Control of Coxiella burnetii shedding in a dairy goat herd by annual offspring vaccination

• Published in: Vaccine Vol. 42; no. 25; p. 126125
• Main Authors: Bauer, Benjamin U., Herms, T. Louise, Jahnke, Rico, Ossowski, Nina, Walter, Mathias C., Frangoulidis, Dimitrios, Runge, Martin, Ganter, Martin, Knittler, Michael R.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 14-11-2024; Elsevier Limited
• Subjects: Abortion; Age; Age groups; Animals; Antibodies; Antibodies, Bacterial - blood; Antibodies, Bacterial - immunology; Antigens; Bacteria; Bacterial Shedding; Bacterial Vaccines - administration & dosage; Bacterial Vaccines - immunology; Blood; Chronology; Coxiella burnetii; Coxiella burnetii - immunology; Coxiellosis; Dairying; Epidemics; Female; Females; Fetuses; Genomic analysis; Germany; Goat Diseases - immunology; Goat Diseases - microbiology; Goat Diseases - prevention & control; Goats; Immunity (Disease); Immunization; Immunoglobulin G; Immunoglobulin G - blood; Infections; Livestock farming; Milk; Milk - immunology; Milk - microbiology; Neutralization; Neutralizing antibodies; Offspring; Pathogens; Phase-specific serology; Q Fever - immunology; Q Fever - prevention & control; Q Fever - veterinary; Sample size; Seasons; Shedding; Sheep; Small ruminants; Vaccination - methods; Vaccination - veterinary; Vaccines; Vagina; Zoonoses; Zoonosis; Germany; Immunization; Phase-specific serology; Zoonosis; Neutralizing antibodies; Small ruminants; Coxiellosis
• ISSN: 0264-410X; 1873-2518; 1873-2518
• DOI: 10.1016/j.vaccine.2024.07.026

•A Coxiella burnetii vaccination program targeting only doelings in a positive herd was monitored for five years.•A robust IgG Phase I response occurred after two vaccine doses in most age groups.•Neutralizing antibodies were present regardless of IgG levels.•Double vaccination induced a lasting humoral immune response in goats.•Double vaccination of doelings did not entirely prevent C. burnetii shedding short term.
A Coxiella burnetii vaccination program, targeting only doelings, was introduced on a German goat farm to curb bacterial shedding. In 2018, adults were vaccinated with a C. burnetii Phase I vaccine at three-weeks apart following pathogen diagnosis, with a booster administered six months later due to sustained high shedding. From 2018 to 2021, doelings received two vaccine doses without any further boosters.
To assess the program’s efficacy, vaginal swabs from up to 40 animals per age group were collected during kidding seasons from 2019 to 2022. Bulk tank milk (BTM) samples were gathered monthly from January 2018 to October 2022 to monitor herd-level shedding. Real-time PCR analysis determined genome equivalents in all three sample types. Serum samples were taken before the initial immunization and during the post-kidding season from up to 40 goats per age group annually from 2018 to 2022. Phase-specific ELISAs determined IgG Phase I and Phase II antibodies. Additionally, two serum samples per age group from 2022 were analyzed using a neutralization assay.
A few goats continued shedding small quantities during subsequent kidding seasons. Although positive BTM samples decreased, they displayed an undulating trend. Most age groups exhibited robust IgG Phase I responses and lower IgG Phase II levels post immunization. Mean IgG levels remained elevated until the study ended compared to pre-vaccination levels in most age groups. Additionally, neutralizing antibodies were present regardless of IgG response. Overall, double vaccination induced lasting antibody levels, but did not entirely prevent C. burnetii shedding. The resilience of the observed humoral immune activity requires further investigation.