Table 2.

A(H1N1)pdm09 virus-infected critically ill patient antibody responses.

Patient	Samples		HAIa	VNb	ELLAc		BLId
no. (#)	dpo†	dpicu†	CA/09	MX/09	H6N1	rHA	rHA-head	rHA-stem
#1*	8	2	2560	320	320	1.8	0.4	2.5
	28	22	2560	5120	5120‡	4.2	4.6	3.9
#2*	3	3	2560	80	NT	0.7	0.2	0.6
	4	4	2560	80	320	0.3	0.3	0.6
#3	18	1	1280	6400	5120	2.9	3.2	2.4
	41	24	1280	6400	5120	3.6	3.8	2.8
#4	13	7	640	1280	5120	3.9	4.0	2.8
	28	22	1280	2560	5120	3.9	4.4	2.7
#5	18	2	320	1600	5120	3.1	2.6	3.0
	45	29	320	2560	5120	2.9	2.5	2.7
#6	8	1	320	320	1920	2.4	2.2	2.4
	14	7	2560	5120	5120	3.4	3.5	2.6
#7	3	2	320	640	1280	1.2	1.0	0.8
	22	21	12,800	25,600	5120	3.6	3.8	2.7
#8	9	2	160	320	2560	1.6	1.6	1.4
	14	7	5120	12,800	5120	3.6	5.2	2.6
#9	13	2	80	160	2560	2.2	0.8	2.8
	15	4	320	640	5120	2.8	1.9	3.3
#10	9	2	80	80	1280	1.6	1.3	1.8
	18	11	1280	2560	5120	3.8	3.9	3.1
#11*	9	2	80	160	640	1.2	0.7	1.6
#12	5	1	80	160	640	0.8	0.5	1.0
	14	10	640	640	5120	2.7	2.9	2.2
#13	25	5	80	160	640	1.1	0.7	0.9
	40	20	640	1280	1920	2.8	2.3	2.3
#14	2	2	80	160	80	0.5	0.3	0.5
	3	3	1280	320	80	0.9	0.6	0.8
#15	7	2	40	80	2560	1.4	0.5	1.8
	27	22	640	3200	5120	3.1	2.3	2.7
#16	6	1	40	80	80	0.6	0.4	0.5
	12	7	640	5120	5120	3.5	4.1	2.4
#17	7	3	20	40	2560	1.8	0.2	2.4
	11	7	320	1280	5120	3.3	2.7	3.0
#18	6	2	20	40	240	0.6	0.2	0.6
	34	30	2560	5120	5120	3.4	3.7	2.5
#19*	7	3	<	<	1280	2.1	1.4	2.6
	13	9	40	80	3840	1.5	0.6	3.8
#20	3	1	<	<	80	1.5	<	2.2
	9	7	<	20	160	1.4	<	2.1
#21	7	4	<	20	160	1.4	<	2.1
	12	9	20	40	640	2.6	1.6	2.5
#22	17	3	<	<	1280	1.0	0.3	1.7
	36	22	640	1600	5120	3.2	3.0	2.7
#23	10	2	<	<	160	0.8	<	1.6
	29	21	1280	3200	5120	3.7	4.1	2.8
#24	8	1	<	<	640	0.8	<	1.4
	27	20	2560	6400	5120	4.2	3.8	3.4
#25*	8	2	<	<	320	0.3	<	1.0
	13	7	5120	1280	5120	2.7	2.2	2.7
#26	8	2	<	20	160	0.5	<	1.0
	21	15	640	1280	5120	3.7	2.4	3.0
#27	5	4	<	<	320	0.5	<	0.8
	23	22	320	1280	3840	3.0	2.8	2.2
#28	4	2	<	<	160	0.4	<	0.6
	10	8	20	40	2560	2.9	2.1	2.7
#29	5	2	<	<	120	0.2	<	0.4
	16	13	1280	2560	5120	3.8	4.4	2.7
#30	7	2	<	<	40	0.3	0.1	0.4
	9	4	<	20	320	1.3	0.6	1.8
#31	4	1	<	<	320	0.1	<	0.3
	24	21	320	1280	5120	3.5	3.1	2.8

We completed 3 independent HAI and VN assays. BLI and ELLA assays were performed in duplicate.

*Fatal patients in bold; <, titers below 20 in HAI assays and VN assays or ABA < 0.1 nm in BLI assays.

^†dpo, days post-symptom onset; ^†dpicu, days post ICU admission; ^‡Anti-NA titers ≥ 5120; NT, not tested.

^aHAI antibody titers detected by HAI assays using wt-CA/09 (Q223) virus.

^bNeutralizing antibody (VN) titers detected by VN assays with MX/09 (Q223QR mixture) virus.

^cAnti-NA antibody titers detected by ELLA assays using H6N1 virus possessing wt-CA/09 NA.

^dAnti-HA ABA detected by BLI assays using rHA and rHA-head from wt-CA/09, and rHA-stem from A/Michigan/45/2015, respectively.