Table 2.

Selected specifications and test characteristics of a subset of 20 COVID-19 antibody detection rapid diagnostic tests (RDTs) retrieved from 20 products' instructions for users (IFU).

Product specifications	Nr	%
RECOMBINANT DETECTION ANTIGEN
° Spike protein	3	15.0%
° Nucleocapsid protein	0	0.0%
° Spike and Nucleocapsid protein	3	15.0%
° Not mentioned	14	70.0%
FORMAT, CONFIGURATION, PACKAGE
° Strip-in-cassette	20	100.0%
° Strip-in-tube	0	0.0%
° Sampling material in kit	4	20.0%
° Transfer device in kit	15	75.0%
° Self-contained kit (containing both sampling materials and transfer device)	20	100.0%
° Controls included in the kit	1	5.0%
CLAIMED SPECIMENS
° Plasma / Serum	2	10.0%
° Serum/ Plasma/ Whole blood	8	40.0%
° Serum/ Plasma/ Whole blood including capillary finger prick blood	8	40.0%
° Serum/Plasma/Whole blood but not recommended for finger prick blood	2	10.0%
REPORTING OF SENSITIVITY
° Sensitivity expressed in function of time since symptom onset	5	25%
STORAGE TEMPERATURE
° 2/4°C up to 30 °C	20	100.0%
OPERATING CONDITIONS AND IN-USE STABILITY (STABILITY
AFTER OPENING THE DEVICE POUCH)
° Operating conditions mentioned	0	0%
° In-use stability 30 min	1	5.0%
° In-use stability 1 h	3	15.0%
° No in-use stability mentioned, “process immediately”	16	80.0%
SHELF-LIFE
° 2 months	1	5.0%
° 6 months	1	5.0%
° 12 months	3	15.0%
° 18 months	2	10.0%
° Not mentioned in IFU	13	65.0%
RESULT STABILITY
° 15 min	5	25.0%
° 20 min	11	55.0%
° 30 min	1	5.0%
° Not mentioned in IFU	3	15.0%
° SAMPLE STABILITY
° Capillary blood finger prick: “perform immediately” (all 8 products)
° Venous whole blood: 2–7 days at 4–8°C (median 3)
° Serum/Plasma: 2–7 days at 4–8°C (median 3)
° Not mentioned for 9 (45%) products

All RDTs are lateral-flow immunochromatography assays. Numbers refer to the number of COVID-19 RDT products.