Table 7. Antigenic analysis of H5/97 and H5_S223→N/97 viruses with polyclonal and monoclonal antibodies.

	HI titer of polyclonal antisera
	A/ck/Hida lgo/94	A/HK/156/97	A/Gs/HK/4 97-4/97	A/ck/HK/YU2 2/02	A/HK/213/03		HI titer of mAbs
Virus						ΔH5/03	VN04-6*	HK03-3†	CP58‡	CP24‡	CP46‡	CP406/7‡
ΔH5/03	20	320	5,120	12,800	160	5,120	25,600	6,400	1,600	12,800	<100	1,600
H5/97	40	640	640	320	<10	10	3,200	<100	3,200	1,600	<100	3,200
H5S223→N/97	320	10,240	10,240	2,560	80	1,280	25,600	<100	25,600	51,200	200	25,600

HI test was performed in microtiter plates with 0.5% chicken RBCs (14). Titers are the reciprocal lowest dilutions of sera that inhibited hemagglutination caused by 4 HAU of virus.

^*Anti-HA mAb to A/Vietnam/1203/04 virus.

^†Anti-HA mAb to A/HK/213/03 virus.

^‡Anti-HA mAb to A/chicken/Pennsylvania/1370/83 virus.