Fig. 1.

Course of the virus-specific lymphocyte proliferative responses represented by SI for mononuclear cells from mesenteric lymph nodes, spleen and blood from pigs after inoculation with virulent (group 1) or attenuated (group 2) PEDV or mock-inoculation (group 3) and after challenge with virulent PEDV. The SI are the mean cpm of virus-specific stimulated wells versus mean cpm of control antigen stimulated wells, being cpm counts per minute. The mean value of the SI obtained from the group of unexposed pigs is represented by a line crossing the Y-axis. Statistically significant differences (P≤0.05) with values obtained in nonexposed pigs are noted as *. Differences between groups are nodded as: ‘a’ when differences are between groups 1 and 2, ‘b’ between groups 1 and 3 and ‘c’ for differences between groups 2 and 3.