Coronavirus Disease 2019 Disease Severity in Children Infected With the Omicron Variant

Abstract

Background There are limited data assessing COVID-19 disease severity in children/adolescents infected with the Omicron variant. Methods We identified children and adolescents <18 years with SARS-CoV-2 infection with Delta and propensity-score matched controls with Omicron variant infection from the National COVID-19 Database in Qatar. Primary outcome was disease severity, determined by hospital admission, admission to ICU, or mechanical ventilation within 14 days of diagnosis, or death within 28 days. Results Among 1,735 cases with Delta variant infection between June 1 and November 6, 2021 and 32 635 cases with Omicron variant infection between January 1 and January 15, 2022 who did not have prior infection and were not vaccinated, we identified 985 propensity-score matched pairs. Among Delta infected, 84.2% had mild, 15.7% had moderate, and 0.1% had severe/critical disease. Among Omicron infected, 97.8% had mild, 2.2% had moderate, and none had severe/critical disease (P < .001). Omicron variant infection (vs. Delta) was associated with significantly lower odds of moderate or severe/critical disease (adjusted odds ratio, 0.12; 95% CI 0.07-0.18). Those aged 6–11, and 12-<18 years had lower odds of developing moderate or severe/critical disease compared with those younger than six years (aOR, 95% CI 0.47; 0.33-0.66 for 6-11 year old; aOR 0.45, 95% CI 0.21-0.94 for 12-<18 years old). Conclusions Omicron variant infection in children/adolescents is associated with less severe disease than Delta variant infection as measured by hospitalization rates and need for ICU care or mechanical ventilation. Those 6 to <18 years also have less severe disease than those <6 years old.

Clinical characteristics of COVID-19 in hospitalized children during the Omicron variant predominant period

“…Wang et al performed a propensity score matching cohort study in children younger than 5 years in the United States that revealed that risks for hospitalizations and ICU admissions were lower in the patients <5 years old in the Omicron variant predominant period than those in the Delta predominant period. Another propensity matched cohort study conducted in Qatar reported that the patients with the Omicron variant infection had less severe disease [ 17 ]. In our study, more patients required noninvasive oxygen support in the Omicron variant predominant period than in the Delta variant predominant period; however, the ICU admission rates in those two periods were similar and no patients died.…”

Effects of wearing FFP2 masks on SARS-CoV-2 infection rates in classrooms

“…In response, stringent mitigation measures were relaxed worldwide. 39,40 Our data show that this (at least in school settings) apparently led to "catch-up" infections in those thus far protected from infection with SARS- . By the end of our data collection (April 2022), only a small difference in cumulative infection rates was observed between students with strict mask wearing rules during the highincidence period and those without.…”

Convolutional Neural Networks Based on Sequential Spike Predict the High Human Adaptation of SARS-CoV-2 Omicron Variants

“…Thus, the CNN based on sequential Spike predicting the higher human adaptation of the BA.2 sublineage was consistent with pandemic facts. In the context of COVID-19 disease severity, post-SARS-CoV-2 infection, decreasing pathogenicity was reported by recent variants compared to others in the early stages of the COVID-19 pandemic [ 33 ]. However, there is not yet conclusive about the severity difference between Omicron BA.1 and BA.2 sublineages.…”