Table 4.
ECTV-IL-4 recombinants expressing the highest levels of IL-4 cause lethal infections of Swiss and C57BL/6 mice immunized with the Dryvax™ smallpox vaccine.
| Challenge virus |
Strain | Dose of Dryvax™1 | |||
|---|---|---|---|---|---|
| 2×103 PFU/mouse | 2×104 PFU/mouse | ||||
| Mean time to death |
Mortality at 21 days p.i. (%) |
Mean time to death |
Mortality at 21 days p.i. (%) |
||
| -WT | Swiss | NA2 | 0/8 (0) | NA | 0/8 (0) |
| -7.5E-IL-4 | Swiss | 6 | 5/8 (63)3 | 7 | 1/8 (13)4 |
| -7.5E/L-IL-4 | Swiss | 6.6 ± 2.0 | 8/8 (100) 3 | 7.0 ± 0.9 | 8/8 (100)3 |
| -11KL-IL-4 | Swiss | 6.0 ± 0.08 | 8/8 (100) 3 | 6.4 ± 0.8 | 7/7 (100)3 |
| -WT | C57BL/6 | NA | 0/8 (0) | NA | 0/8 (0) |
| -7.5E-IL-4 | C57BL/6 | NA | 0/8 (0)4 | NA | 0/8 (0)4 |
| -7.5E/L-IL-4 | C57BL/6 | 7.4 ± 0.7 | 8/8 (100) 3 | 7.1 ± 0.8 | 8/8 (100)3 |
| -11KL-IL-4 | C57BL/6 | 7.4 ± 0.5 | 8/8 (100) 3 | 6.9 ± 0.4 | 8/8 (100)3 |
1
Swiss and C57BL/6 mice were infected with the indicated dose of Dryvax™ vaccine in the right-rear FP. Seven weeks later mice were challenged in the left-rear FP with the indicated viruses at 2×104 PFU/mouse.
2
NA – not applicable.
3
P<0.05 compared to ECTV-WT control.
4
P>0.05 compared to ECTV-WT control.