Table 1. Summery of the reassortment events in swine influenza A viruses.
| Year | Strain | Subtype | PB2 | PB1 | PA | HA | NP | NA | MP | NS | Ref. |
| 1976 | A/swine/Iowa/1/1976 | H1N1 | S1 | S2 | S1 | S1 | S1 | S1 | S1 | S1 | |
| 1976 | A/swine/Tennessee/15/1976 | H1N1 | S1 | S2 | S1 | S1 | S1 | S1 | S1 | S1 | |
| 1976 | A/swine/Tennessee/19/1976 | H1N1 | S1 | S1 | S1 | S1 | S1 | S1 | S2 | S1 | |
| 1976 | A/swine/Tennessee/23/1976 | H1N1 | S1 | S2 | S1 | S1 | S1 | S1 | S1 | S1 | |
| 1977 | A/swine/Tennessee/48/1977 | H1N1 | S1 | S1 | S2 | S1 | S1 | S1 | S2 | S1 | |
| 1977 | A/swine/Tennessee/61/1977 | H1N1 | S1 | S1 | S1 | S1 | S1 | S1 | S2 | S1 | |
| 1977 | A/swine/Tennessee/62/1977 | H1N1 | S1 | S1 | S1 | S1 | S1 | S2 | S2 | S1 | |
| 1977 | A/swine/Tennessee/64/1977 | H1N1 | S1 | S2 | S1 | S1 | S1 | S1 | S1 | S1 | |
| 1977 | A/swine/Tennessee/82/1977 | H1N1 | S1 | S1 | S1 | S2 | S1 | S2 | S1 | S1 | |
| 1977 | A/swine/Tennessee/96/1977 | H1N1 | S1 | S1 | S1 | S1 | S1 | S1 | S1 | S2 | |
| 1979 | A/swine/Minnesota/5892-7/1979 | H1N1 | S1 | S1 | S1 | S1 | S2 | S1 | S1 | S1 | |
| 1981 | A/swine/Ontario/6/1981 | H1N1 | S1 | S1 | S1 | S1 | S2 | S1 | S1 | S1 | |
| 1986 | A/swine/Iowa/1/1986 | H1N1 | S1 | S1 | S2 | S2 | S1 | S1 | S1 | S1 | |
| 1988 | A/swine/Wisconsin/1915/1988 | H1N1 | S1 | S1 | S1 | S1 | S2 | S1 | S1 | S1 | |
| 2004 | A/swine/Korea/CAN01/2004 | H1N1 | S1 | S1 | S1 | S1 | S1 | S2 | S1 | S1 | [25] |
| 2004 | A/swine/Spain/53207/2004 | H1N1 | S1 | S1 | S1 | S2 | S1 | S2 | S1 | S3 | |
| 2007 | A/swine/Ohio/24366/07 | H1N1 | S1 | S1 | S1 | S2 | S1 | S2 | S1 | S1 | |
| 1998 | A/swine/Italy/1521/98 | H1N2 | S1 | S1 | S1 | S2 | S1 | S3 | S1 | S1 | [18] |
| 1999 | A/Swine/Indiana/9K035/99 | H1N2 | S1 | S1 | S1 | S2 | S1 | S1 | S1 | S1 | [36] |
| 2000 | A/Swine/Minnesota/55551/00 | H1N2 | S1 | S1 | S1 | S2 | S1 | S1 | S1 | S1 | [37] |
| 2004 | A/swine/Zhejiang/1/2004 | H1N2 | S1 | S1 | S1 | S1 | S1 | H | S1 | S1 | [19] |
| 2005 | A/swine/Cloppenburg/IDT4777/2005 | H1N2 | S1 | S1 | S1 | S1 | S1 | S2 | S1 | S1 | [20] |
| 2006 | A/swine/Miyazaki/1/2006 | H1N2 | S1 | S1 | S1 | S1 | S1 | S3 | S1 | S1 | [21] |
| 2007 | A/swine/Shanghai/1/2007 | H1N2 | S1 | S1 | S1 | S2 | S1 | S1 | S1 | S1 | |
| 1998 | A/Swine/Nebraska/209/98 | H3N2 | A | H | A | H | S | H | S | S | [36] |
| 2001 | A/swine/Spain/33601/2001 | H3N2 | S1 | S1 | S1 | S2 | S1 | S2 | S1 | S1 | |
| 2003 | A/swine/North Carolina/2003 | H3N2 | S | S | S | H1 | S | H2 | S | S | |
| 2007 | A/swine/Korea/CY04/2007 | H3N2 | S1 | S1 | S1 | S1 | S1 | S1 | S1 | S2 | [25] |
| 2007 | A/swine/Korea/CY07/2007 | H3N2 | S1 | S1 | S2 | S2 | S1 | S1 | S1 | S1 | [25] |
| Incompletely sequenced strains | |||||||||||
| 1998 | A/swine/North Carolina/35922/98 | H3N2 | S | H | S | H | S | H | S | S | [16] |
| 2004 | A/swine/MI/PU243/04 | H3N1 | S1 | S1 | S1 | S1 | S1 | S2 | S1 | S1 | [38] |
| 2006 | A/swine/Missouri/2124514/2006 | H2N3 | S1 | S2 | A | A | S1 | A | S1 | S1 | [39] |
| Anomalous strains [31] | |||||||||||
| 2003 | A/swine/Alberta/56626/03 | H1N1 | S1 | S1 | S2 | S1 | S1 | S3 | S1 | S1 | [40] |
| 2003 | A/swine/Ontario/53518/03 | H1N1 | S3 | S3 | S2 | S1 | S3 | S1 | S1 | S1 | [40] |
| 2003 | A/swine/Ontario/57561/03 | H1N1 | S1 | S1 | S2 | S1 | S3 | S1 | S2 | S1 | [40] |
| 2004 | A/swine/Ontario/48235/04 | H1N2 | S1 | H1 | S1 | H2 | S2 | H3 | S3 | S3 | [40] |
| 2004 | A/swine/Ontario/11112/04 | H1N1 | S1 | H | S1 | S1 | S2 | S1 | S1 | S1 | [40] |
| 2005 | A/swine/Alberta/14722/2005 | H3N2 | S | S | S | S | S | H | S | S | [41] |
Footnote: The notation is S: swine, A: avian, and H: human. The numbers distinguish different host lineages. The strains listed as anomalous are either “frozen in time” or show evidence of homologous recombination [31].