Potency analysis of inactivated vaccines for Aujeszky's disease virus (ADV), strain RC/79: lymphocyte stimulation in immunized pigs.

Mitogenic and antigenic lymphocyte stimulation was examined in pigs that had been immunized with 2 inactivated vaccines which had been prepared with Aujesky's disease virus (ADV), strain RC/79. One vaccine was partially purified by ultra-centrifugation (Vaccine A) the other one was not (Vaccine B). A second dose of vaccine had no influence over the blastogenic response when the lymphocytes were stimulated with phytohemoagglutinin (PHA). Lymphocyte response to the ADV antigen in the immunized pigs was significantly higher at day 30 post inoculation than at day 0 indicating that it was highly specific. Cellular antigens contained in the viral cultures produced a slight non-specific response as shown by a low increase in the levels of lymphocyte blastic transformation (LBT) in the control group at day 30 p.i., this group only received a non infected Vero cell suspension. This was the case in pigs that received vaccine A as well as in those that were vaccinated with vaccine B. Vaccine B contains a greater quantity of contaminating cellular antigens, since it is an impure vaccine. Such antigens could act as non-specific immunomodulators, potentiating cell-mediated immunity (CMI). This assay demonstrated that inactivated vaccines produced with VPR-RC/79, partially purified and unpurified are capable of inducing a humoral immune response. The blastogenic reaction of the peripheral blood lymphocytes to antigens of ADV strain RC/79, indicated that the employed immunogens also induced the CMI. Results indicate that the analyzed immunogens could be considered for the possible implementation of epidemiological measures, which imply the use of vaccines to prevent pseudo-rabies in Argentina.