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Efficacy of Phase I and Phase II Coxiella burnetii Bacterin Vaccines in a Pregnant Ewe Challenge Model

Authors :
Sarah E. Williams-Macdonald
Mairi Mitchell
David Frew
Javier Palarea-Albaladejo
David Ewing
William T. Golde
David Longbottom
Alasdair J. Nisbet
Morag Livingstone
Clare M. Hamilton
Stephen F. Fitzgerald
Søren Buus
Emil Bach
Annemieke Dinkla
Hendrik-Jan Roest
Ad P. Koets
Tom N. McNeilly
Source :
Vaccines, Vol 11, Iss 3, p 511 (2023)
Publication Year :
2023
Publisher :
MDPI AG, 2023.

Abstract

The bacterium Coxiella burnetii can cause the disease Q-fever in a wide range of animal hosts. Ruminants, including sheep, are thought to play a pivotal role in the transmission of C. burnetii to humans; however, the only existing livestock vaccine, namely, Coxevac® (Ceva Animal Health Ltd., Libourne, France), a killed bacterin vaccine based on phase I C. burnetii strain Nine-Mile, is only approved for use in goats and cattle. In this study, a pregnant ewe challenge model was used to determine the protective effects of Coxevac® and an experimental bacterin vaccine based on phase II C. burnetii against C. burnetii challenge. Prior to mating, ewes (n = 20 per group) were vaccinated subcutaneously with either Coxevac®, the phase II vaccine, or were unvaccinated. A subset of pregnant ewes (n = 6) from each group was then challenged 151 days later (~100 days of gestation) with 106 infectious mouse doses of C. burnetii, Nine-Mile strain RSA493. Both vaccines provided protection against C. burnetii challenge as measured by reductions in bacterial shedding in faeces, milk and vaginal mucus, and reduced abnormal pregnancies, compared to unvaccinated controls. This work highlights that the phase I vaccine Coxevac® can protect ewes against C. burnetii infection. Furthermore, the phase II vaccine provided comparable levels of protection and may offer a safer and cost-effective alternative to the currently licensed vaccine.

Details

Language :
English
ISSN :
2076393X
Volume :
11
Issue :
3
Database :
Directory of Open Access Journals
Journal :
Vaccines
Publication Type :
Academic Journal
Accession number :
edsdoj.3c2c8447b9405e9658bda2802a97a5
Document Type :
article
Full Text :
https://doi.org/10.3390/vaccines11030511