If the whole virus is used in the vaccine, our rVP3 test will not differentiate anti-VP3 antibodies resulting from vaccination or wild virus infection, but if it is used a recombinant vaccine based on the VP2 protein, such as Vaxxitek HVT + IBD [44] or fp-IBD1 [45], a suspicious infection in the flock could be detected using the rVP3 ELISA, since the vaccinated animals will present anti-VP2 but not anti-VP3 antibodies. The gene discussed is ACAD8; the disease is infection.