Evaluation of immunity to Aujeszky's disease virus

The authors studied the immune response of vaccinated and unvaccinated pigs to challenge infection with Aujeszky's disease virus. One group re­ ceived a live vaccine by the nasal route, a second group was inoculated intra­ muscularly with inactivated vaccine, and a third group served as unvaccinated controls. General and local immune responses were measured by indirect ELISA, serum neutralisation, antibody-dependent cellular cytotoxicity assay, and complement-dependent antibody lysis. Weight gain was chosen as the quantitative criterion for the clinical consequences of experimental infection. A discussion of the results considers the limitations of in vitro tests as reflections of the degree of immune protection occurring in vivo. In general, nasal vaccination conferred a better immunity to experimental infection than parenteral vaccination.