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. 2021 Aug 20;24(9):103006. doi: 10.1016/j.isci.2021.103006

Figure 2.

Figure 2

Neutralizing antibody titers and RBD binding antibodies of convalescent plasma and hCoV-2IG against various SARS-CoV-2 strains

(A) SARS-CoV-2 neutralizing antibody titers in each of the CP, 2019-IVIG and hCoV-2IG preparations as determined by pseudovirus neutralization assay in 293-ACE2-TMPRSS2 cells with SARS-CoV-2 WA-1 strain, CA variant (B.1.429), UK variant (B.1.1.7), JP variant (P.1) or SA variant (B.1.351). PsVNA50 (50% neutralization titer) and PsVNA80 (80% neutralization titer) titers for each of the control pre-pandemic 2019-IVIG (n = 16), convalescent plasma (n = 9) and hCoV-2IG (n = 6) were calculated with GraphPad prism version 8. Data show mean values ±SEM for PsVNA50 and PsVNA80 titers for each of the 3 antibody groups against the SARS-CoV-2 WA-1, CA, UK, JP and SA variants. If all CP lots or 2019-IVIG lots have titer <20, then they are shown as titer of <20. If any of the CP or 2019-IVIG showed PsVNA50 or PsVNA80 titers >20, then the average values are shown for the group against specific SARS-CoV-2 strain.

(B) End-point virus neutralization titers for six hCoV-2IG lots (different colors) using wild type authentic SARS-CoV-2 WA-1, UK and SA virus strains in a classical BSL3 neutralization assay based on a plaque assay was performed as described in Materials and Methods.

(C) Pearson two-tailed correlations are reported for the calculation of correlation of PRNT50 titers against wild-type SARS-CoV-2 strains (WA-1, UK or SA) and PsVNA50 titers against corresponding pseudovirions expressing either WA-1, UK or SA spike in pseudovirion neutralization assays for the six hCOV-2IG lots.

(D) Antibody concentration (in mg/mL) required for each of the six hCoV-2IG batches to achieve 50% neutralization of SARS-CoV-2 WA-1, CA, UK, JP or SA variants in PsVNA. Only the WA-1 strain had a significant difference compared to the JP and the SA strain.

(E and F) The fold-decrease in PsVNA50 neutralization titers against emerging variant strain CA (B.1.429), UK (B.1.1.7), JP (P.1) and SA (B.1.351) for six hCoV-2IG lots (E) and nine CP lots (F) in comparison with the SARS-CoV-2 WA-1 strain is shown. The numbers above the group indicates the mean fold-change for each variant.