Monitoring Of Infectious Bursal Disease (IBD) Vaccination With VAXXITEK® HVT+IBD And Live Modified IBD Vaccine In Two Genetic Lines Of Layer Pullets Reared In Field Conditions

Delvecchio A., Gauthier J.C., Lemiere S. & Prandini F. 


Despite a noticeable spread of the live modified IBD vaccine to all the groups during the study, a benefit in terms of increase of day 35 post-vaccination Newcastle disease vaccination sero-conversion was evidenced, as it can be expected in field conditions, with 1-2 log2 higher titres on average. A transient perturbation of growth was evidenced in more susceptible to IBD white layer pullets right after the live modified IBD vaccine application, that was not observed in the brown layer pullets, neither in the white layer genetics unvaccinated controls, nor in the HVT-IBD vector vaccine vaccinates. These ‘tiny’ differences observed are typical of clinical studies in field conditions, in which many factors interact with vaccine take.