Secretion of IL-1? and IL-10 by PBMC from HAV- and Sham-vaccinated animals. At the indicated time points post-MAP challenge PBMC were isolated from HAV-vaccinated (triangle) or Sham-vaccinated (grey square) calves and stimulated for 24 h with PPD-J or left unstimulated (control). Supernatants were assessed for the presence of A. IL-1? and B. IL-10 in triplicate by ELISA and concentrations of secreted cytokine were assessed relative to standard curve. The mean +/- SD PPD-J specific (PPD-J induced cytokine concentration ¿ unstimulated cytokine concentration) is shown for n = 6 (HAV-vaccinated) or n = 5 (Sham-vaccinated) animals including samples taken week -11, immediately prior prime vaccination; week -5, immediately prior boost vaccination; week 0, immediately prior to MAP challenge and up to 36 weeks post challenge. Significance between groups is indicated as * P < 0.05, ** P < 0.01.