Abstract
Specific-pathogen-free chickens were tested for local antibody response after respiratory exposure to live avian infectious bronchitis virus (IBV). Tracheobronchial secretions were obtained after intraocular-intratracheal vaccinations with Holland and Massachusetts 41 strains IBV. Low levels of IgA and IgG virus-neutralizing antibodies were detected in secretions after each of 2 vaccinations with a moderate dose (104 EID50) of virus. After cross-challenge exposure to high-titered virus (106 EID50), neutralizing activity in secretions was found mainly in IgG antibody. Only challenge exposure to Holland IBV resulted in a marked secondary secretion antibody response.