An immunogenic composition comprises (1) an LHRH-diphtheria toxoid conjugate, and (2) an immunostimulating complex that itself optionally includes an additional protein, but the composition does not contain an ionic polysaccharide as adjuvant. The composition is for use in a method of eliciting in an animal an effective immune response. The immune response may inhibit the reproductive capacity of the animal. It is further provided a vaccine against bovine viral diarrhea virus (BVDV) comprising as adjuvant a combination of DEAE-dextran and an immunostimulating complex (ISCOM).
