A non-naturally occurring porcine reproductive and respiratory syndrome virus (PRRSV) is provided herein, and methods of making and using the non-naturally occurring PRRSV also are provided.

Provided herein are embodiments relating to porcine reproductive and respiratory syndrome (PRRS) virus, compositions comprising the virus, and methods of using the virus. The virus may be used to immunize a mammal, including swine. Methods for generating an immune response against PRRS virus in swine by administering a composition comprising the virus are provided.

This disclosure provides isolated infectious polynucleotides, such as infectious clones, having a nucleotide sequence with identity to PRRS viruses such as VR-2332, Lelystad, or others, and optionally further including a deletion in a region of ORF1 that encodes the nsp2 polypeptide.

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

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.

The present invention relates to Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) mutant strains having increased stability; compositions containing the strains or antigens derived therefrom; vaccines containing the strains, including killed, attenuated or subunit vaccines; nucleic acids encoding PRRSV polypeptides, polypeptides encoded by the nucleic acids, including antigenic fragments thereof; antibodies which specifically bind to said polypeptides, and methods making and using thereof.

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.

Methods are provided for eliciting heterologous immunogenicity against heterologous porcine reproductive and respiratory syndrome virus (PRRSV) strains to allow assessment of innate immunity and adaptive immunity. In other aspects are provided methods for determining the efficacy of a vaccine against PRRSV. In still other aspects are provided methods for predicting the efficacy of a vaccine against PRRSV in pigs suspected of having an infection with PRRSV.

The present disclosure generally relates to viral-based expression systems suitable for the production of molecule of interests in recombinant host cells. The disclosure particularly relates to nucleic acid constructs, such as expression vectors, containing a modified arterivirus genome or replicon RNA in which at least some of its original viral sequence has been deleted. Also included in the disclosure are viral-based expression vectors including one or more expression cassettes encoding heterologous polypeptides. In some embodiments, the expression cassettes are configured and positioned at defined locations on the viral genome so as to enable expression of the heterologous polypeptides in a tunable manner.

Disclosed are an rBJ-VVL plasmid, a mutant strain of NADC34-like PRRSV-2 and a preparation method therefor and application thereof. Further disclosed is an NADC34-like PRRSV-2-specific vaccine. In the present disclosure, a modified strain rBJ-VVL with tropism for Marc-145 cells is obtained by precisely mutating an amino acid at positions 91/97/98 of GP2a; the modified virus constructed in the present disclosure can be propagated in Marc-145 cells, cause cytopathic effects and form plaques when inoculated into Marc-145 cells for serial passage; the resulting Marc-145 cell-passaged viruses have an extremely viral load, and a large number of new progeny viruses can be obtained in a short time; and the Marc-145-adapative modified strain cultured in the present disclosure is used to create a first NADC34-like PRRSV-2-specific vaccine.