Table 4.

Antigenic analyses of influenza B viruses (Yamagata lineage)

				Haemagglutination inhibition titre
				SS	Post-infection ferret sera
Virus		Collection date	Passage history	B/Florida/4/06 SH479	B/Egypt/144/05 F3/07	B/Florida/4/06 F1/10	B/Brisbane/3/07 F21/12	B/England/145/08 F12/11	B/Bangladesh/3333/07 F25/08	B/Wisconsin/1/10 F7/12	B/Stockholm/12/11 Egg F34/11	B/Estonia/55 669/11 F26/11	B/Serbia/1894/11 F25/11	B/Stockholm/12/11 T/C F8/12
	Genetic group …			1	1	1	2	3	3	3	3	2	3	3
Reference viruses
B/Egypt/144/2005	1	2005-05-01	E3/E5	5120	640	1280	1280	320	640	320	640	160	20	640
B/Florida/4/2006	1	2006-12-15	E3/E3	5120	320	2560	1280	640	640	320	640	160	20	640
B/Brisbane/3/2007	2	2007-09-03	E2/E1	5120	160	640	1280	160	320	160	640	160	10	320
B/England/145/2008	3	not known	Ex/E4	640	<	160	80	320	40	40	80	<	<	80
B/Bangladesh/3333/2007	3	2007-08-07	E4/E4	5120	80	640	320	80	320	80	640	<	20	640
B/Wisconsin/1/2010	3	2007-08-07	E3/E1	1280	80	320	160	160	160	160	160	10	20	320
B/Stockholm/12/2011	3	2007-08-07	E4/E1	5120	160	640	320	160	320	160	640	10	40	640
B/Estonia/55 669/2011	2	2011-03-14	MDCK2/MDCK2	2560	80	320	160	80	20	20	160	640	80	40
B/Serbia/1894/2011	3	2011-03-08	MDCK1/MDCK4	5120	160	320	160	320	160	80	320	160	320	320
B/Stockholm/12/2011	3	2011-03-28	Cx/MDCK4	5120	80	320	160	160	160	80	640	160	320	320
Test viruses
B/Tucumán/A285/2012	2	2012-08-14	MDCK1/MDCK1	2560	40	160	80	40	10	20	160	640	20	20
B/Buenos Aires/8833/2012	2	2012-08-26	MDCK1/MDCK2	1280	<	80	40	20	10	10	80	320	20	20
										Vaccine 2013

SS, Hyperimmune sheep antiserum; E, egg; cell type, MDCK or SIAT (C = cell type unspecified); number of passages required to generate isolate (x = unknown number)/subsequent number of passages to produce sufficient virus for HA/HI analyses.

< = <10, the sheep/ferret reference number is given under the virus name.

Homologous titres are indicated by underlined italics.