. 2021 Sep 20;59(10):e00527-21. doi: 10.1128/JCM.00527-21

TABLE 3.

Calibration of SARS-CoV-2 neutralization assays using first WHO standard for anti-SARS-CoV-2 immunoglobulin

First WHO International Standard for anti-SARS-CoV-2 immunoglobulin	VSV-pseudo/Vero		LV-pseudo/293T		HTS-LV-pseudo/293T
	ND₅₀	ND₈₀	ND₅₀	ND₈₀	ND₅₀	ND₈₀
WHO standard, GMT	1,511	557	3,047	567	4,650	1,396
Calibration factor (1,000 IU/ml ÷ standard GMT)	0.662	1.795	0.328	1.764	0.215	0.716
GMT neutralization titer among participants	309.7	102.8	177.9	41.96	271.7	86.3
Calibrated readout (IU/ml)	205	184.5	58.4	74.0	58.4	61.8