title: Avidity and subtyping of specific antibodies applied to the indirect assessment of heterologous protection against Foot-and-Mouth Disease Virus in cattle.
abstract: Serological assessment of the heterologous response among Foot-and-Mouth Disease Virus (FMDV) strains is mainly performed by virus neutralization test (VNT), liquid phase blocking ELISA and complement fixation assay. In this study two high-throughput ELISA techniques, avidity and IgG subtype ELISA, were developed and used to further characterize heterologous antibody responses in cattle during vaccination and challenge. Both assays were applied to a set of previously characterized sera from animals immunized with an inactivated A24 Cruzeiro/Brazil/55 (A24 Cruzeiro) strain monovalent FMDV vaccine and challenged with the heterologous A/Argentina/2001 (A/Arg/01) strain. Single dilution avidity ELISA assessment showed that animals that were protected against A/Arg/01 challenge had higher avidity antibodies to this heterologous strain than non-protected cattle. Animals with low or even undetectable anti-A/Arg/01 serum-neutralizing titers that passed the heterologous challenge presented higher IgG1/IgG2 ratio than non-protected animals. In this study, the three assessments (VNT and both ELISAs) discriminated between protected and not protected animals against a heterologous challenge. The combination of these techniques may be applied to complement current indirect serological vaccine-matching assessments. The measurement of these qualitative parameters may provide additional information to understand the mechanisms underlying FMD heterologous responses and the induction of cross-protection in cattle.
authors.affiliation: INTA, Instituto de Virología, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, Buenos Aires, Argentina.
authors.forename: María Ángeles
authors.initials: MÁ
authors.lastname: Lavoria
authors.forename: Sebastián
authors.initials: S
authors.lastname: Di-Giacomo
authors.forename: Danilo
authors.initials: D
authors.lastname: Bucafusco
authors.forename: Olga Lucía
authors.initials: OL
authors.lastname: Franco-Mahecha
authors.forename: Daniel Mariano
authors.initials: DM
authors.lastname: Pérez-Filgueira
authors.forename: Alejandra Victoria
authors.initials: AV
authors.lastname: Capozzo
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D000915:Antibody Affinity; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000517:prevention & control*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005536:Foot-and-Mouth Disease / Q000276:immunology / Q000517:prevention & control*; D029544:Foot-and-Mouth Disease Virus / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood*; D009500:Neutralization Tests; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D014765:Viral Vaccines