Figure 3. Ct value patterns of patient characteristics across variant periods 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 among patient characteristics across variant periods. A) Variant period; B) age group; C) vaccination status (unvaccinated vs. vaccinated with any number of doses); D) vaccination status (unvaccinated vs. vaccinated by number of doses). Red = pre-Delta, Blue = Delta, Orange = Omicron. Significance was determined using 1-way analysis of variance (A) or 2-way (B–D) 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.