Fig. 4

Co-infection of H1N1 and SARS-CoV-2 in K18-hACE2 mice. a Experimental design and sample collection in K18-hACE2 mice. b Changes in body weight and percent survival were recorded at the indicated time points in H1N1-infected K18-hACE2 mice (K18/F), SARS-CoV-2-infected K18-hACE2 mice (K18/C), and co-infected K18-hACE2 mice (K18/FC) (n = 6). c Pathogenesis of H1N1 and SARS-CoV-2 in K18/F, K18/C, and K18/FC mice. d Histopathological changes in K18/F, K18/C, and K18/FC dying mice. e Immunofluorescence analysis of K18/F, K18/C, and K18/FC mice. Black bar = 100 μm, white bar = 25 μm, yellow bar = 75 μm