Figure 6个  Table 4个
    • 2016.6–2017.5 2017.6–2018.5 2018.6–2019.5 Total P value
      Received samples (n) 4983 16, 625 23, 130 44, 738
      Influenza type A B A + B A B A + B A B A + B A B A + B
      Age 741 (14.9) 213 (4.7) 16 (0.3) 2617 (15.7) 1332 (8.0) 60 (0.4) 3575 (15.5) 1202 (5.2) 58 (0.3) 6933 (15.5) 2747 (6.1) 134 (0.3)
        < 2 years 25 (3.4) 4 (1.9) 1 (6.3) 131 (5.0) 36 (2.7) 2 (3.3) 295 (8.3) 74 (6.2) 5 (8.6) 451 (6.5) 114 (4.2) 8 (6.0) P < 0.0001
       2–4 years 286 (38.6) 64 (30.1) 7 (43.8) 991 (37.9) 331 (24.9) 21 (35.0) 1231 (34.4) 221 (18.4) 19 (32.8) 2508 (36.2) 616 (22.4) 47 (35.1)
       5–14 years 372 (50.2) 131 (60.5) 7 (43.8) 889 (34.0) 696 (52.3) 31 (51.7) 1316 (36.8) 573 (47.7) 30 (51.7) 2577 (37.2) 1400 (51.0) 68 (50.8)
       15–64 years 56 (7.6) 14 (6.6) 0 (0.0) 568 (21.7) 240 (18.0) 3 (5.0) 686 (19.2) 311 (25.9) 4 (6.9) 1310 (18.9) 565 (20.6) 7 (5.2)
        > 64 years 2 (0.3) 0 (0.0) 0 (0.0) 38 (1.5) 29 (2.2) 3 (5.0) 47 (1.3) 23 (1.9) 0 (0.0) 87 (1.3) 52 (1.9) 3 (2.2)
      A + B: Co-infection with FLUAV and FLUBV.
      P < 0.0001: Differences in the distribution by age groups were found between FLUAV and FLUBV.

      Table 1.  Prevalence of FLUV in Wuhan city, Hubei province, China during 2016–2019.

    • Type Year Clade No. of strain Vaccine strain % identity of HA
      Nucleotide Amino acid
      A/H3N2 2017 3c.2a2 3 A/Hong Kong/4801/2014 98.9–99.9 98.8–100
      2018 3c.2a2, 3c.2a1b 4 A/Singapore/INFIMH-16-0019/2016 98.3–99.8 98.1–99.8
      2019 3c.2a1b 5 A/Kansas/14/2017 96.3–100 96.5–99.9
      A/H1N1 2018 6b.1 6 A/Michigan/45/2015 98.4–99.7 98.9–99.8
      2019 6b.1 5 A/Brisbane/02/2018 98.0–98.9 98.1–98.9
      B/Yamagata 2018 3 3 B/Phuket/3073/2013 98.4–99.9 99.5–99.8
      2019 3 2 B/Phuket/3073/2013 98.4–99.9 99.1–99.7

      Table 2.  Comparison of nucleotide and amino acid similarities between the vaccine and the circulating seasonal influenza strains in Wuhan city, Hubei province, China.

    • Year Vaccine strain No. of strain Dominant epitope Differing Residues pepitope Efficacy Vaccine efficacy (47%) Vaccine efficacy (100%)
      2017 A/Hong Kong/4801/2014 3 A 131, 142 0.1053 0.2099 20.99 44.66
      2018 A/Singapore/INFIMH-16-0019/2016 2 A 131, 142, 171 0.1579 0.0800 8.00 17.02
      1 A 135, 142 0.1053 0.2099 20.99 44.66
      1 A 135 0.0526 0.3401 34.01 72.34
      2019 A/Kansas/14/2017 5 A 131, 138, 144 0.1579 0.0800 8.00 17.02

      Table 3.  Efficacy among the vaccine strains and number of mutations found on the dominant epitope of A(H3N2) isolated in Wuhan city, Hubei province, China.

    • Year Vaccine strain No. of strain Dominant epitope Differing Residues pepitope Efficacy Vaccine efficacy (53%) Vaccine efficacy (100%)
      2018 A/Michigan/45/ 2015 2 C 38, 295 0.0606 0.4579 45.79 86.40
      2 B 183 0.0455 0.4759 47.59 89.79
      1 C 295 0.0303 0.4939 49.39 93.19
      1 D 164, 173 0.0417 0.4804 48.04 90.64
      2019 A/Brisbane/02/ 2018 3 C 45, 298 0.0606 0.4579 45.79 86.40
      1 C 45, 298, 302 0.0909 0.4218 42.18 79.59
      1 B 160, 185 0.0909 0.4218 42.18 79.59

      Table 4.  Efficacy among the vaccine strains and number of mutations found on the dominant epitope of A(H1N1)pdm09 isolated in Wuhan city, Hubei province, China.