The antigenicity and protective effect of 3 strains of avian infectious bronchitis virus inactivated by beta-propiolactone were studied. Chickens administered 2 doses of the inactivated Connecticut strain (IBV-46) vaccine by aerosol at 3-week intervals had significant levels of virus-neutralizing antibodies and were resistant to infection by the Massachusetts strain (IBV-41) as determined by virus isolation attempts. Antibody levels in chickens given inactivated Iowa 33 and Iowa 609 were not significant and they were not resistant to infection by IBV-41.
Protective effect of an inactivated avian coronavirus vaccine administered by aerosol