Correlation between Commercial Anti-RBD IgG Titer and Neutralization Titer against SARS-CoV-2 Beta Variant.

Objectives: The emergence of SARS-CoV-2 variants of concern (VOCs) have diminished the effectiveness of vaccines and are associated with a rebound in the number of COVID-19 cases globally. These variants contain mutations at the spike (S) protein receptor binding site (RBD), which affect antibody binding. Current commercially available antibody assays were developed before the VOCs emerged.

The impact of spike N501Y mutation on neutralizing activity and RBD binding of SARS-CoV-2 convalescent serum.

Background: Several SARS-CoV-2 lineages with spike receptor binding domain (RBD) N501Y mutation have spread globally. We evaluated the impact of N501Y on neutralizing activity of COVID-19 convalescent sera and on anti-RBD IgG assays.

Methods: The susceptibility to neutralization by COVID-19 patients' convalescent sera from Hong Kong were compared between two SARS-CoV-2 isolates (B117-1/B117-2) from the α variant with N501Y and 4 non-N501Y isolates.