Fig. 1

Replication of SARS-CoV-2 NL-02-2020, Delta and Omicron variants in human cardiomyocytes. a Replication kinetics of the SARS-CoV-2 NL-02-2020, Delta and Omicron BA.1 variants in human cardiomyocytes at the indicated days post-infection. b Infectious SARS-CoV-2 particles in the supernatants of cardiomyocytes infected at an MOI of 1 at 4 and 6 days post-infection (indicated by arrows in panel a). TCID50 was determined by infection of CaCo-2 (day 4 pi) and Vero E6 (day 6 pi) cells as described in the methods section. b.d.l, below detection limit. c Confocal images showing the effect of SARS-COV-2 variants infection on cardiomyocytes sarcomeric organization. d Number of beats/30 sec observed in uninfected or SARS-CoV-2-infected cell cultures (also see supplementary movie 1). e IFNs and proinflammatory cytokines production in the supernatants of (a) at MOI 1, day 4 post-infection. f Replication kinetics of SARS-CoV-2 Omicron BA.1, 2 and 5 variants in cardiomyocytes. g Infectious SARS-CoV-2 particles in the supernatants of cardiomyocytes infected at an MOI of 0.1 and obtained at 4 days post-infection (highlighted by an arrow in panel f). TCID50 was determined by infection of Vero E6 cells. h Number of beats/30 sec observed in uninfected or SARS-CoV-2 Omicron BA.1, BA.2 and BA.5 infected cardiomyocyte cultures (also see supplementary movie 2). All panels show results obtained from three biological replicates (n = 3, Mean ± SEM). Significant differences compared to BA.1 are indicated as: *p < 0.05; **p < 0.01; ***p < 0.001; ns not significant