Four times more children hospitalized during Omicron’s COVID wave compared to Delta
Since the start of the coronavirus disease 2019 (COVID-19) pandemic, several variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged.
Study: Hospitalizations of children and adolescents with laboratory-confirmed COVID-19—COVID-NET, 14 states, July 2021-January 2022. Image Credit: jeep5d / Shutterstock.com
The recent variant of Omicron was first reported in the United States on December 1, 2021; however, on December 25, 2021, Omicron quickly became the dominant strain of SARS-CoV-2 circulating in the United States. Although hospitalizations related to COVID-19 are more frequent in adults, they can also have serious consequences in children and adolescents.
Several studies have indicated that hospitalizations associated with COVID-19 in children and adolescents peaked during the dominant Delta and Omicron periods. Infection rates during the Omicron peak were significantly higher compared to those reported during the Delta peak. Therefore, implementing COVID-19 prevention strategies in adolescents and children is important.
A new study published at the US Centers for Disease Control and Prevention (CDC) Morbidity and Mortality Weekly Report is analyzing data from the COVID-19-Associated Hospitalization Surveillance Network (COVID-NET) to determine COVID-19-associated hospitalizations in children ages 0-11, as well as adolescents ages 12-17. The data used in this study was acquired from the Delta-dominant period between July 1, 2021 and December 18, 2021 and the Omicron-dominant period from December 19, 2021 to January 22, 2022 in the United States.
Weekly rates of hospitalizations associated with COVID-19* among children and adolescents aged 0–17, by age group—COVID-NET, 14 states,† July 3, 2021–January 22, 2022
About the study
The current study involved the collection of data that serve as indicators of severe disease, including length of hospital stay, use of invasive mechanical ventilation (IMV), admission to an intensive care unit (ICU ) and the symptoms present on admission of the patient. Hospitalizations associated with COVID-19 have been confirmed by a positive SARS-CoV-2 reverse transcription-polymerase chain reaction (RT-PCR) or rapid antigen detection test.
Weekly hospitalization and ICU admission rates were calculated by dividing the total number of hospitalized patients by the population estimates in each age group. For adolescents, the hospitalization rate was calculated by COVID-19 vaccination status, as this was the only age group included in the study who was eligible for vaccination. Subsequently, the proportions were compared between the Delta and Omicron predominance periods.
Hospitalizations peaked in the weeks ending September 11, 2021 and January 8, 2022, during the Delta and Omicron predominant periods, respectively, with Omicron’s peak hospitalization rate four times higher than those reported during the Delta period. . Hospitalization rates for children aged 0-4 years were five times higher during the Omicron period compared to the Delta period.
In December 2021, when the Delta and Omicron variants were circulating, hospitalization rates were 23.5 and 3.8 per 100,000 among unvaccinated and fully vaccinated adolescents. Notably, the proportion of adolescents fully immunized during the Delta period was lower than that of the Omicron period, which may result in higher rates of hospitalization and intensive care unit admissions. In addition, rates of intensive care requirements and IMV use among hospitalized children and adolescents were lower during the Omicron period.
Overall, the current study demonstrates that the emergence of SARS-CoV-2 Delta and Omicron variants have caused serious illness and hospitalizations in children and adolescents. Among adolescents, hospitalization was lower in vaccinated people than in unvaccinated people. More research needs to be conducted to monitor hospitalization rates associated with COVID-19 as more children and adolescents are fully immunized.
Testing practices and test availability may have provided inaccurate data on hospitalizations. A second limitation of the current study was that the availability of detailed clinical data during the Omicron period was brief and initially coincided with the Delta circulation period. Moreover, it was not possible to take seasonality into account when comparing the predominance of the two variants.
The number of children eligible for vaccination during the study was small, in part because children between the ages of five and 11 were not yet fully vaccinated and therefore were not included in the study. the study. It should also be noted that the results of the current study may not be generalizable to the entire United States.
- Marks, KJ, Whitaker, M., Anglin, O., et al. (2022). Hospitalizations of children and adolescents with laboratory-confirmed COVID-19—COVID-NET, 14 states, July 2021-January 2022. Weekly report on morbidity and mortality. doi:10.15585/mmwr.mm7107e4.