Fig. 5

Vandetanib reveals a potent antiviral effect against various SCoV2 variants. a A scheme for analysing the antiviral effect of vandetanib (EGFR inhibitor) against various SCoV2 variants. HEK293T cells were infected with SCoV2 (S, V, G, GH and GR clades) and their variants of concern (VOC) including alpha (B.1.1.7), beta (B.1.351), delta (B.1.617.2) and omicron (B.1.529) variants, respectively, at an MOI of 1. At 4 h post-infection, HEK293T cells were washed with fresh cull culture media 5 times and then further incubated in the presence of vandetanib for 44 h. Cell culture media was used for further analyses of real-time qRT-PCR (b) and FFU assay using Vero E6 cells (c). b Real-time qRT-PCR data showing reduced extracellular SCoV2 RNA levels following treatment with vandetanib. Total RNA was isolated from the culture media of HEK293T cells infected with SCoV2 in the presence of vandetanib (10 μM) and then used for analysis of extracellular SCoV2 RNA level by real-time qRT-PCR using PCR primers set specific to the SCoV2 N gene. Data shown are the representative of two independent experiments (mean ± SD; n = 2). DMSO was used as the negative control. c FFU assay data showing the reduction in SCoV2 infectivity following treatment with vandetanib. Cell culture media of SCoV2-infected HEK293T cells post-treated with vandetanib at the indicated concentrations (1, 5 and 10 μM) were transferred to fresh Vero E6 cells and then further incubated for 8 h for FFU assay as described in Materials and Methods. SCoV2, cell culture media of SCoV2-infected HEK293T cells in the presence of vandetanib; Uninfected, cell culture media of SCoV2-uninfected HEK293T cells. The accompanying graphs show the average of two independent experiments (right panel). DMSO was used as the negative control. N.D. not determined