Table 2. Effect of mutations A222V and G228S of influenza A(H6N6) virus hemagglutinin on binding affinity to erythrocytes from various animalsa.
| Virus | Mean hemagglutination titerb |
|||
|---|---|---|---|---|
| Turkey | Chicken | Guinea pig | Horse | |
| Types of erythrocytes | ||||
| rgH6N6 × PR8-222V/228S | 32 | 32 | 32 | 32 |
| rgH6N6 × PR8-222A/228S | 32 | 32 | 16 | 32 |
| rgH6N6 × PR8-222V/228G | 32 | 64 | <2 | 2 |
| rgH6N6 × PR8-222A/228G | 32 | 64 | <2 | <2 |
| rgH6N6 × pdm09-222V/228S | 32 | 32 | 32 | 16 |
| rgH6N6 × pdm09-222A/228S | 32 | 32 | 32 | 32 |
| rgH6N6 × pdm09-222V/228G | 32 | 64 | <2 | <2 |
| rgH6N6 × pdm09-222A/228G | 32 | 128 | <2 | 2 |
rg indicates reverse genetics.
All virus concentrations were normalized to a hemagglutination titer of 32 in turkey erythrocytes. Each assay was repeated three times, and in each case, the standard deviation was 0.