Agar gel diffusion precipitation and immunoelectrophoresis of the Aujeszky virus

: Two virulent and two vaccinal virus strains are dealt with. The study has been carried out by means of the diffusion precipitation reaction in agar gel and the immunoelectrophoresis technique using hyperimmune sera obtained from cocks as well as concentrated and purified antigens. It has been demonstrated that the virulent and the vaccinal (latent) strains of Aujeszky's disease virus cannot be differentiated serologically. The complex of antibodies induced by the virulent and the latent strains has proved to contain absolutely identical products. On the basis of the results obtained it is suggested to find some other means (markers) to differentiate the virulent from the latent strains of the virus.