Influence of Age and Congenital Immunity Upon Immunization with an Avian Infectious Bronchitis Vaccine

Abstract

A study of the serological and immune responses of birds of two different ages with or without a high level of congenital antibodies to infectious bronchitis virus (IBV) indicated that both young age and congenital immunity were important factors in preventing a satisfactory response to this vaccinal strain of IBV.Discrepancies between the serological and the response to challenge were noted in the younger groups of birds.