Multiplex Evaluation of Influenza Neutralizing Antibodies with Potential Applicability to In-Field Serological Studies

Table 1

Comparison of neutralizing activity of a panel of sera collected from chickens vaccinated with an inactivated H5N2 monovalent vaccine.

Serum number	H5 positive sera (H5N2 monovalent vaccine)
	GMT titres; H5N1 A/Vietnam/1194/04	GMT titres; H5N1 A/Indonesia/5/05	GMT titres; H7N1 A/chicken/13474/99	HI titres; H5N2 A/chicken/Italy/80
1	2560	2560	28	2048
2	2560	2560	113	2048
3	640	1280	10	512
4	1810	2560	10	2048
5	453	453	10	1024
6	1280	905	28	1024
7	226	226	10	512
8	113	160	113	128
9	640	905	28	512
10	640	453	57	512
H5N1+	1280	—	—	—
Negatives (40 tot.)	≤1 : 10	≤1 : 10	—	1 : 2

GMT titres were calculated and expressed as the reciprocal of serum dilution at which a 50% inhibition of pseudotype (IC₅₀) entry was observed.