Immune response in chickens to infectious bronchitis virus, strain 33. III. Beta-propiolactone-inactivated and live-virus vaccines compared by statistical methods

SUMMARY The immunogenicity of 2 vaccines made of beta-propiolactoneinactivated or chicken-embryo-kidney-propagated avian infectious bronchitis virus, strain 33, were compared by statistical methods. Factors used for comparison were virus-neutralizing antibody and titers of virus isolated from trachea, lungs, and kidneys of contactchallenge-exposed birds. It was concluded there were no significant differences in the immunizing properties of the 2 vaccines.