SARS-CoV-2 B.1.1.529 (Omicron) Variant Causes an Unprecedented Surge in Children Hospitalizations and Distinct Clinical Presentation Compared to the SARS-CoV-2 B.1.617.2 (Delta) Variant

Abstract

BackgroundIn the midst of successive waves of SARS-CoV-2 variants, the B.1.1.529 (omicron) variant has recently caused a surge in pediatric infections and hospitalizations. This study aimed to describe and compare the symptoms, explorations, treatment and evolution of COVID-19 in hospitalized children during the successive B.1.617.2 (delta) and B.1.1.529 (omicron) waves.MethodsThis observational study was performed in the Pediatric Pulmonology Department of a University Hospital in Paris, France. All hospitalized children aged between 0 and 18 years who tested positive for SARS-CoV-2 using reverse transcription polymerase chain reaction (RT-PCR) in nasopharyngeal swabs from July 15th to December 15th 2021 (delta wave), and from December 15th 2021 to February 28th 2022 (omicron wave) were included.ResultsIn total, 53 children were included, 14 (26.4%) during the delta wave and 39 (73.6%) during the omicron wave (almost three times as many hospitalizations in half the time during the latter wave). During the omicron wave, hospitalized patients were mostly aged < 5 years (90 vs. 71% of all the children during omicron and delta waves, respectively), and tended to have fewer underlying conditions (56 vs. 79% during omicron and delta waves, respectively, p = 0.20). The omicron variant was also responsible for a different clinical presentation when compared to the delta variant, with significantly higher and often poorly tolerated temperatures (p = 0.03) and increased digestive symptoms (p = 0.01). None of the three patients who were older than 12 years were fully vaccinated.ConclusionThe dramatic increase in the hospitalization of children with COVID-19 and the modification of the clinical presentation between the latest delta and omicron waves require pediatricians to remain vigilant. It should also encourage caregivers to ensure vaccination in children older than 5 years, for whom the BNT162b2 COVID-19 vaccine has been deemed safe, immunogenic, and effective.

Variability in the Clinical Course of COVID-19 in a Retrospective Analysis of a Large Real-World Database

“…The incidence of gastrointestinal symptoms such as nausea and diarrhea were comparable in the Omicron and Delta waves, while vomiting was reported significantly more often. The changes in the clinical picture of the disease reported in our study during the emergence and dominance of the Omicron strain were described in many other analyses that compared the severity of SARS-CoV-2 infections during periods dominated by different viral variants [ 25 , 30 , 36 ].…”

“…In the present study, the lower mean age of patients admitted to the hospital during the Omicron wave compared to previously analyzed periods resulted from a significantly higher percentage of those under the age of 20. The phenomenon of an unprecedented increase in the number of hospitalizations of children and adolescents in the Omicron surge has been pointed out by other authors [ 25 , 30 , 31 ]. In contrast, analyses that were conducted only in the adult population, and evaluated patients hospitalized in different waves of the pandemic in different countries including Poland, reported an increase in the mean age of patients during the Omicron wave [ 8 , 32 ].…”

Omicron Wave Modification of the Coronavirus Disease 2019 Paradigm in Children With Cystic Fibrosis

“…The incidence of COVID-19 worldwide has been far lower in children than in adults until the appearance of the variant of concern B.1.1.529 (Omicron). Omicron has been shown to cause a dramatic increase in pediatric infections and hospitalizations in comparison with the previous variants [2,3]. The higher infectivity of this Omicron variant has been attributed to mutations in the spike glycoprotein-binding human ACE2, resulting in increased infectivity of nasal epithelial cells and ACE2-positive cells [4].…”

COVID‐19 and pediatric pulmonology: Feedback from an expert center after the first year of the pandemic

“…In late 2021–early 2022, a resurgence of cases in young adults and children was observed with the delta and omicron variants in France. 5 , 6 , 7 This has caused the recrudescence of severe COVID‐19 forms and hospitalizations in children, particularly in the age group of 0–9 years because of the limited vaccination coverage in this population. 7 , 8 , 9 , 10 …”

“… 5 , 6 , 7 This has caused the recrudescence of severe COVID‐19 forms and hospitalizations in children, particularly in the age group of 0–9 years because of the limited vaccination coverage in this population. 7 , 8 , 9 , 10 …”