The present invention provides novel antigens of an allergy to egg, methods and kits for diagnosing an allergy to egg, pharmaceutical compositions comprising such an antigen, eggs or processed products of egg in which such an antigen is eliminated or reduced, birds that deliver such eggs or are born from such eggs, a method for producing processed products of egg in which such an antigen is eliminated or reduced, and a tester for determining the presence or absence of an egg antigen in an object of interest. The present invention also relates to polypeptides comprising an epitope of an antigen, kits, compositions and methods for diagnosing an allergy, comprising such a polypeptide, pharmaceutical compositions comprising such a polypeptide, and raw materials or processed products in which an antigen comprising such a polypeptide is eliminated or reduced. The present invention further relates to a tester for determining the presence or absence of an antigen in an object of interest.
