Development of a heteroduplex mobility assay to identify field isolates of porcine reproductive and respiratory syndrome virus with nucleotide sequences closely related to those of modified live-attenuated vaccines.

Live-Attenuated Vaccines Related to Those of Modified Virus with Nucleotide Sequences Closely Reproductive and Respiratory Syndrome Assay To Identify Field Isolates of Porcine Development of a Heteroduplex Mobility

Genomic homology of ORF 5 gene sequence between modified live vaccine virus and porcine reproductive and respiratory syndrome virus challenge isolates is not predictive of vaccine efficacy

Objective: To test the efficacy of Ingelvac PRRS ATP (Boehringer Ingelheim Vetmedica Inc, St Joseph, Missouri), a modified live virus (MLV) vaccine, to protect against respiratory disease and lesions induced by challenge of growing pigs with one of three porcine reproductive and respiratory syndrome virus (PRRSV) field isolates (SDSU73, VR2385, and Mn-01-A1). On the basis of genome sequencing o...

Reversion of a live porcine reproductive and respiratory syndrome virus vaccine investigated by parallel mutations.

A live attenuated porcine reproductive and respiratory syndrome (PRRS) vaccine virus has been shown to revert to virulence under field conditions. In order to identify genetic virulence determinants, ORF1 from the attenuated vaccine virus and three Danish vaccine-derived field isolates was sequenced and compared with the parental strain of the vaccine virus (VR2332). This revealed five mutation...

Characterization of a serologic marker candidate for development of a live-attenuated DIVA vaccine against porcine reproductive and respiratory syndrome virus.

DIVA (differentiating infected from vaccinated animals) vaccines have proven extremely useful for control and eradication of infectious diseases in livestock. We describe here the characterization of a serologic marker epitope, so-called epitope-M201, which can be a potential target for development of a live-attenuated DIVA vaccine against porcine reproductive and respiratory syndrome virus (PR...

Different biological characteristics of wild-type porcine reproductive and respiratory syndrome viruses and vaccine viruses and identification of the corresponding genetic determinants.

Two attenuated vaccines, Ingelvac PRRS MLV and Ingelvac PRRS ATP, derived from VR2332 and JA142, respectively, have been used to control porcine reproductive and respiratory syndrome (PRRS) virus. However, there have been several field reports concerning the reversion of the vaccine virus to virulence. Furthermore, viruses genetically indistinguishable from the vaccines and wild-type parental v...