Table 4.
Comparison of clinical signs presentation on CAST/EiJ mice infected with different doses of Variola virus during Phase 2 (animals challenged at 5–6 weeks of age).
| Dosage | 5 × 103* | 5 × 104* | 5 × 105* | 5 × 106* |
|---|---|---|---|---|
| Reduce grooming/pruritus onset (number of animals) | Day 15 pi (3/5) | Day 7 pi (3/5) | Day 7 pi (5/5) | Day 7 pi (5/5) |
| Oral/nasal erythema (number of animals) | NO | Day 7 pi (3/5) | Day 7 pi (2/5) | Day 7 pi (3/5) |
| Respiratory distress under anesthesia (number of animals) | NO | NO | Day 9 pi (4/5) | Day 9 pi (3/5) |
| Ocular discharge (number of animals) | Day 9 pi (1/5) | Day 7 pi (2/5) | Day 7 pi (3/5) | Day 7 pi (3/5) |
| Rear paw/tail skin lesions (number of animals) | NO | NO | Day 8 pi (2/5) | Day 9 pi (2/5)NP |
| Completed recovery | Day 17 pi | Day 19 pi | Day 19 pi | Day 19 pi |
Mice from gamma irradiated VARV and vehicle (PBS + .05% BSA) groups did not show any clinical signs mentioned above.
pi = days post inoculation.
NO = Never observed.
NP = Negative by real time PCR.
*
Challenged groups, in plaque forming units (pfu).