Lymphocytes and monocytes cell counts. Mean monocytes (A and B) and lymphocytes (C and D) cell counts in non-vaccinated (A and C) and vaccinated animals (B and D), expressed as 109 cells/L. dpi: day post-infection. For a better readability error bars were removed. *P < 0.05; **P < 0.01 and ***P < 0.001 between vaccinated and non-vaccinated groups infected with the same serotype. #P < 0.05; ##P < 0.01; ###P < 0.001 compared to the control group.