we first determine the expression levels of the ACE-2 receptor and the TMPRSS2 in the different cell lines. Create SARS-CoV-2 pseudovirions, pseudotyped with the prototypical Wuhan, B.1.153, or the B.1.671 S protein variants by using a 2nd generation lentiviral vector. We focused on the pathogenicity of viruses to understand the spectrum of infection in different bodily organs caused by the different variants