Patent ID: 7361357

Claim:
A vaccine comprising at least two live mutant viruses, of the same family, wherein each virus contains a mutation in the viral genome, and the mutations in the viruses reside in the same genomic site such that the mutant viruses cannot recombine with each other to eliminate the mutations, and wherein two of the live mutant viruses consist of a mutant Bovine Viral Diarrhea Virus Type 1 (BVDV-1) and a mutant Bovine Viral Diarrhea Virus Type 2 (BVDV-2), wherein the BVDV-1 and the BVDV-2 comprise a mutation comprising an insertion of a heterologous sequence in the NS2-3 region that results in a cytopathic biotype, wherein said heterologous sequence is inserted at 3′ of nucleotide #4993 of the BVDV-1 genome, and at 3′ of nucleotide #4993 of the BVDV-2 genome.