Table 2.

Antigenic relationships between selected Ligurian Influenza B isolates and B/Brisbane/60/2008 Victoria-lineage reference virus and the deduced amino-acid mutations found on the HA1 coding region with respect to B/Brisbane/60/2008 (reference viruses, homologous titers and epitopes are in bold type).

Influenza B Victoria-lineage Virus (Clade)	HI Titer Post Infection Ferret Antisera B/Brisbane/60/2008 F22/12 1A	Amino-Acid Mutations with Respect to B/Brisbane/60/2008
		120-loop			150-loop
		37	58	80	146
B/Brisbane/60/2008 (1A)	1280	V	L	R	I
B/Genoa/04/2010 (1A)	320	-	-	-	V
B/Genoa/08/2010 (1B)	160	-	P	-	V
B/Genoa/12/2011 (1B)	160	-	P	-	V
B/Genoa/22/2011 (1A)	640	I	-	G	-

V, Valine; L, Leucine; R, Arginine; I, Isoleucine; P, Proline; G, Glycine.