The double-antigen ELISA concept for early detection of Erns-specific classical swine fever virus antibodies and application as an accompanying test for differentiation of infected from marker vaccinated animals
Journal
Transboundary and Emerging Diseases
Journal Volume
64
Journal Issue
6
Pages
2013-2022
Date Issued
2017
Author(s)
Meyer, Denise
Fritsche, S.
Luo, Yuzi
Engemann, Claudia
Blome, Sandra
Beyerbach, Martin
Qiu, Huaji
Becher, Paul
Postel, Alexander
Abstract
Emergency vaccination with live marker vaccines represents a promising control strategy for future classical swine fever (CSF) outbreaks, and the first live marker vaccine is available in Europe. Successful implementation is dependent on a reliable accompanying diagnostic assay that allows differentiation of infected from vaccinated animals (DIVA). As induction of a protective immune response relies on virus-neutralizing antibodies against E2 protein of CSF virus (CSFV), the most promising DIVA strategy is based on detection of Erns-specific antibodies in infected swine. The aim of this study was to develop and to evaluate a novel Erns-specific prototype ELISA (pigtype CSFV Erns Ab), which may be used for CSF diagnosis including application as an accompanying discriminatory test for CSFV marker vaccines. The concept of a double-antigen ELISA was shown to be a solid strategy to detect Erns-specific antibodies against CSFV isolates of different genotypes (sensitivity: 93.5%; specificity: 99.7%). Furthermore, detection of early seroconversion is advantageous compared with a frequently used CSFV E2 antibody ELISA. Clear differences in reactivity between sera taken from infected animals and animals vaccinated with various marker vaccines were observed. In combination with the marker vaccine CP7_E2alf, the novel ELISA represents a sensitivity of 90.2% and a specificity of 93.8%. However, cross-reactivity with antibodies against ruminant pestiviruses was observed. Interestingly, the majority of samples tested false-positive in other Erns-based antibody ELISAs were identified correctly by the novel prototype Erns ELISA and vice versa. In conclusion, the pigtype CSFV Erns Ab ELISA can contribute to an improvement in routine CSFV antibody screening, particularly for analysis of sera taken at an early time point after infection and is applicable as a DIVA assay. An additional Erns antibody assay is recommended for identification of false-positive results in a pig herd immunized with the licensed CP7_E2alf marker vaccine. © 2017 Blackwell Verlag GmbH
Subjects
classical swine fever virus; DIVA assay; DIVA vaccine; double-antigen ELISA; Erns-based antibody ELISA; serology
SDGs
Other Subjects
live vaccine; marker vaccine; virus antibody; virus antigen; virus vaccine; animal; blood; classical swine fever; Classical swine fever virus; cross reaction; enzyme linked immunosorbent assay; evaluation study; immunology; Pestivirus; pig; sensitivity and specificity; vaccination; veterinary; virology; Animals; Antibodies, Viral; Antigens, Viral; Classical Swine Fever; Classical swine fever virus; Cross Reactions; Enzyme-Linked Immunosorbent Assay; Pestivirus; Sensitivity and Specificity; Swine; Vaccination; Vaccines, Attenuated; Vaccines, Marker; Viral Vaccines
Type
journal article