IgG1 ab1

An anti-SARS-CoV-2 spike protein monoclonal antibody.

Phase of research

Potential treatment - pre-clinical evidence

How it helps


Drug status


Supporting references
Contradictory references
AI-suggested references
Clinical trials

General information

IgG1 ab1 is a fully human monoclonal germline-like antibody against the SARS-CoV-2 spike protein RBD identified using phage display technique (as a Fab - converted into full IgG1) (Li et al., 2020).


Supporting references

Link Tested on Impact factor Notes Publication date
Rapid identification of a human antibody with high prophylactic and therapeutic efficacy in three animal models of SARS-CoV-2 infection
Spike protein Animal model Antibody
293T cells expressing the SARS-CoV-2 spike protein; Vero E6 cells; BALB/c mice; hACE2 BALB/c mice; hACE2 C3B6 mice; hamsters; SARS-CoV-2 S pseudotyped HIV-1 virus; mouse ACE2-adapted SARS-CoV-2; wild-type SARS-CoV-2 9.41

The antibody binds to the SARS-CoV-2 spike protein RBD with high affinity (Kd=0.16 nM) (higher than hACE2). It neutralized live SARS-CoV-2 in vitro and induced antibody-dependent cellular cytotoxicity in tissue culture. Upon administration the antibody was shown to act prophylactically (total neutralization at high dose) in mouse models and both prophylactically and therapeutically in hamsters (decreased viral titers, protection of lung tissue).

Cryo-electron microscopy structures of the N501Y SARS-CoV-2 spike protein in complex with ACE2 and 2 potent neutralizing antibodies
Spike protein ACE2 Spike variant Cryo-EM Biophysical assay In vitro Antibody
in vitro biophysical assay; cryo-EM 7.08

The antibody bound both wild type and N501Y Spike ectodomain variants. The affinity for the mutant version was slightly decreased, as was the antibody’s capacity to prevent ACE2 binding. The Fab version of the antibody was shown to bind RBD in the “up” position only.