Table 2. Serological status, as determined by hemagglutination inhibition, of chickens 15 days after experimental pre-exposure to H7N2 LPAIV^a and 10 days after challenge with H7N1 HPAIV^b.

	HI Titerc
Group Bird identification		15 days post-H7N2/LP exposure (Day 15)		10 days post-H7N1/HP challenge (Day 25)
		H7d	H5e	H7	H5
G1
1		16	<4	32	<4
2		32	<4	64	<4
3		8	<4	8	<4
4		<4	<4	32	<4
5		64	<4	128	<4
6		32	<4	64	<4
G2
7		<4	<4	†	†
8		<4	<4	†	†
9		<4	<4	†	†
10		<4	<4	128	<4
11		<4	<4	†	†
12		<4	<4	128	<4
G3
13		<4	<4	<4	<4
14		<4	<4	<4	<4
15		<4	<4	<4	<4
16		<4	<4	<4	<4

Sera from the animals were tested against H7 and H5 antigens.

^aChickens were inoculated intranasally with A/Anas plathyrhynchos/Spain/1877/2009 (H7N2) (10^5.5 ELD₅₀). Serologic data from six randomly selected birds per group are presented.

Due to the lack of seroconversion, only four animals from the naïve group are represented in the table.

^bChickens were challenged intranasally with A/FPV/Rostock/34 (H7N1) (10^5.5 of ELD₅₀) 15 days after the pre-exposure to H7N2 LPAIV.

^cHI titers ≥8 were considered positive.

^dHI using antigen against H7N3 subtype.

^eHI using antigen against H5N1 aubtype.

^† = succumbed to H7N1 HPAIV-infection.