Table 1. Amino acid differences between NC/02 and other North American swine H1 influenza viruses from 1930 to 2008.
| Virus name | Amino acid change* | Accession number | Subtype |
|---|---|---|---|
| A/swine/IL/00685/2005 | R → N | ACM17276 | H1N1 |
| A/swine/Kentucky/SG1167/2003 | R → I | AHB51196 | H1N1 |
| A/swine/Minnesota/07002083/2007 | R → N | ACL79904 | H1N1 |
| A/swine/Wisconsin/464/98 | R → Q | AAF87284 | H1N1 |
| A/swine/Iowa/46519-4/2008 | R → Y | ADO34923 | H1N1 |
*Presence of other amino acids at position 149 (H3 numbering) in 398 full-length HA sequences of pre 2009 (from 1930 to 2008) North American swine H1 influenza.