Figure 2 | Scientific Reports

Figure 2

From: Employment of a high throughput functional assay to define the critical factors that influence vaccine induced cross-variant neutralizing antibodies for SARS-CoV-2

Figure 2

Measurement of ACE2-RBD inhibitory response in a surrogate neutralization assay. (A) Left panel: the effect of (i) pre-vaccination plasma, (ii) WHO diagnostic calibrant, (iii) a SARS-CoV-2 neutralizing antibody, and (iv) a SARS-CoV-2 non-neutralizing antibody on inhibiting the interaction between ACE2 and RBD were examined using quartz crystal microbalance technology. Right panel: After RBD interaction with plasma (and antibodies), subsequent signal change during the ACE2 association phase were calculated as a parameter negatively correlated with ACE2 inhibition efficiency. (B) Correlation between neutralizing response by PVNT and ACE2-RBD binding inhibition for Wuhan-Hu-1 RBD at four timepoints were modelled using simple linear regression. N = 672. Pearson’s correlation coefficients and p-values are shown. (C) Pearson’s coefficients and p-values were calculated for the correlation between the IC50 values and neutralization% at 100× dilution of sample (n = 9). (D) ACE2-RBD binding inhibition response was plotted against the PVNT-derived IC50 values after calibration with WHO international standards (n = 13). IC50 values are not available (below 50 IU/mL) for all samples below the arbitrary threshold of 40% ACE2-RBD binding inhibition (n = 4). (E) ACE2-RBD binding inhibition response against Wuhan-Hu-1 RBD was plotted against the neutralizing response measured by PVNT for 15 samples. Size of point represents concentration in IU/mL after calibration with WHO international standards.

Back to article page