Growth kinetics of BQ.1.1. Clinical isolates of BA.2, BA.5, BQ.1.1 and Delta were inoculated into an airway-on-a-chip system. The copy numbers of viral RNA in the apical sides of cultures, and the top and bottom channels of an airway-on-a-chip were routinely quantified by RTqPCR. In the right, the percentage of viral RNA load in the bottom channel per top channel during 36 d.p.i. (i.e., the % invaded virus from the top channel to the bottom channel) is shown. Assays were performed in triplicate. The presented data are expressed as the average standard error of mean (SEM). Statistically significant differences versus BA.5 across timepoints were determined by multiple regression. The familywise error rates (FWERs) calculated using the Holm method are indicated in the figures. NA, not applicable.
