When a chicken is immunized with a mammalian antigen, the antigen is more ‘foreign’. These differences result in a broader range of epitopes being recognized than would be by an immunized mammal. The outcome is increased immunogenicity and specificity of response.
The advantages of IgY antibodies:
- High avidity: Most mammalian proteins exhibit enhanced immunogenicity in chickens than in mammals due to phylogenetic distance and thus raise antibodies of higher avidity. This also makes production of antibodies against conserved mammalian proteins more successful in chicken than in mammals.
- High specificity: In comparison to mammalian IgG, chicken IgY has less cross reactivity with mammalian proteins hence provide better specificity.
- Low background: IgY and IgG are structurally different in the Fc region, IgY does not bind to IgG Fc receptors and causes less false positive staining.
- Non-invasive: The method of antibody production is non-invasive as it is produced and purified from egg yolk.
- High yield: Chicken immunization requires low quantities of antigen to obtain high and long lasting IgY titre in the egg. The available quantity of a given antibody is considerably increased through repeated egg laying from the same hen.
- Stability: Egg yolk antibodies are stable over time. IgY antibodies have been stored for over 10 years at 4 degrees C without any significant loss in antibody activity. Chicken antibodies have also retained their activity after 6 months room temperature or 1 month at 37 degrees C.