Immunogenicity of Bacillus Calmette-Guérin in pigs: potential as a translational model of non-specific effects of BCG

Background Clinical and immunological studies in humans show that the live attenuated Bacillus Calmette-Guérin (BCG) vaccine has beneficial non-specific effects, increasing resistance against diseases other than tuberculosis. The underlying mechanisms are currently being explored. pig exhibits considerable physiological similarity to anatomy physiology, suggesting similar responses BCG could be expected. Studies of effects pigs scarce. We investigated feasibility using as a large animal model investigate BCG. Methods In series experiments, we randomized newborn or young piglets from conventional farms receiving placebo persistence bacteria various tissues, immunogenicity ex vivo blood vitro stimulation assays, acute phase protein clinical heterologous infectious challenge with influenza A virus Actinobacillus pleuropneumoniae . Results was generally well tolerated. contrast humans, no skin reaction form abscesses, ulcers, scars observed. Live recovered draining lymph nodes 2/13 animals 20 weeks after vaccination. Specific IFN-γ antigen-specific re-stimulation mycobacterial antigen were increased but not TNF-responses TLR2 TLR4 agonists. few genes differentially expressed vaccination, including antiviral RIG-I CSF1 , although effect disappeared correction for multiple testing. symptoms bacterial viral respiratory infections did differ, nor copies nasopharyngeal samples challenge. However, response significantly reduced BCG-vaccinated A. Discussion safe pigs, inducing specific responses, our corroborate innate responsiveness seen humans. dose challenges may have been sub-optimal. Even so, infection animals.