Table 1.

Distances between genes of A/California/04/2009 (H1N1) and those of the closest H1N2 isolates.

		PB21	PB1	PA	HA	NP	NS3
A/swine/Indiana/P12439/2000		0.0368*2	0.0430	0.0474	0.0525	0.0360*	0.0533
A/swine/Indiana/9K035/1999		0.0406	0.0395*	0.0498	0.0513*	0.0387	0.0439
A/swine/Minnesota/55551/2000		0.0372	0.0451	0.0450*	0.1224	0.0408	0.0427*
A/swine/Illinois/100084/2001		0.0446	0.0434	0.0451	0.0597	0.0404	0.0528
A/swine/Illinois/100085A/2001		0.0453	0.0420	0.0486	0.0578	0.0404	0.0539

¹ Genes: PB2, PB1 and PA, polymerase genes; HA, haemagglutinin; NP, nucleoprotein; NS, non-structural proteins 1 and 2

² Patristic distances; nucleotide substitutions/site. The isolate that gave the shortest distance for each gene is marked with an asterisk.

³ All five NS1 genes encode a slightly truncated (219 amino acids) NS1 protein as does the NS1 gene of S-OIV.