Differential immunoassay for prrs vaccine antibody

Abstract

The present invention relates to immunoassays for serologically differentiating animals naturally infected with PRRS virus from animals vaccinated against PRRS. The immunoassays provide detection of at least a portion of the N terminal region of the 2b portion of PRRSV. The immunoassay is preferably an enzyme-linked immunosorbent assay (ELISA).

Description

BACKGROUND OF THE INVENTION[0001]Porcine reproductive and respiratory syndrome (PRRS), often characterized by late-term abortions and still births in sows and respiratory disease in nursery pigs, has resulted in extensive economic losses in the swine industry for over a decade. (16). First described in 1987 in the United States as “mystery swine disease”, it spread rapidly, being reported in Europe in 1990 and subsequently across the world.[0002]Porcine reproductive and respiratory syndrome virus (PRRSV), the causative agent of PRRS, is a small, enveloped, positive-stranded RNA virus consisting of eight overlapping open reading frames (ORFs). (19, 21). The virus is genetically, antigenically, and pathogenically heterogenic. (16). Substantial sequence divergence exists between the European and North American genotypes of the virus. (1, 9, 11-16, 20-21). Within each genotype, the PRRSV genomic sequences also vary significantly. (8, 13, 14, 20).[0003]Modified live-attenuated vaccines (...

AI Technical Summary

Problems solved by technology

Porcine reproductive and respiratory syndrome (PRRS), often characterized by late-term abortions and still births in sows and respiratory disease in nursery pigs, has resulted in extensive economic losses in the swine industry for over a decade.

Many of these acute outbreaks occurred in PRRSV MLV-vaccinated herds, suggesting that the commonly used modified live-attenuated vaccines are not fully effective.

Because these assays are costly and time-consuming, they are not very well suited for routine large-scale screening of viruses.

The mismatches cause structural distortions in the newly formed DNA molecule, resulting in heteroduplexes with reduced mobility on a polyacrylamide gel.

The HMA, however, suffers from some of the disadvantages inherent in all screening techniques.

Thus, these methods typically underestimate the true diversity of a sequence mixture.

Currently, no such strategies exist in the industry for PRRS that are effective.

While there is a commercial ELISA available for detecting antibody against PRRS virus, this commercial ELISA cannot differentiate vaccine-induced antibody from natural infection.

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