Efficacy of Single dose recombinant HVT-IBDV vaccination (Vaxxitek ®) against classical and variant IBDV strains

Francisco Perozo, Pedro Villegas, Linda Purvis, Rafael Fernandez & Julio Cruz


To assess the protection conferred by day-one vaccination using VAXXITEK®, (a recombinant HVT expressing the VP2 from a classical IBDV), one-day old SPF and/or commercial broilers were vaccinated and then challenged with classical or variant E IBDV strains at 18 or 28 days. Clinical signs, bursa/bodyweight ratio and bursal histopathology were evaluated. No clinical signs or IBDV challenge related lesions were observed in the VAXXITEK® vaccinated birds at both early and late challenge. Unvaccinated challenged birds showed significantly lower bursal indexes. Crossprotection was demonstrated for the variant E challenge. Results indicate that single dose recombinant HVT-IBDV vaccination protects against classical and variant IBDV strains.