Figure 1

Survival rate of WN-VAX immunized mice and control. Five groups of mice (n = 10/group) were immunized twice with 0.313 (□/black), 0.078 (x/pale blue), 0.02 (▲/blue gray), 0.005 (●/sky blue) and 0.001 (○/light purple) μg/dose of WN-VAX at an interval of seven days. The control group (■/red, n = 10) was left untreated. Seven days after the second immunization, both the immunized and the control groups of mice were challenged with WNV NY99, and their survival was observed for 21 days thereafter. The survival rate increased correspondingly with an increase in the concentration of WN-VAX. P values were calculated using the Dunnett-Hsu multiple comparison test. The arithmetic means of survival time for the groups of mice immunized with 0.313, 0.078, 0.02, 0.005 and 0.001 μg/dose of WN-VAX were 21.0., 21.0, 18.8, 17.3 and 11.1 days. *P <0.05.