February 26, 2021

Bamlanivimab Does Not Neutralize Two SARS-CoV-2 Variants Carrying E484K in Vitro

Category: Article Summary

Topic: Testing and Treatment

Keywords (Tags): antibodies, treatment

• [Pre-print, not peer-reviewed] An in vitro study of the neutralizing ability of the monoclonal antibody treatment bamlanivimab against five emerging SARS-CoV-2 variants of concern determined no neutralization effect could be detected against either the B.1.351 (first described in South Africa) or P.2 (first described in Brazil) variants, both of which harbor the E484K substitution. The antibody was able to efficiently neutralize the B.1.17 variant (first described in the UK), as well as isolates FFM1 and FFM7 from early 2020. These findings indicate screening for E484K substitutions may be needed before initiating monoclonal antibody treatment with bamlanivimab.
• Neutralizing effect of vaccine-elicited sera (following vaccination with the Pfizer-BioNTech COVID-19 Vaccine [BNT162b2]) and convalescent sera were also tested in the 5 variant strains. Vaccine-elicited sera showed neutralizing activity against FFM1 and FFM7, and slightly decreased activity against B1.1.7, B.1.351and P.2. Convalescent sera showed lower neutralizing activity against B1.1.7, B.1.135 and P.2 compared to FFM1 and FFM7. [EDITORIAL NOTE: The manuscript refers to both B.1.351 and B.1.135. It is assumed that B.1.135 was a typographical error and B.1.351 was used throughout in this summary.]

Widera et al. (Feb 26, 2021). Bamlanivimab Does Not Neutralize Two SARS-CoV-2 Variants Carrying E484K in Vitro. Pre-print downloaded Feb 26 from https://doi.org/10.1101/2021.02.24.21252372