Table 3.

H9 and H5 HI results for pre-HPAI H5N1 challenge serum from LAIV-vaccinated ferrets^a

Group	Animal no.	H9 HI titer	H5 HI titer
H9N2-GFP	709	160	<10
	710	320	<10
	711	320	<10
	712	320	<10
	713	160	<10
	714	320	<10
H9N2-H5	715	80	<10
	716	40	<10
	718	80	10
	719	80	10
	720	160	<10
PBS	721	<10	<10
	722	<10	<10
	723	<10	<10
ΔH5N1	724	<10	40
	725	<10	20
	726	<10	<10

^aSerum was obtained from animals 13 days post-boost vaccination. Serum samples were treated with receptor-destroying enzyme (Accurate Chemical and Scientific Corp., Westbury, NY) to remove nonspecific receptors, and the antiviral antibody titers were evaluated using an HI assay as outlined in the WHO Manual for the Laboratory Diagnosis and Virological Surveillance of Influenza (28). H9N2 wt and ΔH5N1 were used in these assays. HI titers are reported as the reciprocal of the highest dilution of serum that showed activity against the corresponding virus. HI titers for each animal are shown. The limit of detection for this technique is 10.