For a study, researchers sought to determine the severity and clinical consequences of the SARS-CoV-2 gamma variant in Brazil’s children and adolescents hospitalized with COVID-19. In this observational retrospective cohort research, they examined all 21,591 hospitalized patients aged 20 years with proven SARS-CoV-2 infection in a Brazilian national database. WAVE1, n = 11 574; WAVE2, n = 10 017). The factors of interest were age, gender, geographic location, ethnicity, clinical presentation, and comorbidities. Time to death was the primary outcome, assessed using competing-risks analysis and cumulative incidence functions. On the basis of the WAVE1 cohort, a predictive Fine and Gray competing-risks model was built, with temporal validation in the WAVE2 cohort. 

Those hospitalized in the second wave had substantially greater hypoxemia (52.5% vs. 41.1%; P<.0001), critical care unit admissions (28.3% vs. 24.9%; P<.0001), and required more noninvasive ventilatory assistance (37.3% vs. 31.6%; P<.0001). In the first wave, there were 896 (7.7%) fatalities and 765 (7.6%) deaths (P=.07). Age, ethnicity, geography, respiratory symptoms, and comorbidities were all factors included in the mortality prediction model. The C statistic in the validation set (WAVE2) was 0.750 (95% CI: 0.741-0.758; P<.0001). The big national investigation discovered a higher severe risk spectrum for juvenile COVID-19 patients caused by the gamma variant. The chance of death, however, did not change between the waves.