Paratuberculosis vaccination specific and non-specific effects on cattle lifespan

Area of Science:

• Veterinary immunology
• Infectious disease epidemiology
• Animal health economics

Background:

• Paratuberculosis (PTB) is a significant disease in cattle, causing economic losses.
• Non-specific effects (NSE) of vaccines on overall mortality have been observed in humans but not extensively studied in animals.
• The concept of trained immunity suggests vaccines can induce broader immune system memory beyond specific pathogen response.

Purpose of the Study:

• To investigate if cattle vaccination against PTB induces non-specific effects (NSE) on overall mortality.
• To assess the persistence and magnitude of PTB-specific and NSE from vaccination.
• To evaluate the potential economic and systemic benefits of PTB vaccination in cattle.

Main Methods:

• Survival analysis of vaccinated and control cattle (n=4769) across 30 farms in the Basque Country, Spain, over 1-13 years.
• Utilized slaughterhouse data for PTB prevalence to estimate age-specific incidence.
• Calculated PTB-specific and NSE by subtracting PTB incidence from mortality differences between vaccinated and control groups.

Main Results:

• Calf vaccination (<3 months) showed a maximum 33.9% mortality reduction at 2-3 years, with a 24.5% NSE.
• Overall, calf vaccination provided 26.5% yearly mortality protection (11.1% PTB-specific, 15.4% NSE), persisting up to 6-7 years.
• No adverse effects were observed in female cattle vaccinated with killed vaccines.

Conclusions:

• Cattle PTB vaccination demonstrates significant NSE on total mortality, supporting the trained immunity theory in an animal field study.
• Mortality reduction through vaccination offers potential economic benefits, improving livestock system efficiency and possibly reducing antibiotic use.
• Findings challenge previous literature regarding killed vaccines and suggest a broader protective role for PTB vaccination in cattle health.