H. Toro et al., INFECTIOUS-BRONCHITIS - EFFECT OF VIRAL DOSES AND ROUTES ON SPECIFIC LACRIMAL AND SERUM ANTIBODY-RESPONSES IN CHICKENS, Avian diseases, 41(2), 1997, pp. 379-387
An enzyme-linked immunosorbent assay was used to measure the effect of
various infectious bronchitis virus (IBV) (strain H-120) vaccine dose
s and routes of immunization on specific lacrimal and serum antibody r
esponses. The results of the first trial showed that the maximum dose,
10(6) median embryo infective doses (EID(50)s), delivered by the ocul
ar route elicited both a systemic and a local antibody response in the
vaccinated chickens. Lower doses of vaccinal virus, 10(4) (median dos
e) and 10(2) (minimum dose) EID50 delivered by the same route did not
induce a detectable systemic antibody response. A significant increase
of IBV-specific lacrimal IgA was elicited by both the maximum and the
median vaccine doses. The low vaccine dose (10(2) EID50) did not indu
ce a detectable increase of lacrimal IgA. In a second trial approximat
ely the same vaccine dose was administered to different chicken groups
by ocular instillation, drinking water, spray, and cloaca. The result
s showed that all routes of vaccination tested, including the cloacal
route, resulted in an increase of specific serum antibodies. Higher Ig
G levels were detected throughout the experimental period after vaccin
ation by the ocular route as compared with vaccination via the drinkin
g water. All routes of vaccination tested resulted in an increase of s
pecific IgA. in lacrimal fluid. The vaccine application methods spray,
ocular instillation, and drinking water induced similar lacrimal IgA.
responses.