Leukocyte migration-inhibition agarose test in swine after vaccination and challenge with inactivated and activated pseudorabies virus

Cell-mediated immunity to pseudorabies virus (PrV) was studied by means of the leukocyte migration-inhibition (LMI) agarose test. Migration of leukocytes from swine vaccinated with 10 TCID50 inactivate PrV and from normal control swine was not inhibited in the presence of specific PrV antigen. Cellular immune responses were detected in 80% of the vaccinated and 40% of the control group animals at the 1st week after challenge exposure. At the 2nd week, both groups of swine showed a peak level (p less than 0.001) immune response in the LMI test. This level of response remained until the 3rd week in the vaccinated group and the 2nd week in the control group. The averages of migration indices at the 1st, 2nd, 3rd and 4th weeks after challenge exposure were 0.74, 0.22, 0.60 and 0.89 in the vaccinated and 0.82, 0.29, 1.01 and 1.12 in the control group, respectively. Low concentrations of virus-neutralizing (VN) antibodies were present in 30% of the vaccinated swine at the 1st week, and 60% at the 2nd week after vaccination. Anamnestic antibody and primary VN antibody responses occurred after challenge in vaccinated and normal swine, respectively.