In Figure 5 , pseudovirus neutralization assay results were plotted against PRA results (Wuhan type) to compare their reliability. Plots showed linearity with a measure of certainty of R2 = 0.7 (p= 0.0006) for pseudovirus neutralization against PRA with isolated authentic virus (Figure 5A) . The measure of certainty (R2) was decreased for pseudovirus bearing Spike protein of Alpha and Betavariants against the PRA with Wuhan strain (Figure 5B and 5C ). Linearity test of pseudovirus bearing Spike protein ofAlpha variant was less significant for the comparison of pseudovirus bearing Spike protein of Wuhan strain versus PRA (R2 = 0.31, p= 0.048). In general, the pseudovirus neutralization assay overestimated the samples with low neutralizing activities determined by PRA. It might be less reliable for plasma samples with low neutralizing capacity.