TY - JOUR
T1 - Efficacy of Phase I and Phase II Coxiella burnetii Bacterin Vaccines in a Pregnant Ewe Challenge Model
AU - Williams-Macdonald, Sarah E.
AU - Mitchell, Mairi
AU - Frew, David
AU - Palarea-Albaladejo, Javier
AU - Ewing, David
AU - Golde, William T.
AU - Longbottom, David
AU - Nisbet, Alasdair J.
AU - Livingstone, Morag
AU - Hamilton, Clare M.
AU - Fitzgerald, Stephen F.
AU - Buus, Søren
AU - Bach, Emil
AU - Dinkla, Annemieke
AU - Roest, Hendrik Jan
AU - Koets, Ad P.
AU - McNeilly, Tom N.
PY - 2023/2/22
Y1 - 2023/2/22
N2 - 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.
AB - 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.
KW - Coxiella burnetii
KW - phase I
KW - phase II
KW - Q-fever
KW - sheep
KW - vaccine
U2 - 10.3390/vaccines11030511
DO - 10.3390/vaccines11030511
M3 - Article
AN - SCOPUS:85151565089
SN - 2076-393X
VL - 11
JO - Vaccines
JF - Vaccines
IS - 3
M1 - 511
ER -
