A Study of Infectious Laryngotracheitis Virus. I. Comparison of Serologic and Immunogenic Properties

Publisher Website
Google Scholar
Abstract
The serologic and immunogenic properties of 9 isolates of infectious LT were compared. Groups of 30 birds were immunized with each of the 9 isolates and then divided into groups of 3 birds for sinus challenge with each of the 8 heterologous and the homologous isolates. Immune serum for virus neutralization tests was prepared for each of the isolates in similar but different groups of chickens by repeated inoculations. Cross virus-neutralization tests in the CAS of embryonating eggs revealed little neutralizing capacity with serum prepared against isolate 9, a strain obtained from one commercial vaccine; and low neutralizing capacity of isolate 8, a strain of known low virulence. The other sera, with a few exceptions, had as good or better neutralizing capacities for the heterologous than for the homologous isolate. Cross-challenge results revealed that only 2 immunized groups were immune to all 8 heterologous isolates. In all other immunized groups some of the birds in each group developed symptoms or histologic lesions following challenge. There was no real correlation between serum virus-neutralizing indices and resistance to challenge.

This publication has 1 reference indexed in Scilit: