FIG 2.

Time course of geometric mean TNA levels (NF₅₀) by group as determined by cell-based neutralization assay. All animals received the initial vaccination on study day 0. Groups receiving a second vaccination (groups 5, 6, and 7) had vaccine administered on study day 28. Values less than the limit of quantification (0.086 NF₅₀) were assigned a value of 0.043. Error bars, 95% confidence interval of the geometric means; arrows, times of vaccination (v) and challenge (c). The reference serum (BMI526) used for this assay is a pool of immune human sera with a mean ED₅₀ of 673.09 and an assay acceptance range of 375 to 971.