While children have largely been spared from severe COVID-19 disease compared to adults and seniors, some have still suffered serious outcomes requiring medical intervention and hospitalization. Some also experience lingering complications such as Multisystem Inflammatory Syndrome in Children (MIS-C), a rare but serious condition that can affect the heart, blood vessels, and other organs. CITF-funded experts Dr. Jesse Papenburg (McGill University) and Dr. Rae Yeung (University of Toronto) have recently contributed to articles addressing gaps in our understanding of COVID-19 in children (including infants less than a year of age), those impacted by MIS-C, and those with other comorbid conditions.

By evaluating pediatric hospitalization and deaths from acute COVID-19 among Canadian children between March 2020 and May 2021, Dr. Yeung’s team compared the outcomes of 330 children hospitalized with acute COVID-19 and 208 hospitalized with MIS-C. Acute COVID-19 was associated with more pediatric hospitalization, more deaths and longer hospital ICU stays compared to MIS-C. While MIS-C led to more ICU admissions, rapid stabilization using immune modulation and blood pressure support resulted in shorter stays and no recorded deaths. Furthermore, MIS-C was generally in children aged 5 to 11, while hospitalization with acute COVID-19 was associated with those under one year of age. Chronic comorbidities were also a common factor for acute COVID-19 hospitalization (1).

Dr. Papenburg and a team led by Drs. Shaun Morris and Fatima Kakkar conducted a similar national prospective study of infants with SARS-CoV-2 between April 2020 and May 2021 using the Canadian Pediatric Surveillance Program (2). Of the 531 patients (in-patients and out-patients) seen at clinics and emergency departments with cases of microbiologically confirmed SARS-CoV-2 infections, 62% were not hospitalized and 37% were hospitalized. Among those hospitalized, 71% were admitted due to COVID-19 while 29% were admitted for other reasons, but were incidentally detected to have SARS-CoV-2. The most common symptoms among all those affected with SARS-CoV-2 were fever, cough, rhinitis, and poor appetite. Similar to the observations in Dr. Yeung’s study (1), infants with other comorbid conditions had higher odds of hospitalization compared to those who didn’t have any other conditions. Generally, infants under 1 month of age had higher odds of hospitalization compared to those aged 1-3 months.

Both studies suggest that younger age and comorbid conditions in infants were associated with COVID-19-related hospitalization.

Dr. Papenburg also collaborated with Dr. Joan Robinson and the Canadian Pediatric Investigators Collaborative Network on Infections in Canada (PICNIC) team to evaluate the impact of SARS-COV-2 on children who were technology dependent (TD) – meaning they require medical devices to compensate for the lack of vital body functions (3). End-stage chronic conditions had the highest association with hospitalization and death related to COVID-19. Overall, children with TD were found to suffer an increased risk of hospitalization with COVID-19. Yet, in the absence of end-stage conditions, these children usually survived SARS-CoV-2 infection and were shortly discharged from the hospital.

Collectively, these studies have further elaborated the risk factors associated with severe outcomes of COVID-19 in young children and infants. While not exhaustive, these cohorts indicated that children readily recover from SARS-CoV-2 infections in the absence of comorbidities. Additionally, provided adequate medical treatment and care, those with MIS-C could expect a full recovery.

While the data collected in these studies were conducted prior to the Delta and Omicron waves, it was suggested that a lower incidence of MIS-C during this later phase of the pandemic may be associated with factors such as vaccination, increased physician recognition of MIS-C, and refinement of treatment strategies. This reflects a better understanding of the nuanced impacts of COVID-19 in various sub-groups of our population and more efficient and effective deployment of healthcare resources in treating patients.


  1. Farrar DS, Hepburn CM, Drouin O, Tal TE, Morin MP, Berard RA, et al. Demographic and Outcome Characteristics of Children Hospitalized with Acute COVID-19 versus Multisystem Inflammatory Syndrome in Children in Canada [Internet]. medRxiv; 2022 [cited 2022 Sep 21]. p. 2022.08.18.22278939. Available from: https://www.medrxiv.org/content/10.1101/2022.08.18.22278939v1
  2. Piché-Renaud PP, Panetta L, Farrar DS, Moore-Hepburn C, Drouin O, Papenburg J, et al. Clinical manifestations and disease severity of SARS-CoV-2 infection among infants in Canada. PLOS ONE. 2022 Aug 24;17(8):e0272648.
  3. Robinson J, Dewan T, Morris SK, Bitnun A, Gill P, Tal TE, et al. SARS-CoV-2 infection in technology-dependent children: a multicenter case series. Infection [Internet]. 2022 Aug 29 [cited 2022 Sep 21]; Available from: https://doi.org/10.1007/s15010-022-01910-y