IL-10 gene expression assessed using real-time RT-PCR in blood from experimental groups. The values presented are the relative expressions calculated from the Ct results on D3, D5 and D12 post-infection (respectively D5, D7 and D14 post-vaccination), in relation to D0 as described in Materials and Methods. All data are reported as the mean (± SE) of results obtained for the 5 pigs in each group. *p < 0.05 compared each post-vaccination, post-challenge or post-infection value with the respective control value using the Mann–Whitney test. CP7 vacc: CP7_E2alf vaccinated; C vacc: C-strain vaccinated; CP7 vacc & chal: CP7_E2alf vaccinated and challenged; C vacc & chal: C-strain vaccinated and challenged.