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.

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.

The present disclosure provides an N protein epitope mutation marker for preparing an epitope deletion-marked vaccine strain of type II porcine reproductive and respiratory syndrome virus (PRRSV) and use thereof, belonging to the technical field of biological products. In the mutation marker, one or more amino acids are mutated based on an epitope sequence at positions 92 to 103 of a C-terminal of an N protein of the type II PRRSV; and the epitope mutation marker has an amino acid sequence shown in SEQ ID NO: 1, where X.sub.1 is selected from the group consisting of T, P, and A; and X.sub.2 is selected from the group consisting of V and A.

The present invention relates to a method for preparing cDNA infectious clones based on the genome of an attenuated Porcine Reproductive and Respiratory Syndrome virus (PRRSV) and uses thereof for preparing efficacious and safety-enhanced vaccines against PRRSV. The invention further comprises an infectious cDNA clone obtainable by such method. The invention further provides an attenuated modified PRRSV, and immunogenic compositions and vaccines comprising that attenuated PRRSV. The present invention further provides the attenuated PRRSV for use in the prophylaxis and/or the treatment of PRRSV infections, and the attenuated PRRSV for use as vaccine or medicament in the prophylaxis and/or the treatment of PRRSV infections.

The present disclosure relates to an immune-enhanced virus vaccine based on virus surface engineering. A linker peptide according to one aspect has the property of being attachable to a virus, and may be used as a linker that may effectively bind an immune-enhancing substance, which activates the immune system, to the surface of the virus, and thus may improve the immunogenicity of the vaccine. By incorporating the linker peptide into virus surface engineering technology, an immune-enhancing substance may be attached to the surface of the virus, which may be useful in an immune-enhanced vaccine platform.

The present invention relates to modified, live Porcine Reproductive and Respiratory Syndrome viruses. Viruses were genetically analyzed and selected based on phylogenetic grouping for modification by repeated passage in tissue culture. The modified, live viruses were assessed for the ability to provide protective immunity to heterologous viruses. The modified, live viruses are useful in vaccines, particularly in vaccines which can treat infection of swine by multiple heterologous viruses.

The present invention belongs to the field of animal health and provides means to study Porcine Reproductive and Respiratory Syndrome (PRRS), a viral disease affecting swine, and for the development of vaccines, therapeutics and diagnostics for the prophylaxis, treatment and diagnosis of PRRS. In a first consideration, the invention relates to a new PRRS virus variant. and, in a second consideration, to a nucleic acid sequence which comprises the genome of an infectious genotype I (EU) PRRS virus clone. Based on this, new PRRS vaccine candidates with improved properties are provided.

This invention provides a protein-A or protein-G treated Mycoplasma hyopneumoniae (M.hyo) antigen that is compatible with antigens from other swine pathogens, wherein the M.hyo antigen is an M.hyo culture supernatant.

The present invention is related to improved modified live PRRS vaccines containing new PRRSV European strains of PRRSV and methods of use and manufacture of such vaccines.

Disclosed herein are methods and compositions for treating or preventing Porcine reproductive and respiratory syndrome (PRRS) infection in a subject.