FIG. 2.

Mean (±SD) vaccine-specific lymphoproliferative responses determined by a colorimetric lymphocyte proliferation assay. Adult horses, 3-day-old foals, and 3-month-old foals were vaccinated with a killed adjuvanted vaccine twice with 3 weeks between administrations. PBMCs were collected from each animal prior to vaccination (baseline), 3 weeks after administration of the first dose and prior to administration of the second dose (dose 1), and 3 weeks after administration of the second dose (dose 2). Different numbers (1, 2, and 3) within an age group indicate significant differences between sample time points. Different letters (a, b, and c) within a time point indicate significant differences between age groups. Significance was set at a P value of <0.05.