TABLE 3.
Polymorphism analysis of HA residues 125, 151, and 217, individually or in combinations, from 1 January 2013 to 1 September 2019
| Period | % (no.) of sequence with the indicated HA mutation(s)a
|
||||||
|---|---|---|---|---|---|---|---|
| A125T | A151T | L217Q | A125T+A151T | A125T+L217Q | A151T+L217Q | A125+A151T+L217Q | |
| 1 Jan. 2013 to 1 Sept. 2013 | 0 | 0 | 13.5 (28) | 0 | 0 | 0 | 0 |
| 1 Sept. 2013 to 1 Sept. 2014 | 0.9 (6) | 0.6 (4) | 1.6 (11) | 0 | 0 | 0 | 0 |
| 1 Sept. 2014 to 1 Sept. 2015 | 0 | 0.4 (1) | 3.9 (10) | 0 | 0 | 0 | 0 |
| 1 Sept. 2015 to 1 Sept. 2016 | 0 | 0 | 1.2 (1) | 0 | 0 | 0 | 0 |
| 1 Sept. 2016 to 1 Sept. 2017 | 0 | 1.2 (8) | 14.1 (94) | 0 | 0 | 0.15 (1) | 0 |
| 1 Sept. 2017 to 1 Sept. 2018 | 0 | 0 | 73.7 (14) | 0 | 0 | 5.3 (1) | 0 |
| 1 Sept. 2018 to 1 Sept. 2019 | 0 | 0 | 0 | 0 | 0 | 18.8 (3) | 68.8 (11) |
All available H7N9 virus sequences were retrieved from the Global Initiative on Sharing All Influenza Data (GISAID) from 1 January 2013 to 1 September 2019 in China (1 January 2013 to 1 September 2013 [sequence number = 208], 1 September 2013 to 1 September 2014 [sequence number = 700], 1 September 2014 to 1 September 2015 [sequence number = 258], 1 September 2015 to 1 September 2016 [sequence number = 85], 1 September 2016 to 1 September 2017 [sequence number = 666], 1 September 2017 to 1 September 2018 [sequence number = 19], and 1 September 2018 to 1 September 2019 [sequence number = 16]). The number in the bracket shows the number of sequences that contain the indicated mutations.