Table 3. Amino acid (AA) similarity matrix for strains of a particular subtype used to infect SPF chickens of group 2 (in bold) versus PA-antigens per HA-type (table 1).
| H5N2 | 100.00 | ||||
| H5.07 | 97.37 | 100.00 | |||
| H5.02 | 96.15 | 96.42 | 100.00 | ||
| H5.97 | 95.75 | 95.39 | 93.52 | 100.00 | |
| H5.06 | 95.29 | 95.45 | 94.21 | 97.48 | 100.00 |
| H6N2 | 100.00 | ||||
| H6.07 | 96.01 | 100.00 | |||
| H7N1 | 100 | ||||
| H7.03 | 97.11 | 100.00 | |||
| H9N2 | 100.00 | ||||
| H9.99 | 97.49 | 100.00 | |||
| H9.07 | 94.39 | 93.77 | 100.00 |
Similarity was calculated based on the HA1 part of the hemagglutinin (sequence length 318 AA). Percentages in bold and italics denote similarity between strains used for infection versus corresponding PA-antigen.