Figure 8. Virulence of different VACV strains after infection of ISG15+/+ and ISG15−/− mice.
A. Mice were inoculated i.n with purified WR (105 or 5×106 PFU/mouse) or VVΔE3L (5×107 PFU/mouse) or VVE3LΔ83N (5×107 PFU/mouse) or VVE3LΔ26C (5×107 PFU/mouse). Mice were individually weighed daily, and mean percentage weight loss of each group (n = 8) was compared with weight immediately prior to infection. B. Survival rate after i.n inoculation as described in A. Dead animals were scored daily and represented as the percentage of surviving animals. P≤0.01 in all experiments. C. Mice were inoculated as described above and for each individual signs of illness such as ruffled fur and lack of activity were monitored with time and are given in arbitrary units. P≤0.01 in all experiments.