Fig. 4: Comparison of viral dynamics between B.1.1.7 and non-B.1.1.7 viruses.

a–d, Comparison of viral dynamics between B.1.1.7 and non-B.1.1.7 viruses based on nasal (a,b) and saliva samples (c,d). a,c, Viral genome load of B.1.1.7 infections (purple) and non-B.1.1.7 infections (pink) over time, as measured by RT–qPCR (dots). Ribbons indicate 90% CIs of predicted CN and Ct value trajectories, respectively, using population parameters estimated from modelling analysis (Supplementary Table 4). b,d, Comparison of estimated values for indicated summary statistics of viral dynamics between individual B.1.1.7 and non-B.1.1.7 infections (n = 14 and 42 for B.1.1.7 and non-B.1.1.7 infections, respectively). Boxes in boxplots start in the first quartile and end in the third quartile of the data (for example, IQR), and lines within boxes represent the median; whiskers represent 1.5× IQR and filled circles represent outliers. P values for Wilcoxon rank-sum test are reported. b, Note that, because age covaries with total infectious virus shed (Fig. 3f), comparison of total infectious virus shed after adjusting for age is shown (Methods).