Efficacy of Administration of Priming Vaccination Against IB Questioned


Dr. Maggie Thompson of the PDRC, University of Georgia recently presented data on evaluation of the efficacy of administration of live attenuated infectious bronchitis vaccines to prime immunity.  Advances in technology now allow rapid PCR-detection of the DNA of specific variants including Massachusetts, Arkansas, Connecticut, Delaware and Georgia strains.  Sampling choanal clefts after vaccination and correlation with ELISA serology showed that, vaccination “takes” were suboptimal in half the flocks evaluated, subsequently correlated with low and variable serum antibody response. 


Adequate levels of immunity were achieved in trials involving careful administration of live attenuated IBV and ND vaccines applied by coarse spray. This is consistent with the It is axiom that “many birds are vaccinated but not all of them are immunized” a frequently quoted reality coined by Dr. James Beard.


Flocks require effective administration of vaccines to achieve their genetic potential in the face of challenge with multiple strains of IBV. Available vaccines are effective but only if diligently administered.