Fig. 5: Effect of treatment with paxlovid or molnupiravir on SARS-CoV-2 transmission.

a Transmission study schematic. b–i Direct-contact transmission study. Results are disaggregated into nirmatrelvir/ritonavir (b–e) and molnupiravir (f–i) treatment groups; vehicle-treated animals are shown in both sets. Infectious titers (b, c) and RNA copies (d, e) of SARS-CoV-2 present in nasal lavages of source and contact ferrets. Nasal turbinate titers (f, g) and RNA copies (h, i) in nasal turbinates extracted from source and contact animals on study days 4 and 8, respectively. Symbols (b–e) represent, and lines intersect, geometric means ± SD; x-axes denote level of detection. Symbols (f–i) represent independent biological repeats (results from individual animals); columns denote geometric means ± SD; dotted lines specify level of detection. j nirmatrelvir exposure in selected ferret organs at anticipated peak and trough after single-dose administration of nirmatrelvir + ritonavir. The number of animals (n = independent animals) used in each experiment is specified. Symbols represent independent biological repeats (results from individual animals); columns denote means ± SD. Statistical analysis with one-way (f–i) or two-way (b–e) ANOVA with Dunnett’s post hoc tests (b–e), Kruskal–Wallis test with Dunn’s post hoc tests (f–i), or ratio paired two-sided t test (j); P values are shown. Source data are provided as a Source data file.