Fig. 3: The activities of IgG4 antibody P4A1–2A to different SARS-CoV-2 S protein mutants, FcRs, and C1q.

a Binding of antibody P4A1 to SARS-CoV-2 S protein N354D/D364Y, R408I, W436R, V367F, or D614G mutants determined by surface plasmon resonance (SPR). b Pseudovirus neutralization assay in hACE2-overexpressing HEK293 cells. Experiment performed in triplicates with symbols represent each of the triplicates. c The binding affinity of P4A1 and P4A1–2A for different human FcRs and complement C1q.