Anti-SU antibody responses in client-owned cats following vaccination against feline leukaemia virus with two inactivated whole-virus vaccines (Fel-O-Vax® Lv-K and Fel-O-Vax® 5)

Westman, M., Norris, J., Malik, R., Hofmann-Lehmann, R., Parr, Y. A., Armstrong, E., McDonald, M. , Hall, E., Sheehy, P. and Hosie, M. J. (2021) Anti-SU antibody responses in client-owned cats following vaccination against feline leukaemia virus with two inactivated whole-virus vaccines (Fel-O-Vax® Lv-K and Fel-O-Vax® 5). Viruses, 13(2), 240. (doi: 10.3390/v13020240) (PMID:33546485) (PMCID:PMC7913631)

Abstract

A field study undertaken in Australia compared the antibody responses induced in client-owned cats that had been vaccinated using two inactivated whole feline leukaemia virus (FeLV) vaccines, the monovalent vaccine Fel-O-Vax® Lv-K and the polyvalent vaccine Fel-O-Vax® 5. Serum samples from 428 FeLV-uninfected cats (118 FeLV-vaccinated and 310 FeLV-unvaccinated) were tested for anti-FeLV neutralising antibodies (NAb) using a live virus neutralisation assay to identify 378 FeLV-unexposed (NAb-negative) and 50 FeLV-exposed (NAb-positive; abortive infections) cats, following by anti-surface unit (SU) FeLV-A and FeLV-B antibody ELISA testing. An additional 42 FeLV-infected cats (28 presumptively regressively infected, 14 presumptively progressively infected) were also tested for anti-SU antibodies. NAb-positive cats displayed significantly higher anti-SU antibody ELISA responses compared to NAb-negative cats (p < 0.001). FeLV-unexposed cats (NAb-negative) that had been vaccinated less than 18 months after a previous FeLV vaccination using the monovalent vaccine (Fel-O-Vax® Lv-K) displayed higher anti-SU antibody ELISA responses than a comparable group vaccinated with the polyvalent vaccine (Fel-O-Vax® 5) (p < 0.001 for both anti-FeLV-A and FeLV-B SU antibody responses). This difference in anti-SU antibody responses between cats vaccinated with the monovalent or polyvalent vaccine, however, was not observed in cats that had been naturally exposed to FeLV (NAb-positive) (p = 0.33). It was postulated that vaccination with Fel-O-Vax® 5 primed the humoral response prior to FeLV exposure, such that antibody production increased when the animal was challenged, while vaccination with Fel-O-Vax® Lv-K induced an immediate preparatory antibody response that did not quantitatively increase after FeLV exposure. These results raise questions about the comparable vaccine efficacy of the different FeLV vaccine formulations and correlates of protection

• Item Type: Articles
• Additional Information: This research was supported financially by the Australian Companion Animal Health Foundation (grant numbers 006/2013 and 004/2015). Mark Westman was supported by an Australian Postgraduate Award (APA), the Neil and Allie Lesue Scholarship, the Herbert Johnson Travel Grant Scholarship and an Endeavour Research Fellowship. Richard Malik was supported by the Valentine Charlton Bequest. Yasmin A. Parr was supported by a University of Glasgow Industrial Partnership PhD studentship with IDEXX Corporation held by Margaret J. Hosie.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hosie, Professor Margaret and McDonald, Mr Mike and Parr, Dr Yasmin and Westman, Dr Mark

Creator Roles

Westman, M.: Conceptualization, Visualization, Methodology, Formal analysis, Investigation, Data curation, Writing – original draft, Project administration, Funding acquisition
Parr, Y. A.: Investigation, Data curation, Writing – review and editing
McDonald, M.: Data curation, Writing – review and editing
Hosie, M. J.: Conceptualization, Visualization, Methodology, Writing – review and editing, Supervision, Project administration, Funding acquisition

• Authors: Westman, M., Norris, J., Malik, R., Hofmann-Lehmann, R., Parr, Y. A., Armstrong, E., McDonald, M., Hall, E., Sheehy, P., and Hosie, M. J.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity; College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine; College of Medical Veterinary and Life Sciences > School of Infection & Immunity > Centre for Virus Research
• Journal Name: Viruses
• Publisher: MDPI
• ISSN: 1999-4915
• ISSN (Online): 1999-4915
• Published Online: 03 February 2021
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Viruses 13(2): 240
• Publisher Policy: Reproduced under a Creative Commons License