Oral immunisation of chickens using cholera toxin B subunit and softigen^R as adjuvants results in high antibody titre in the egg yolk

Oral immunisation by gavage of laying hens with human immunoglobulin G (IgG) combined with a number of potential adjuvants was performed. The resulting immuno-specific egg yolk (IgY) antibodies were quantified by ELISA. The following adjuvants were tested: A Poly(lactide-co-glycolide) (PLG) microspheres, Cholera toxin B-subunit (CTB), CTB conjugated with glutaraldehyde, Dimethyl dioctadecyl ammonium bromide (DDA), and Softigen® (pegylated C8/C10 mono/di glyceride). Hens in a positive control group were immunised with human IgG in saline emulsified with an equal volume of Freund's Incomplete Adjuvant. High titres of immunospecific IgY antibodies against human IgG were recorded in the eggs from the chickens immunised orally with the antigen combined with glutaraldehyde conjugated CTB and in the chickens immunised with the antigen combined with Softigen®. The present results show that invasive technique related stress could be eliminated/reduced in polyclonal antibody producing animals.