LACRIMAL ANTIBODY-RESPONSE OF SPECIFIC PATHOGEN-FREE CHICKENS AND CHICKENS WITH MATERNAL IMMUNITY AFTER INFECTIOUS-BRONCHITIS VIRUS VACCINATION

Lachrymal fluid specific IgG and IgA were detected by ELISA in chicken s with specific maternal antibodies and in chickens free of antibodies (SPF), after vaccination at 1 day of age with the H-120 vaccine strai n of infectious bronchitis virus. Samples were obtained at 3 day inter vals and until Day 37 of age. Optical densities obtained were in all i nstances low but significant differences could be detected within and between the experimental groups. Both class-specific immunoglobulins s howed a similar kinetic pattern. Nevertheless, the SPF group increased its IgA level on Day 13 while chickens with maternal immunity increas ed their level on Day 16. The antibody levels of both IgG and IgA were also different, being higher in the SPF group. In both chicken groups , higher levels of IgA than IgG were detected.