Figure 6: Memory humoral and mucosal immune responses were induced in piglets immunized with the PTSL vaccine.

Sera were collected from three randomly selected surviving piglets from each group on the 8^th dpc (n = 3). Anal swabs were collected on the 24^th dpc, from the two surviving piglets of the unvaccinated control group (n = 2), three randomly selected piglets of the PO and IM group (n = 3). Bile and intestines were collected from the two surviving piglets of the unvaccinated control group, two randomly selected piglets of the PO group, and the two protected piglets of the IM group (n = 2), and processed at necropsy on the 33^rd dpc. IgG in serum (A), fecal IgA (B) and IgA in bile and intestinal mucosa (C) were determined by indirect ELISA. *p < 0.05, **p < 0.01.