Avian eggs are the largest source of major nutrients which consists of various types of proteins, fats, vitamins, growth factors and minerals
that are required for the developing embryo and also significant number of defence factors for protecting against many viral and bacterial
infections. It also consists of various biological substances in it that forms the basic unit of life. Chicken egg yolk contains antibodies called
Immunoglobulin Y (IgY) which is the major antibody present in birds, lungfish, amphibia and lungfish, playing a similar role like mammalian
antibody IgG. IgY antibodies are transferred from serum to egg yolk which was first demonstrated by Klemperer in 1893 . This review mainly
focuses on the applications of antigen-specific chicken egg yolk antibodies (IgY) in human therapeutics to protect against various bacterial
and viral infections and to maintain a good care for healthy respiratory, oral and digestive system which highlights the value of human health
importance and disease prevention and treatment effectively.