The potential of a microparticulate vaccine delivery system ineliciting a specific humoral response in the upper respiratory tract ofcalves was evaluated. Microparticles composed of poly(lactideco-glycolide) containing ovalbumin, a model immunogen, wereprepared by a solvent evaporation technique. The microparticleswere under 10μm in diameter as determined by fluorescenceactivated cell sorter (FACS) analysis.Following immunisation, the microparticles induced production ofspecific secretory IgA (sIgA) in nasal samples.The sIgA was detectedafter only one week and persisted throughout the length of the study.Additionally, the effects of microencapsulated synthetic peptides(F peptide (0.5mg) and G peptide (0.5mg), representing knownprotective epitopes against bovine respiratory syncytial virus (BRSV),on the cellular and humoral immune responses of calves wereinvestigated.∗ No significant change in the cellular immune response wasdetected.* The secretory IgA response was significantly more prolongedfollowing administration of the SF (F111-148) peptide whencompared with the SG (G174-187) peptide.* It is concluded that microparticles incorporating antigens showpotential in the quest for generating complete protection in theyoung bovine against respiratory tract pathogens.* Vaccination of calves with the SF (F111-148) and SG (G174-187)peptide resulted in a significant reduction in the requirement to treat withantibiotics for respiratory disease in the post-vaccination period.
AGRIP End of Project Reports
Teagasc End-of-Project Reports