Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)-Specific Memory B Cells From Individuals With Diverse Disease Severities Recognize SARS-CoV-2 Variants of Concern.

The unprecedented severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has called for substantial investigations into the capacity of the human immune system to protect against reinfection and keep pace with the evolution of SARS-CoV-2. We evaluated the magnitude and durability of the SARS-CoV-2-specific antibody responses against parental WA-1 SARS-CoV-2 receptor-binding domain (RBD) and a representative variant of concern (VoC) RBD using antibodies from 2 antibody compartments: long-lived plasma cell-derived plasma antibodies and antibodies encoded by SARS-CoV-2-specific memory B cells (MBCs). Thirty-five participants naturally infected with SARS-CoV-2 were evaluated; although only 25 of 35 participants had VoC RBD-reactive plasma antibodies, 34 of 35 (97%) participants had VoC RBD-reactive MBC-derived antibodies.

SARS-CoV-2 specific memory B-cells from individuals with diverse disease severities recognize SARS-CoV-2 variants of concern.

In this investigation we examined the magnitude, breadth, and durability of SARS-CoV-2 specific antibodies in two distinct B-cell compartments: long-lived plasma cell-derived antibodies in the plasma, and peripheral memory B-cells along with their associated antibody profiles elicited after stimulation. We found that magnitude varied amongst individuals, but was the highest in hospitalized subjects. Variants of concern (VoC) -RBD-reactive antibodies were found in the plasma of 72% of samples in this investigation, and VoC-RBD-reactive memory B-cells were found in all but 1 subject at a single time-point.

Neutralization of SARS-CoV-2 variants by convalescent and vaccinated serum.

We tested human sera from large, demographically balanced cohorts of BNT162b2 vaccine recipients (n=51) and COVID-19 patients (n=44) for neutralizing antibodies against SARS-CoV-2 variants B.1.1.