A kind of polypeptide not more less than 100 amino acid is provided, which polypeptide includes that one or more sequences have any sequence number 1-6 of attack of at least 60% homology or have the epitope of 7 or more amino acid including two or more, each epitope attack at least sequence of 60% homology it is any those with the identical epitope of sequence number 1-6 length. Wherein, polypeptide is vertebrate expression major histocompatibility complex (MHC) allele of immunogenicity, and wherein the polypeptide is not complete influenza virus protein.
