Serological and shedding patterns after Coxiella burnetii vaccination in the third gestation trimester in dairy cows

Abstract

This study sought to assess the effects of an inactivated phase I vaccine against Coxiella burnetii at the start of the third trimester of gestation on serological profiles, bacterial shedding patterns and subsequent reproductive performance in dairy cows. Cows were randomly assigned to a control (n = 78) or a vaccinated (n = 78) group on days 171-177 of gestation. Samples of placenta and colostrums at parturition, vaginal fluid, faeces, milk (PCR identification) and blood (anti-C. burnetii antibody detection) were obtained on the day of treatment and on days 91-97 post partum, and also on parturition day and weekly on days 1-7, 8-14, 15-21, 22-28 and 29-35 post partum in a subset of 70 animals. By Kaplan-Meier survival analysis, no significant effect of vaccination was detected on any of the reproductive variables studied. According to the odds ratio, C. burnetii shedding on days 171-177 of gestation was highly correlated with seropositivity against C. burnetii (OR = 9.1), while vaccination was not linked to reduced shedding of the bacterium. In shedders compared to others, the likelihood of pregnancy to first AI decreased and increased by factors of 0.26 and 16.1 on days 1-35 and 91-97 post partum, respectively. In conclusion, when administered at the start of the third trimester of pregnancy, the inactivated C. burnetii phase I vaccine failed to reduce bacterial shedding.

Progression of Coxiella burnetii infection after implementing a two-year vaccination program in a naturally infected dairy cattle herd

“…In this sense, a recent study demonstrated that vaccination of already infected animals failed to reduce bacterial shedding [[30]]. The detection of positive environmental samples after almost two years of vaccination indicates that a long term vaccination and culling strategy is needed to reduce the potential for re-emergence of infection.…”

Coxiella burnetiitotal immunoglobulin G, phase I and phase II immunoglobulin G antibodies, and bacterial shedding in young dams in persistently infected dairy herds

“…Clinical examinations of the reproductive tract during the postpartum period were performed on a weekly basis with ultrasound. 50 Both herds had, in the past, returned positive real-time PCR (qPCR) results for C. burnetii in the bulk tank milk samples with excretion higher than 10 4 Coxiella/mL 10 and had seroprevalence levels of 46% and 53% for herds 1 and 2, respectively. 23 The characterization of the C. burnetii genotype in positive PCR placental tissues was performed through a multiplex IS1111-based endpoint PCR coupled with hybridization by reverse line blotting that classifies C. burnetii isolates into 8 genomic groups.…”

Does Coxiella burnetii Affect Reproduction in Cattle? A Clinical Update

“…Recently, two studies have examined the use of this vaccine during the dry period. Although it did not reduce shedding during post-partum period (Tutusaus et al 2014), the vaccine proved safe in that it did not increase the abortion rate and was able to improve the subsequent fertility of the herd, especially when applied to C. burnetii-seronegative animals . The question that arises is how vaccination against C. burnetii increases reproductive performance.…”

“…Although it did not reduce shedding during post‐partum period (Tutusaus et al. ), the vaccine proved safe in that it did not increase the abortion rate and was able to improve the subsequent fertility of the herd, especially when applied to C. burnetii‐seronegative animals (López‐Helguera et al. ).…”