Fig. 4 ∣. Intranasally delivered IgM-14 confers protection against SARS-CoV-2 VOCs.

a, Experimental design for the evaluation of antibody bio-distribution. b, Representative whole-body images. c, Representative ex vivo images. Bl, blood (20 μl); Br, brain; H, heart; K, kidney; Lu, lung; Lv, liver; N, nasal cavity; S, spleen. d, Quantification of fluorescence signals. Data are mean ± s.d. of four mice. Dashed line shows the average autofluorescence of organs. e, Experimental design of dose-range evaluations of IgM-14 against a mouse-adapted SARS-CoV-2 (CMA4 strain). For prophylactic treatment, IgM-14 was evaluated at two sets of dose ranges to determine the minimal effective dose. f, g, Viral loads in the lungs of CMA4-infected mice after prophylactic (f) or therapeutic (g) treatment with IgM-14. n = 10 biologically independent mice for all groups, except for the 1.2 mg kg⁻¹ group in g (n = 15). h, i, Viral loads in the lungs of mice infected with the P.1 (h) and B.1.351 (i) variant, after therapeutic treatment as indicated. n = 5 biologically independent mice for all groups. The solid lines in f–i indicate median viral loads in the lung. An ordinary one-way ANOVA with Sidak’s multiple comparisons was used in the statistical analysis for f, g. A two-sided Mann–Whitney test was used in the statistical analysis for h, i.