From: Conserved amino acid markers from past influenza pandemic strains
Initial strain | Region | Shift | Drift |
---|---|---|---|
H1N1 swine | Henan/Tianjin | H5, N1 | 199 PB2 117 NS1 |
H1N1 human | New Zealand | H9, N2 | 211 PB1 |
 | Australia | H7, N2 | 117 NS1 |
 | U.S.A., Asia | H5, N1 | (one or both) |