Table 1.

Stability of COVID-19 antibodies under various conditions of temperature and humidity.

	Length of storage (days)
Storage conditions	0	1	3	7	14	21	28
–20°C, low humidity	100	93	100	103	101	97	97
–20°C, ambient humidity	100	107	109	99	109	97	90
+4°C, low humidity	100	99	102	104	105	92	102
+4°C, ambient humidity	100	105	98	104	97	92	92
RT, low humidity	100	107	103	103	99	96	102
RT, ambient humidity	100	99	104	103	102	97	93
RT, high humidity	100	97	102	102	91	92	94
40°C, low humidity	100	108	101	96	95	90	91
40°C, ambient humidity	100	107	97	96	94	90	97
40°C, high humidity	100	81	65	57	45	29	27

DBS specimens were stored at the various temperatures and conditions. At the various time intervals, samples were removed and stored desiccated in sealed foil bags at –20°C prior to analysis in duplicate at the end of the study. Results shown are % residual OD, using DBS specimens that were stored desiccated at –20°C, during the study period as the control (i.e. 100%) and analysed alongside those specimens subjected to the various heat and humidity conditions. The mean (SD) OD for the 100% control was 1.52 (0.14).