Effective vaccination against porcine reproductive and respiratory syndrome (PRRS) virus prior to weaning
AssigneeZoetis Services LLC
InventorsJay Gregory Calvert, Robert G. Ankenbauer, Jacqueline Gayle Marx, Douglas S. Pearce, Marcia L. Keith
Life of this patent
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Abstract
The invention provides isolated polynucleotide molecules that comprise a DNA sequence encoding an infectious RNA sequence encoding a genetically-modified North American PRRS virus, methods to make it and related polypeptides, polynucleotides, and various components. Vaccines comprising the genetically modified virus and polynucleotides and a diagnostic kit to distinguish between naturally infected and vaccinated animals are also provided.
Claims12
A method for inducing a protective immune response in a porcine animal against infection by a Porcine Reproductive and Respiratory Syndrome (PRRS) virus, the method comprising administering to said animal a vaccine comprising a modified live PRRS virus, and a carrier suitable for veterinary use, wherein said vaccine is administered to said animal prior to weaning;
- wherein said vaccine is safe and immunoprotective even if administered when said animal is no more than two weeks of age;
- wherein said modified live PRRS virus is prepared by attenuating a virulent PRRS virus in a permissive mammalian cell line that exogenously expresses porcine CD163 receptor protein, and recovering virus from the culture;
- and wherein said protective immune response provides a reduction in mortality in comparison to an unvaccinated animal infected with PRRS.
A method for inducing a protective immune response in a porcine animal against infection by a Porcine Reproductive and Respiratory Syndrome (PRRS) virus, the method comprising administering to said animal, prior to weaning, a vaccine comprising:
- (a) a modified live PRRS virus, (b) an infectious RNA molecule encoding said modified PRRS virus, (c) an isolated polynucleotide molecule comprising a DNA sequence encoding said infectious RNA molecule, (d) a viral vector comprising said infectious RNA molecule, or (e) a viral vector comprising said isolated polynucleotide molecule;
- and a carrier suitable for veterinary use;
- wherein said vaccine is administered to said animal prior to weaning;
- wherein said modified PRRS virus is prepared by attenuating a virulent PRRS virus on permissive mammalian cells exogenously expressing porcine CD163 receptor, wherein said modified PRRS virus exhibits reduced virulence in said animal in comparison to a wild-type or unmodified PRRS virus from which the modified virus was derived;
- and wherein said administration induces a protective immune response in a porcine animal against infection by a wild-type PRRS virus, wherein said protective immune response provides a reduction in mortality in comparison to an unvaccinated animal infected with PRRS.
Dependencies are inferred from the claim text.