Comparison of infectious bursal disease live vaccines and a HVT-IBD vector vaccine and their effects on the immune system of commercial layer pullets.

Infectious bursal disease (IBD) is an economically important disease affecting poultry production worldwide. Previous experimental studies indicated that IBD live vaccination may induce transient immunosuppression, leading to suboptimal vaccine responses and therefore insufficient protection against other pathogens. Layer pullets are commonly not only vaccinated against IBD within their rearing period, but also against a variety of other pathogens.