What is IgY?

IgY (Immunoglobulin-Y) is the most common type of antibody produced by the B cells in birds, reptiles and amphibians, and has a long history of being used as passive immunity therapeutic agents in humans and animals. Chicken (hen) IgY has been, and continues to be the most widely studied.

Similarly to human IgG, IgY is produced at high concentrations in serum, and accumulates in high concentrations in egg yolk to provide offspring with effective humoral immunity. High concentrations of antibodies making them ideal source for a variety of human and animal health applications. Clinical evidence demonstrates that when consumed, they are not rejected by the human immune system and the antibodies remain in the digestive tract.

Immunoglobulin Y (IgY) has an equivalent
functional role to both mammalian IgG and IgE

Similar to IgG, avian IgY mediates general protective immune responses and it also mediates
the anaphylactic response typically associated with mammalian IgE.*

Several characteristics make IgY well suited for human use. For instance, IgY does not induce specific resistance because it targets multiple antigens; IgY has greater binding avidity to target antigens than mammalian IgG; IgY directed against conserved mammalian proteins is easier to produce than IgG because of the evolutionary distance between mammals and birds; and IgY does not bind to mammalian Fc receptors or induce an IgE response, minimizing the risk of allergic reactions and administration-related inflammation.

IgY antibodies created to target specific antigens are intended to have a localized, highly target-specific, predictable, and efficient antigen-antibody interaction. Antigens can be complex antigens from viruses, bacteria or parasites or single antigens from proteins, polysaccharides, peptides, and nucleic acids.  For example, IgY antibodies can minimize the resistance seen with the use of antibiotic use to treat bacterial infections since the IgY antibodies are directed to specific and usually multiple antigens on the bacteria, which require multiple genes for their synthesis and it is, therefore, difficult for the bacteria to mutate to become resistant to the IgY antibodies. Specific IgY antibodies have also been used to diagnose viral, bacterial, parasitic infections as well as cancers through targeting of specific antigens.

Attributes and Advantages

IgY antibodies created to target specific antigens are intended to have a localized, highly target-specific, predictable, and efficient antigen-antibody interaction.

Proposed mechanisms of action for Specific IgY antibodies:

• Inhibition of bacterial and viral adhesion to host cell surface
• Suppression of bacterial colonization and viral cell-to-cell spread
• Bacterial agglutination resulting in microbial immobilization and being flushed out of the body
• Inhibition of enzyme activity
• Neutralization of toxin activity

When compared to vaccines, passive immunotherapy using specific IgY offers distinct advantages:

• Immediate and local onset of action
• High antibody-antigen affinity
• Applicability to a broader range of patients from infants to adults and  immunodeficient/immunocompromised patients
• Non-toxic and is Generally Regarded as Safe (GRAS)

Advantages of specific IgY relative to antibiotics:

• Natural and safe without toxic tissue residues
• Avoids environmental contamination with synthetic chemical drug
• Does not induce specific pathogenic microorganism resistance since it is directed to multi-antigenic targets which need multiple genes for their synthesis
• Highly specific in its reactivity and controls only targeted pathogens without affecting normal bacterial flora
• Does not induce adverse side effects unlike synthetic drugs