Figure 2. Ct value patterns across all variants in study of SARS-CoV-2 disease severity in children during pre-Delta, Delta, and Omicron periods, Colorado, USA, January 2021–January 2022. Boxplots indicate overall Ct value patterns across categories of patient characteristics, regardless of variant period. A) Age group; B) vaccination status (unvaccinated vs. vaccinated with any number of doses); C) vaccination status (unvaccinated versus vaccinated by number of doses); D) patient type (outpatient/not hospitalized, hospitalized because of COVID-19, hospitalized but not because of COVID-19); E) symptomatic versus asymptomatic; F) number of days between symptom onset and positive test (symptom onset groups); G) hospitalized but not admitted to PICU versus admitted to PICU; H) any type of supplemental oxygen support versus no oxygen support received; I) highest level of supplemental oxygen support received (none, noninvasive oxygen support, invasive oxygen support). Significance was determined using 1-way analysis of variance with Tukey test. Brackets indicate which comparisons correspond to the significance codes, and connected brackets indicate comparisons that have the same significance code. Ct, cycle threshold; PICU, pediatric intensive care unit.