Changing Characteristics of Children With COVID-19 in Colorado Admitted During Different Variant Periods.

BACKGROUND: Data are lacking on the impact of different severe acute respiratory syndrome coronavirus 2 variants in children and on pediatric vaccine effectiveness. We examined differences among children requiring hospital admission associated with coronavirus disease 2019 (COVID-19) during wild type, Delta and Omicron variant periods and calculated vaccine effectiveness at preventing symptomatic hospitalization during the Delta and Omicron variant periods. METHODS: We conducted a retrospective review of children younger than 21 years of age hospitalized with symptomatic COVID-19. Characteristics were compared between variant periods using Kruskal-Wallis or generalized Fisher exact tests. We estimated vaccine effectiveness in preventing symptomatic hospitalization. RESULTS: We included 115 children admitted during the wild type period, 194 during Delta and 226 during the Omicron periods. Median age (years) decreased (12.2 wild type, 5.9 Delta, 1.3 Omicron periods, P < 0.0001) over time. Children were less likely to have a comorbid condition, including diabetes or obesity, and had shorter admissions during Omicron compared with the wild type and Delta periods. Intensive care unit admissions and respiratory support requirements were highest during the Delta period (P = 0.05). Among children ≥12 years, adjusted vaccine effectiveness at preventing symptomatic hospitalization was 86% during Delta and 45% during Omicron periods. CONCLUSIONS: Children hospitalized with COVID-19 during later variant periods were younger and less likely to have comorbidities. Children admitted during the Delta variant period required more intensive care and respiratory support compared to other variant periods. Vaccination was less effective at preventing symptomatic hospital admission during the Omicron period compared to the Delta period.

Investigational medications in 9,638 hospitalized patients with severe COVID-19: lessons from the "fail-and-learn" strategy during the first two waves of the pandemic in 2020.

BACKGROUND: The early surge of the novel coronavirus disease 2019 (COVID-19) pandemic introduced a significant clinical challenge due to the high case-fatality rate in absence of evidence-based recommendations. The empirical treatment modalities were relegated to historical expertise from the traditional management of acute respiratory distress syndrome (ARDS) in conjunction with off-label pharmaceutical agents endorsed under the "emergency use authorization" (EUA) paradigm by regulatory agencies. This study was designed to evaluate the insights from the "fail-and-learn" strategy in 2020 before the availability of COVID-19 vaccines and access to reliable insights from high-quality randomized controlled trials. METHODS: A retrospective, multicenter, propensity-matched, case-control study was performed on a data registry comprising 186 hospitals from a national health care system in the United States, designed to investigate the efficacy of empirical treatment modalities during the early surge of the COVID-19 pandemic in 2020. Reflective of the time-windows of the initial two surges of the pandemic in 2020, patients were stratified into "Early 2020" (March 1-June 30) versus "Late 2020" (July 1-December 31) study cohorts. Logistic regression was applied to determine the efficacy of prevalent medications (remdesivir, azithromycin, hydroxychloroquine, corticosteroids, tocilizumab) and supplemental oxygen delivery modalities (invasive vs. non-invasive ventilation) on patient outcomes. The primary outcome measure was in-hospital mortality. Group comparisons were adjusted for covariates related to age, gender, ethnicity, body weight, comorbidities, and treatment modalities pertinent to organ failure replacement. RESULTS: From a total of 87,788 patients in the multicenter data registry screened in this study, 9,638 patients were included who received 19,763 COVID-19 medications during the first two waves of the 2020 pandemic. The results showed a minimal, yet statistically significant, association with hydroxychloroquine in "Early 2020" and remdesivir in "Late 2020" with reduced odds of mortality (odds ratios 0.72 and 0.76, respectively; P = 0.01). Azithromycin was the only medication associated with decreased odds of mortality during both study time-windows (odds ratios 0.79 and 0.68, respectively; P < 0.01). In contrast, the necessity for oxygen supply showed significantly increased odds of mortality beyond the effect of all investigated medications. Of all the covariates associated with increased mortality, invasive mechanical ventilation had the highest odds ratios of 8.34 in the first surge and 9.46 in in the second surge of the pandemic (P < 0.01). CONCLUSION: This retrospective multicenter observational cohort study on 9,638 hospitalized patients with severe COVID-19 during revealed that the necessity for invasive ventilation had the highest odds of mortality, beyond the variable effects observed by administration of the prevalent EUA-approved investigational drugs during the first two surges of the early 2020 pandemic in the United States.