Fig. 3: Neutralizing activity of anti-SARS-CoV-2 RBD monoclonal antibodies.

a, SARS-CoV-2 pseudovirus neutralization assay. IC₅₀ values for antibodies cloned from patients who had recovered from COVID-19 measured at 1.3 and 6.2 months^5,6 after infection, as well as antibodies cloned from recipients of the Moderna mRNA-1273 (black) and Pfizer–BioNTech BNT162b2 (red) vaccines. Antibodies with IC₅₀ values above 1,000 ng ml⁻¹ were plotted as 1,000 ng ml⁻¹. Mean of two independent experiments. Red bars and indicated values represent geometric mean IC₅₀ values in ng ml⁻¹. Statistical significance was determined using the two-tailed Mann–Whitney U test. Isotype-control antibody was analysed in parallel and showed no detectable neutralization. b, IC₅₀ values for 17 selected monoclonal antibodies for neutralization of wild-type and the indicated mutant SARS-CoV-2 pseudoviruses. Colour gradient indicates IC₅₀ values ranging from 0 (white) to 1,000 ng ml⁻¹ (red). c, Antibody selection pressure can drive the emergence of S variants in cell culture; the percentage of sequence reads encoding the indicated RBD mutations after a single passage of rVSV–SARS-CoV-2 in the presence of the indicated antibodies is tabulated. Colour gradient indicates the percentage of sequence reads that bear the indicated mutation, ranging from 0 (white) to 100 (red). Positions for which no sequence read was detected are shown in grey. The percentages calculated for a given position are based on all the reads, and not only the reads that include that position. Mutations affecting K417, E484 and N501 are highlighted in b, c, as they constitute important circulating variants.