Figure 7个  Table 4个
    • Group Generation of vaccinated strain Vaccination dose Generation of the challenge strain Challenge day Challenge dose
      1 p95 103.5 EID50 p5 25 104.5 EID50
      2 p95 104.5 EID50 p5 25 104.5 EID50
      3 p105 103.5 EID50 p5 25 104.5 EID50
      4 p105 104.5 EID50 p5 25 104.5 EID50
      5 – – p5 25 104.5 EID50
      6 – – – – –

      Table 1.  Specific grouping for evaluation of vaccine effectiveness.

    • Group Generation/Vaccination dose Morbidity Mortality
      1 p5/104.5 EID50 10/10 7/10
      2 p70/104.5 EID50 5/10 3/10
      3 p80/104.5 EID50 3/10 3/10
      4 p80/103.5 EID50 3/10 0/10
      5 p95/103.5 EID50 2/10 0/10
      6 p95/104.5 EID50 2/10 0/10
      7 p105/103.5 EID50 2/10 0/10
      8 p105/104.5 EID50 2/10 0/10
      Negative control – 0/10 0/10

      Table 2.  The morbidity and mortality of chickens after vaccination of CK/CH/GD/GZ14 strain of different generation.

    • Group Generation of vaccinated strain Vaccinated dose Generation of the challenge strain Anatomy results Morbidity (n = 10 in each group) Protection rate
      1 p105 103.5 EID50 p5 1 chicken showed mild kidney enlargement and 1 chicken showed kidney enlargement 2/10 80%
      2 p105 104.5 EID50 p5 1 chicken showed mild kidney enlargement, 1 chicken showed kidney enlargement and yolk malabsorption 2/10 80%
      3 p95 103.5 EID50 p5 2 chickens showed kidney enlargement 2/10 80%
      4 p95 104.5 EID50 p5 2 chickens showed kidney enlargement 2/10 80%
      5 – – p5 10 chickens showed kidney enlargement and urate deposition 10/10 0
      6 – – – The kidneys of all chickens were normal 0 –

      Table 3.  Protective efficacy of the attenuated virus CK/CH/GD/GZ14 of different generation to 10-day-old SPF chickens against challenge with the CK/CH/GD/GZ14 virus of the 5th generation.

    • Gene Nucleotide position p5–p50 p50–p80 p80–p95 p95–p105 p105–p120 Amino acid position Amino acid insertion and replacement
      5'-UTR 16 – insert A – – – – –
      5'-UTR 18 – A → T – – – – –
      5'-UTR 21 – deletion T – – – – –
      1a 2854 G → T – – – – 957 V → F
      1a 3625 G → T – – – – 1209 A → S
      1a 6844 – T → C – – – 2249 W → R
      1a 7471 T → C – – – – 2491 Y → H
      1a 8280 A → G – – – – 2707 Q → R
      1a 10, 498 C → A – – – – 3500 Q → K
      1a 11, 457 T → A – – – – 3820 Silent
      1a 11, 786 C → T – – – – 3929 A → V
      1b 1414 – G → T – – – 423 A → S
      E 209 – – G → T – – 70 R → I
      S1 353 C → T – – – – 118 P → L
      S1 535 – A → G – – – 179 T → A
      S1 1159 – G → T – – – 387 V → F
      S1 1232 – G → T – – – 411 R → L
      S2 665 – – – C → T – 222 A → V
      S2 1034 C → T – – – – 345 S → F
      S2 1403 C → T – – – – 468 S → F
      5a 94 – – G → A – – 32 E → K
      N 434 – – C → T – – 145 P → L
      N 1207 G → C – – – – 403 A → P

      Table 4.  Summary of nucleotide and amino acid mutations during CK/CH/GD/GZ14 passage.