|
Challenge virus
|
Challenge time pv
|
Vaccine
|
Virus isolation from the swabs (shedding/total log
10
EID
50
/mL)
|
No. surviving/total
|
|---|
|
Day 3 pc
|
Day 5 pc
|
Day 7 pc
|
|---|
|
Oropharyngeal
|
Cloacal
|
Oropharyngeal
|
Cloacal
|
Oropharyngeal
|
Cloacal
|
|---|
|
XN/07
|
1 week
|
C-KCE-HA
|
0/7
|
0/7
|
0/7
|
0/7
|
0/7
|
0/7
|
7/7
|
|
C-KCE
|
7/7(3.1 ± 0.6)
|
5/7(2.4 ± 0.5)
|
—
|
—
|
—
|
—
|
0/7
|
|
PBS
|
7/7(4.2 ± 0.5)
|
6/7(3.8 ± 0.4)
|
—
|
—
|
—
|
—
|
0/7
|
|
3 weeks
|
C-KCE-HA
|
0/7
|
0/7
|
0/7
|
0/7
|
0/7
|
0/7
|
7/7
|
|
C-KCE
|
7/7(2.7 ± 0.6)
|
6/7(2.4 ± 0.6)
|
—
|
—
|
—
|
—
|
0/7
|
|
PBS
|
7/7(4.3 ± 0.7)
|
7/7(4.3 ± 0.7)
|
—
|
—
|
—
|
—
|
0/7
|
|
12 weeks
|
C-KCE-HA
|
0/7
|
0/7
|
0/7
|
0/7
|
0/7
|
0/7
|
7/7
|
|
C-KCE
|
7/7(2.7 ± 0.7)
|
7/7(2.6 ± 1.1)
|
—
|
—
|
—
|
—
|
0/7
|
|
PBS
|
7/7(2.1 ± 0.9)
|
4/7(1.8 ± 1.2)
|
—
|
—
|
—
|
—
|
0/7
|
|
36 weeks
|
C-KCE-HA
|
0/7
|
0/7
|
0/7
|
0/7
|
0/7
|
0/7
|
7/7
|
|
C-KCE
|
7/7(3.1 ± 0.3)
|
6/7(2.1 ± 0.5)
|
—
|
—
|
—
|
—
|
0/7
|
|
PBS
|
7/7(2.7 ± 0.7)
|
7/7(1.8 ± 0.6)
|
—
|
—
|
—
|
—
|
0/7
|
- One-month-old SPF ducks were used in these studies. Groups of seven ducks were inoculated subcutaneously with 105 PFU of C-KCE-HA, 105 PFU of C-KCE or with PBS as a control. They then were challenged intramuscularly with 100-fold DLD50 homologous (XN/07) AIVs at 1 week, 3 weeks, 12 weeks or 24 weeks post-vaccination (pv). Oropharyngeal and cloacal swabs were collected on days 3, 5, and 7 post-challenge (pc) and titrated in SPF eggs. All of the ducks in C-KCE and PBS groups died within 5 days. The horizontal line indicates that the animals had died by that time point.
