Patent ID: 7763428

Claim:
A method of vaccinating against PRRSV comprising: administering to a subject a sequence comprising a heterodimer of a matrix protein (M protein) of porcine reproductive and respiratory syndrome virus (PRRSV) and a glycoprotein 5 (GP5) of PRRSV, wherein the GP5 protein is linked to the M protein by a disulfide bond, wherein the disulfide bond results from a bond between a cysteine amino acid in the M protein located at position 9 in North American PRRSV strains, wherein the position number 9 is determined from sequence alignment with the amino acid sequence of SEQ ID NO:28, or at position 8 in EU PRRSV strains, wherein the position number 8 is determined from sequence alignment with the amino acid sequence of SEQ ID NO:41, with a cysteine amino acid at position 48 of the GP5 protein in North American PRRSV strains, wherein the position number 48 is determined from sequence alignment with the amino acid sequence of SEQ ID NO:1, or at position 50 of European PRRSV strains, wherein the position number 50 is determined from sequence alignment with the amino acid sequence of SEQ ID NO:4, thereby vaccinating against PRRSV.