On Jan. 19, 2021, ImmunityBio reported findings from a follow-up Molecular Dynamics simulation study of the SARS-CoV-2 spike receptor binding domain (RBD) and its binding to its receptor on human cells, angiotensin-converting enzyme 2 (ACE2).

A notable finding was that the combination of E484K, K417N and N501Y, found only in the South African variant, resulted in the highest degree of conformational alterations of S RBD when bound to hACE2, compared to either E484K or N501Y alone. Conformation affects the recognition of an antibody to an antigen site.