Anti-idiotypic antibodies (anti-Id or Ab2) were generated in Balb/c mice against either mouse monoclonal or swine polyclonal antibodies (Abl) to pseudorabies virus (PRV) antigens by conventional and sequential immunization methods. In the conventional method, one antibody preparation was repeatedly injected into the animals, whereas three anti-PRV antibody preparations were used alternately for the sequential immunization procedure. Anti-Ids were serologically characterized for possession of the Ab2s that detect shared idiotype (IdX) on antibodies to PRV antigens. Only the Ab2s that were generated by the sequential immunization method recognized the IdX present on murine and swine antibodies to PRV. The sequential immunization method described herein was anticipated to be helpful for generating virus specific Ab2s as candidates for serodiagnostic reagents or vaccines.