Driving consistency: CEPI-Centralized Laboratory Network’s conversion factor initiative for SARS-CoV-2 clinical assays used for efficacy assessment of COVID vaccines

Figures & data

Table 1. A summary of the data obtained from all facilities for the WHO IS 21/340 is presented. The conversion factor for WHO IS 21/340 was determined for the Victoria strain.

	WHO IS 21/340
	Spike-ELISA	RBD-ELISA	N-ELISA	MNA	PNA
Assigned Unitage	652 BAU/mL	723 BAU/mL	563 BAU/mL	1424 IU/mL	1424 IU/mL
Number of Results	90	90	66	59	58
Geometric Mean	4540.2 ELU/mL	5939.2 ELU/mL	4428.9 ELU/mL	3499 ND50	3954 NT50
Conversion Factor	6.9635	8.2147	7.8665	2.46	2.7768