Table 3.

NAI titres from the indicated N2 reassortant viruses and antisera.

	ɑ-N2-HK19c	ɑ-N2-HK19e	ɑ-N2-KS17	ɑ-N2-SG16	ɑ-N2-HK14	ɑ-N2-SW13
PR8N2-VA20 a	124	143	29	77	62	21
PR8N2-MN20	270	152	99	117	87	22
PR8N2-MI20	231	129	53	44	37	8
PR8N2-PA20 a	103	149	27	31	24	8
PR8N2-CA20	420	267	139	175	151	34
PR8N2-OH20 a	167	178	47	100	101	17
PR8N2-MA20 b	292	111	77	138	110	22
PR8N2-Que20 c	2509	668	605	725	765	98
PR8N2-HK19c	333	189	96	123	86	25
PR8N2-HK19e	160	213	37	95	83	22
PR8N2-KS17	2181	909	729	713	598	99
PR8N2-SG16	199	99	75	104	64	27
PR8N2-HK14	19	68	9	24	239	245
PR8N2-SW13	30	72	12	32	342	336

NAI titres represent the mean IC₅₀ values for each ferret antiserum (italics) against the indicated viruses that were determined from an ELLA performed in duplicate. Titres from PR8 reassortant viruses where the N2 sequence matches the N2 used to generate the ferret antisera are in bold. All ferret antisera were produced by intranasal inoculation with PR8 reassortant viruses carrying H6 with the indicated NA. Source data are provided in the source data file.

^aN2 possesses the 469 T substitution present in N2-HK19e.

^bN2 contains a potential N-linked glycosylation site at 463 N.

^cN2 sequence is more similar to N2-KS17 than N2-HK19c or N2-HK19e.