title: Report on the international workshop on alternative methods for Leptospira vaccine potency testing: state of the science and the way forward.
abstract: Routine potency testing of Leptospira vaccines is mostly conducted using a vaccination-challenge test that involves large numbers of hamsters and unrelieved pain and distress. NICEATM, ICCVAM, and their international partners organized a workshop to review the state of the science of alternative methods that might replace, reduce, and refine the use of animals for veterinary Leptospira vaccine potency testing and to identify ways to advance improved alternative methods. Vaccine manufacturers were encouraged to initiate or continue product-specific validation using in vitro enzyme-linked immunosorbent assays as replacements for potency testing of four common Leptospira serogroups. Participants discussed the potential for eliminating the back-titration procedure in the hamster challenge assay, which could reduce animal use by 50% for each individual potency test. Further animal reduction may also be possible by using cryopreserved Leptospira stock to replace continual passaging through hamsters. Serology assays were identified as a way to further reduce and refine animal use but should be considered only after attempting in vitro assays. Workshop participants encouraged consideration of analgesics and use of earlier humane endpoints when the hamster vaccination-challenge potency assay is used. International harmonization of alternative potency methods was recommended to avoid duplicative potency testing to meet regionally different requirements.
authors.affiliation: National Toxicology Program Interagency Center for The Evaluation of Alternative Toxicological Methods (NICEATM), Division of The National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, P.O. Box 12233, MD:K2-16, Research Triangle Park, NC 27709, USA.
authors.forename: William
authors.initials: W
authors.lastname: Stokes
authors.forename: Geetha
authors.initials: G
authors.lastname: Srinivas
authors.forename: Richard
authors.initials: R
authors.lastname: McFarland
authors.forename: Jodie
authors.initials: J
authors.lastname: Kulpa-Eddy
authors.forename: Warren
authors.initials: W
authors.lastname: Casey
authors.forename: Angela
authors.initials: A
authors.lastname: Walker
authors.forename: Hans
authors.initials: H
authors.lastname: Draayer
authors.forename: Randy
authors.initials: R
authors.lastname: Sebring
authors.forename: Karen
authors.initials: K
authors.lastname: Brown
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Balks
authors.forename: Catrina
authors.initials: C
authors.lastname: Stirling
authors.forename: Eric
authors.initials: E
authors.lastname: Klaasen
authors.forename: Richard
authors.initials: R
authors.lastname: Hill
authors.forename: Byron
authors.initials: B
authors.lastname: Rippke
authors.forename: Kevin
authors.initials: K
authors.lastname: Ruby
authors.forename: David
authors.initials: D
authors.lastname: Alt
authors.forename: Suman
authors.initials: S
authors.lastname: Mukhopadhyay
authors.forename: Hajime
authors.initials: H
authors.lastname: Kojima
authors.forename: Nelson
authors.initials: N
authors.lastname: Johnson
authors.forename: Lori
authors.initials: L
authors.lastname: Rinckel
authors.forename: Vivian
authors.initials: V
authors.lastname: Doelling
authors.forename: Brett
authors.initials: B
authors.lastname: Jones
mesh_terms: D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology / Q000494:pharmacology; D006224:Cricetinae; D004493:Education; D006801:Humans; D007919:Leptospira / Q000276:immunology*; D007922:Leptospirosis / Q000097:blood / Q000276:immunology / Q000517:prevention & control; D064166:Vaccine Potency
chemical_list: D001428:Bacterial Vaccines
keywords: Alternative methods; Leptospira vaccines; Potency; Reduction; Refinement; Replacement