Clinical parameters monitored in experimental groups. (a) Clinical score, (b) Daily weight gain, (c) Rectal temperature and (d) Blood lymphocyte count. 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. Dotted line with white triangles: CP7_E2alf vaccinated group (CP7 vacc); dotted line with white squares: C-strain vaccinated group (C vacc); dotted line with white circles: control group; full line with black triangles: CP7_E2alf vaccinated and challenged group (CP7 vacc & chal); full line with black squares: C-strain vaccinated and challenged group (C vacc & chal); full line with black circles: infected group.