Figure 2

Survival rates of passively immunized mice and control. Four groups of mice (n = 10/group) were passively immunized with serum with NAT titers of 2.62 (□/sky blue, group 1), 2.09 (x/dark blue, group 2), 1.65 (○/navy blue, group 3) and 1.01 log10 (●/pale blue, group 4). The NATs from the passively immunized mice are shown in Table 2. The control group (■/red, n = 10) was left untreated. Twenty-four hours after serum administration, both the immunized and the control groups of mice were challenged with WNV NY99, and their survival was observed for 21 days thereafter. All of the passively immunized mice in groups 1, 2 and 3 survived. P values were calculated using Dunnett-Hsu multiple comparison test. *P <0.05.