Potency of a vaccine prepared from A/swine/Hokkaido/2/1981 (H1N1) against A/Narita/1/2009 (H1N1) pandemic influenza virus strain

Table 1 The cross-reactivity of H1N1 viruses isolated from pigs, humans, and birds

	HI titer of chicken antisera against representative H1 viruses
Virusesa	Narita/09	Sw/Iowa/15/30	Sw/Hok/81	PR/8/34	Hok/4/96	Dk/Mong/540/01
A/Narita/1/2009	5,120b	80	640	40	40	80
Swine isolates
A/swine/Iowa/15/1930	1,280	1,280	2,560	20	80	640
A/swine/Niigata/1/1977	1,280	1,280	2,560	40	160	640
A/swine/Shimane/1/1978	2,560	1,280	5,120	40	160	640
A/swine/Shizuoka/1/1978	2,560	1,280	5,120	40	160	640
A/swine/Toyama/1/1978	2,560	1,280	5,120	40	160	640
A/swine/Kanagawa/1/1978	1,280	1,280	640	40	320	640
A/swine/Hokkaido/2/1981	1,280	1,280	5,120	80	80	640
A/swine/Miyagi/5/2003 (H1N2)	640	320	2,560	160	80	80
Human isolates
A/PR/8/1934	20	40	40	2,560	160	20
A/Hokkaido/2/1996	320	80	80	160	5,120	320
A/Hokkaido/11/2002	160	80	80	320	5,120	80
Avian isolates
A/duck/Miyagi/66/1977	160	80	80	40	40	640
A/swan/Hokkaido/55/1996	320	80	40	80	80	1,280
A/duck/Hokkaido/1130/2001	160	80	40	<20	<20	1,280
A/duck/Hokkaido/1203/2001	160	80	80	<20	<20	640
A/duck/Mongolia/540/2001	80	160	40	<20	20	1,280
A/duck/Hokkaido/83/2004	160	80	40	<20	<20	640
A/duck/Hokkaido/W73/2007	80	80	80	<20	<20	640

ISSN: 1743-422X