Table 6.

Cross-reactivity of FeCoV-specific antibodies with SARS-CoV-2.

Cat ID	RBD M		N M		N E		VN	IFA (SARS-CoV-2)		IFA (FeCoV)
FeCoV pos #1	0.21	Neg	2.17	Pos	2.86	Pos	<1:20	>1:2,400	Pos	>1:6,400	Pos
FeCoV pos #2	0.15	Neg	1.29	Pos	1.32	Pos	<1:20	1:80	Pos	>1:6,400	Pos
FeCoV pos #0	0.18	Neg	1.89	Pos	1.53	Pos	<1:20	1:80	Pos	>1:6,400	Pos
FeCoV pos #3	0.09	Neg	0.2	Neg	0.28	Neg	<1:20	<1:40	Neg	>1:6,400	Pos
FeCoV pos #4	0.11	Neg	0.12	Neg	0.31	Neg	<1:20	<1:40	Neg	>1:6,400	Pos
FeCoV pos #5	0.31	Neg	0.26	Neg	0.37	Pos	<1:20	<1:40	Neg	1:3,200	Pos
FeCoV pos #6	0.12	Neg	0.19	Neg	0.53	Pos	<1:20	<1:40	Neg	>1:6,400	Pos
FeCoV pos #7	0.05	Neg	0.15	Neg	0.16	Neg	<1:20	<1:40	Neg	1:3,200	Pos
FeCoV pos #8	0.07	Neg	0.15	Neg	0.12	Neg	<1:20	<1:40	Neg	>1:6,400	Pos
FeCoV pos #27	0.09	Neg	2.63	Pos	1.74	Pos	<1:20	1:320	Pos	>1:6,400	Pos
FeCoV pos #28	0.28	Neg	2.03	Pos	2.41	Pos	<1:20	1:320	Pos	>1:6,400	Pos
FeCoV pos #29	0.07	Neg	0.97	Pos	1.29	Pos	<1:20	1:80	Pos	1:3,200	Pos
FeCoV pos #30	0.22	Neg	2.87	Pos	2.26	Pos	<1:20	>1:1,280	Pos	>1:6,400	Pos
FeCoV neg #9	0.23	Neg	0.09	Neg	0.55	Neg	<1:20	<1:40	Neg	<1:40	Neg
FeCoV neg #10	0.07	Neg	0.1	Neg	0.21	Neg	<1:20	<1:40	Neg	<1:40	Neg
FeCoV neg #11	0.27	Neg	0.1	Neg	0.24	Neg	<1:20	<1:40	Neg	<1:40	Neg
FeCoV neg #12	0.14	Neg	0.17	Neg	0.41	Neg	<1:20	<1:40	Neg	<1:40	Neg
FeCoV neg #14	0.09	Neg	0.1	Neg	0.1	Neg	<1:20	<1:40	Neg	<1:40	Neg
FeCoV neg #15	0.1	Neg	0.14	Neg	0.17	Neg	<1:20	<1:40	Neg	<1:40	Neg
FeCoV mAb	0.1	Neg	0.27	Neg	0.31	Neg	<1:20	<1:40	Neg	1:400	Pos

FeCoV, feline coronavirus; RBD_M, N_M, mammalian cell-expressed RBD and N, respectively; N_E, E. coli-expressed N; neg, negative; pos, positive; mAb, monoclonal antibody.