Table 3.
Presence ( +) or absence (-) of important amino acid substitutions or deletion (Δ).
| Substitution or deletion | Iso: | EU H1av | EU H1hu | H1pdm09 | EU H1hu | ||
|---|---|---|---|---|---|---|---|
| Ref: | EU H1av | EU H1hu | H1pdm09 | Past hu | Recent hu | US H1δ | |
| R43L | – | – | – | – | + | + /− (16) | |
| F/L71I | + /− *(11) | – | – | – | + * | + * | |
| Δ130 | – | – | – | – | – | – | |
| K141E | – | + /− (1) | – | + /− (1) | + | + | |
| E153K | – | + /− (1) | – | + /− (1) | – | – | |
| E155G | + /− (13) | – | + /− (1) | – | – | – | |
| N156D | – | – | + /− (1) | – | – | – | |
| D187N/S | – | – | + /− (3) | – | + | + | |
| S271P | – | – | + /− (1) | – | + | + | |
Isolates of each lineage were compared with reference viruses belonging to the same lineage. Isolates belonging to the EU H1hu lineage were also compared with the US H1δ and past (TW86) and recent (NC99, BR07) human seasonal reference viruses due to their common origin. The symbol + /− is used where some isolates in the same lineage have the substitution while others do not. The number of isolates with the substitution are shown in brackets. In total, there were 42 EU H1av HA sequences, 21 EU H1hu and 5 H1pdm09 HA sequences.
Iso—isolates, Ref—reference viruses, hu—human viruses.
The asterisks denote a different substitution; L71L for EU H1av and I71F for the EU H1hu isolates when compared to the US H1δ and the recent human reference viruses.