How to translate text using browser tools
1 December 2010 Protection Against Infectious Laryngotracheitis by In Ovo Vaccination with Commercially Available Viral Vector Recombinant Vaccines
Deirdre I. Johnson, Ariel Vagnozzi, Fernanda Dorea, Sylva M. Riblet, Alice Mundt, Guillermo Zavala, Maricarmen García
Author Affiliations +
Abstract

Infectious laryngotracheitis (ILT) is a highly contagious respiratory disease of chickens caused by infectious laryngotracheitis virus (ILTV). The disease is mainly controlled through biosecurity and by vaccination with live-attenuated vaccines. The chicken embryo origin (CEO) vaccines, although proven to be effective in experimental settings, have limited efficacy in controlling the disease in dense broiler production sites due to unrestricted use and poor mass vaccination coverage. These factors allowed CEO vaccines to regain virulence, causing long lasting and, consequently, severe outbreaks of the disease. A new generation of viral vector fowl poxvirus (FPV) and herpesvirus of turkey (HVT) vaccines carrying ILTV genes has been developed and such vaccines are commercially available. These vaccines are characterized by their lack of transmission, lack of ILTV-associated latent infections, and no reversion to virulence. HVT-vectored ILTV recombinant vaccines were originally approved for subcutaneous HVT or transcutaneous (pox) delivery. The increased incidence of ILTV outbreaks in broiler production sites encouraged the broiler industry to deliver the FPV-LT and HVT-LT recombinant vaccines in ovo. The objective of this study was to evaluate the protection induced by ILTV viral vector recombinant vaccines after in ovo application in 18-day-old commercial broiler embryos. The protection induced by recombinant ILTV vaccines was assessed by their ability to prevent clinical signs and mortality; to reduce challenge virus replication in the trachea; to prevent an increase in body temperature; and to prevent a decrease in body weight gain after challenge. In this study, both recombinant-vectored ILTV vaccines provided partial protection, thereby mitigating the disease, but did not reduce challenge virus loads in the trachea.

Deirdre I. Johnson, Ariel Vagnozzi, Fernanda Dorea, Sylva M. Riblet, Alice Mundt, Guillermo Zavala, and Maricarmen García "Protection Against Infectious Laryngotracheitis by In Ovo Vaccination with Commercially Available Viral Vector Recombinant Vaccines," Avian Diseases 54(4), 1251-1259, (1 December 2010). https://doi.org/10.1637/9401-052310-Reg.1
Received: 23 May 2010; Accepted: 1 September 2010; Published: 1 December 2010
KEYWORDS
fowl poxvirus
herpes virus of turkeys
In ovo
infectious laryngotracheitis virus
protection
recombinant viral vectored vaccines
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top