title: Confidence in indirect assessment of foot-and-mouth disease vaccine potency and vaccine matching carried out by liquid phase ELISA and virus neutralization tests.
abstract: The necessity of avoiding the use of animals in vaccine potency testing has been widely recognized. The repeatability and reproducibility of the Expected Percentage of Protection (EPP) as a serological potency surrogate for A24 Cruzeiro foot-and-mouth disease virus (FMDV) strain was assessed, and compared with the results obtained with challenge in the Protection against Podal Generalization (PPG) test. To determine the EPPs, the serum titers obtained by liquid phase blocking competitive ELISA (lpELISA) and virus neutralization (VNT) in 10 potency trials using the same A24 Cruzeiro vaccine, were interpolated into previously validated logit transformation curves that correlate PPG with serology. Indirect serological assessment of vaccine matching between the serotype A FMDV strains A24 Cruzeiro and A/Argentina/01 was also carried out by lpELISA and VNT. The results obtained in this study strongly support the replacement of challenge tests for vaccine potency by indirect serological assays, at least for A24 Cruzeiro FMDV strain. While determination of EPPs by lpELISA titers showed an excellent repeatability, reproducibility and concordance with PPG for vaccine potency, assessments of cross-protection by VNT titers were more consistent with the PPG outcome.
authors.affiliation: Centro de Virología Animal, Instituto de Ciencia y Tecnología Dr. César Milstein, CONICET, Saladillo 2468, (1440) Buenos Aires, Argentina.
authors.forename: Blanca
authors.initials: B
authors.lastname: Robiolo
authors.forename: José
authors.initials: J
authors.lastname: La Torre
authors.forename: Eduardo
authors.initials: E
authors.lastname: Maradei
authors.forename: Claudia Perez
authors.initials: CP
authors.lastname: Beascoechea
authors.forename: Alejandro
authors.initials: A
authors.lastname: Perez
authors.forename: Cristina
authors.initials: C
authors.lastname: Seki
authors.forename: Eliana
authors.initials: E
authors.lastname: Smitsaart
authors.forename: Norberto
authors.initials: N
authors.lastname: Fondevila
authors.forename: Eduardo
authors.initials: E
authors.lastname: Palma
authors.forename: Nesya
authors.initials: N
authors.lastname: Goris
authors.forename: Kris
authors.initials: K
authors.lastname: De Clercq
authors.forename: Nora
authors.initials: N
authors.lastname: Mattion
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control; D002460:Cell Line; D006224:Cricetinae; D056738:Cross Protection; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005536:Foot-and-Mouth Disease / Q000517:prevention & control*; D009500:Neutralization Tests / Q000379:methods*; D015203:Reproducibility of Results; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D014765:Viral Vaccines