MD, PhD; Rewa Choudhary, MD; Theresa M. Dulski, MD; Sophia Hsu, MSN, MPH; Osatohamwen I. Idubor, MD; Bryant J. Webber, MD; Arthur M. Wendel, MD; Nickolas T. Agathis, MD; Kristi Anderson, MD; Tricia Boyles, MHA; Sophia K. Chiu, MD; Eleanor S. Click, MD, PhD; Juliana Da Silva, MD; Hannah Dupont, MPH; Mary Evans, MD; Jeremy A.W. Gold, MD; Julia Haston, MD; Pamela Logan, MD; Susan A. Maloney, MD; Marisol Martinez, PharmD; Pavithra Natarajan, BMBS; Kevin B. Spicer, MD, PhD; Mark Swancutt, MD; Valerie A. Stevens; Jessica Brown, PhD; Gyan Chandra, MBA; Megan Light, MPH; Frederick E. Barr, MD; Jessica Snowden, MD; Larry K. Kociolek, MD; Matthew McHugh, MPH; David Wessel, MD; Joelle N. Simpson, MD; Kathleen C. Gorman, MSN; Kristen A. Breslin, MD; Roberta L. DeBiasi, MD; Aaron Thompson, MD; Mark W. Kline, MD; Julie A. Bloom, MD; Ila R. Singh, MD, PhD; Michael Dowlin; Mark Wietecha, MS, MBA; Beth Schweitzer, MS; Sapna Bamrah Morris, MD; Emily H. Koumans, MD; Jean Y. Ko, PhD; Anne A. Kimball, MD; David A. Siegel, MD


Morbidity and Mortality Weekly Report. 2021;70(5152):1766-177. 

In This Article


In this study of six U.S. hospitals during July–August, 2021, approximately three quarters of pediatric patients with COVID-19–related hospitalizations were hospitalized for COVID-19. The majority of those hospitalized for COVID-19 were Black or Hispanic and were aged <5 or 12–17 years. Approximately one third of patients aged <1 and 1–4 years had a viral coinfection, approximately one third of patients aged 5–11 years and approximately two thirds of patients aged 12–17 years had obesity. Less than 1% of vaccine-eligible patients were fully vaccinated against COVID-19.

Five of the six hospitals had policies to test all pediatric patients for SARS-CoV-2 upon admission during the study period, allowing for detection of incidental positive SARS-CoV-2 test results. However, the proportion of such patients was smaller in this study compared with that in a previous report.[1] Patients aged 0–4 and 12–17 years accounted for 79% of COVID-19–related hospitalizations in this study, which is consistent with data from other hospitals and communities.[2] Among hospitalized children aged <5 years, most were aged <1 year, which might reflect clinical practice differences, because infants might be more likely to be hospitalized with milder disease than older children.[3] Most patients were Black or Hispanic in this study; an earlier study demonstrated higher hospitalization rates among Black or Hispanic children compared with White children.[1]

Approximately two thirds of patients hospitalized for COVID-19, including 83% and 88% of patients aged 5–11 and 12–17 years, respectively, had one or more underlying medical conditions. Approximately two thirds of patients hospitalized for COVID-19 aged 12–17 years had obesity. Compared with patients without obesity, those with obesity required higher levels and longer duration of care. These findings are consistent with previous reports[4] and highlight the importance of obesity and other medical conditions as risk factors for severe COVID-19 in children and adolescents.

The proportions of patients admitted to ICU and who required IMV are similar to those in prior reports, which predominantly included hospitalized pediatric COVID-19 patients before Delta variant predominance.[2,5] Adolescents were more likely to require ICU admission and oxygen support compared with other age groups and required the longest median duration of IMV. The median duration of IMV overall (7 days) is consistent with previous reports.[6,7] Approximately one half of patients aged 1–4 years required oxygen support, which might be related to the high proportion with viral coinfection. This study occurred during July–August 2021, the first period during the COVID-19 pandemic with high circulation of RSV¶¶¶¶ and other respiratory viruses. Compared with prior studies,[2,5] this study found a high proportion of patients had high-flow nasal cannula as the highest level of respiratory support (37%), which might reflect a change in practice to avoid intubation or the high proportion of viral coinfections, including RSV.

On November 2, 2021, CDC recommended COVID-19 vaccinations for children aged 5–11 years.[8] As of July 31, 2021, 29% of U.S. persons aged 12–17 years were fully vaccinated against COVID-19.***** In this study, only 0.4% of vaccine-eligible adolescents hospitalized for COVID-19 were fully vaccinated. Hospitalization rates have been shown to be 10 times higher among unvaccinated adolescents compared with fully vaccinated adolescents.[2] Similarly, this study demonstrates that unvaccinated children hospitalized for COVID-19 could experience severe disease and reinforces the importance of vaccination of all eligible children to provide individual protection and to protect those who are not yet eligible to be vaccinated.

The findings in this report are subject to at least five limitations. First, the data came from only six hospitals, five of which are in the southern U.S. region. The proportion of adolescents with obesity in the southern United States is higher than in other regions,††††† which might explain the high rates of obesity described in this report. Therefore, findings might not be generalizable to other areas. Second, findings might reflect differences in practices by hospitals or changes in practice over time and might not reflect differences in severity of COVID-19 related to the Delta variant. Third, incomplete or missing data in medical records might lead to underreporting and underestimation of details such as COVID-19 vaccination frequencies. Fourth, at the time of hospitalization, persons aged 12–15 years had only been vaccine-eligible for 2–3 months,[9] possibly contributing to the low vaccination rates observed. Finally, hospitals identified patients for review based on positive polymerase chain reaction and antigen SARS-CoV-2 test results and hospitalization during the study period. Therefore, proportions of patients with MIS-C are likely underestimated.

Among pediatric patients with COVID-19–related hospitalizations, many had severe illness and viral coinfections, and few vaccine-eligible patients hospitalized for COVID-19 were vaccinated. These data highlight the importance of COVID-19 vaccination for those aged ≥5 years and other prevention strategies to protect children and adolescents from COVID-19, particularly those with obesity and other underlying health conditions. Further research and surveillance for viral coinfections with SARS-CoV-2 in pediatric patients can inform public health and capacity planning.[10]