Figure 4.

Specific anti-VP4 IgG in serum response after oral immunization. Mice were orally immunized with 10⁹ CFU of pNZ8112-VP4/NZ9000 and pNZ8112-VP4/NZ9000, and the immune protocol was administered on three consecutive days: the inoculation at days 0, 1, and 2; a booster at days 14, 15, and 16; a second booster at days 28, 29, and 30. Mice sera were collected on days 0, 9, 25, and 41 following the first immunization. Sera samples were analyzed for the presence of IgG-specific VP4 antibodies by ELISA. The OD value of each well represents a mixture of two serum samples; the bars represent IgG mean OD values in four wells representative of eight samples, which were detected at different time points for each group.