VAXXITEK® HVT+IBD Field Trials In Commercial Layers

Rojas A. 


Commercial layer pullets were vaccinated with VAXXITEK HVT+IBD at hatch and tested over the course of 15 weeks for indications of infectious bursal disease (IBD). Bursal index, histologic scoring of the bursa and serology were used to measure efficacy of the product in these flocks. A very small percentage of birds had macroscopically atrophied bursas, as measured by bursal index. Histologic scores were on average very low. IBD ELISA titers were adequate to high. All these results indicated VAXXITEK HVT+IBD protected commercial layers against IBD. VAXXITEK HVT+IBD is a HVT vector vaccine expressing the IBD virus VP2 gene. Its efficacy has been demonstrated against different strains of IBD virus, including classical, very virulent and American variant IBD virus strains. The vaccine is also efficacious for Marek’s protection, making it two-fold protection. VAXXITEK HVT+IBD can be administered either in ovo (3 days before hatching) or by the subcutaneous route in 1-day old chicks, in the presence of high titers of maternal antibodies. The objectives of the study were to evaluate the field efficacy of the vaccine in commercial layers operations in Mexico.