Table 2. Amino acid differences in antigenic sites A‒E, Yokohama, 2016/17 and 2017/18 influenza seasons.
| Strain | Clade | Amino acid difference compared with A/Hong Kong/7127/2014 in the antigenic site | ||||
|---|---|---|---|---|---|---|
| A | B | C | D | E | ||
| A/Singapore/INFIMH-16–0019/2016 | 3C.2A1 | R142G | Null | Null | N121K, N171K | Null |
| A/Gunma/140/2017 | 3C.2A1a | N122D, T135K | Null | Null | N121K, N171K | G78D, Y94H |
| A/Osaka/163/2017 | 3C.2A1b | Nulla | Null | H311Q | N121K, N171K | K92R |
| A/Yokohama/1/2018 | 3C.2A1b | T135K, R142G | Null | H311Q | N121K, N171K | E62G, K92R |
| A/Yokohama/145/2017 | 3C.2A1b | T135N | Null | H311Q | N121K, N171K | K92R |
| A/Shimane/112/2017 | 3C.2A2 | T131K, R142K | Null | Null | A212T | R261Q |
| A/Yokohama/150/2017 | 3C.2A3 | T135K, S144K, R150K | Null | Null | N121K | Y94H |
| A/Yokohama/138/2017 | 3C.2A4 | R142G, S144R | Q197H | D53N | N171K | Null |
aNo mutation.