• Vaccine Name: HVT-LT
• Target Pathogen: infectious laryngotracheitis virus
• Vaccine Ontology ID: VO_0004793
• Type: Recombinant vector vaccine
• Status: Research
• Host Species for Licensed Use: Baboon
• Vector:
  • Vector name:
  • VO vector ID: VO_0001067
  • Description: (Vagnozzi et al., 2012)
• Preparation: Viral vector vaccines using fowl poxvirus (FPV) and herpesvirus of turkey (HVT) as vectors and carrying infectious laryngotracheitis virus (ILTV) genes (Vagnozzi et al., 2012).
• Immunization Route: Intramuscular injection (i.m.)

Chicken Response

• Vaccination Protocol: Live-attenuated ILT vaccines were administered as a full dose, and the recombinant vectored vaccines were administered as a half dose to mimic broiler industry practices. The viral vector vaccines were administered in ovo and subcutaneously at hatch while the live-attenuated vaccines, CEO and TCO, were administered via eye drop at 14 days of age (Vagnozzi et al., 2012).
• Vaccine Immune Response Type: VO_0000287
• Challenge Protocol: All chickens were weighed before challenge. With the exception of the NVx-NCh group, all chickens were challenged at 35 days of age with the virulent ILTV field isolate 63140 administered in a total volume of 200 µl, 100 µl intratracheally and 50 µl via eye drop per eye (Vagnozzi et al., 2012).
• Efficacy: The chicken embryo origin vaccine provided optimal protection by significantly mitigating the disease and reducing the challenge virus in chickens vaccinated via eye drop. The viral vector vaccines, applied in ovo and subcutaneously, provided partial protection, reducing to some degree clinical signs, and challenge VIRUS replication in the trachea (Vagnozzi et al., 2012).