TECHNICAL FIELD The present invention relates to a marker for detecting highly pathogenic virus and its use, and more specifically, a marker for detecting highly pathogenic virus containing a protein variant in which the 68th and 69th amino acids of PB1-F2 protein are substituted. A composition for detecting a highly pathogenic virus comprising a preparation for measuring the protein variant, a detection kit comprising the same, a method for detecting a highly pathogenic virus comprising the step of measuring the protein variant, 68th and 69th The present invention relates to an antiviral composition against influenza A virus, which comprises, as an active ingredient, a PB1-F2 protein with an amino acid substitution and a DDX3 binding inhibitor, and a method for screening an antiviral substance against influenza A virus. In the present invention, as a result of first elucidating the correlation between the 1918 PB1-F2 protein and the high pathogenicity of the virus and its molecular mechanism, the 68th and 69th amino acids were substituted in the influenza virus PB1-F2 protein sequence. The resulting protein mutant can be used as a marker for detecting a highly pathogenic virus, and by measuring the mutant, a highly pathogenic virus can be effectively detected. In addition, the mechanism by which the PB1-F2 protein variant newly elucidated in the present invention avoids the innate immune response of viruses provides a new understanding for the development of antiviral preparations, and the antiviral composition according to the present invention Can be usefully utilized in the development of antiviral therapeutic formulations. [Selection diagram] Fig. 10本発明は、高病原性ウイルス検出用マーカーおよびその用途に関し、より具体的には、ＰＢ１－Ｆ２タンパク質の６８番目および６９番目のアミノ酸が置換されたタンパク質変異体を含む高病原性ウイルス検出用マーカー、前記タンパク質変異体を測定する製剤を含む高病原性ウイルス検出用組成物およびこれを含む検出キット、前記タンパク質変異体を測定する段階を含む高病原性ウイルスの検出方法、６８番目および６９番目のアミノ酸が置換されたＰＢ１－Ｆ２タンパク質とＤＤＸ３の結合阻害剤を有効成分として含むインフルエンザＡウイルスに対する抗ウイルス用組成物、およびインフルエンザＡウイルスに対する抗ウイルス物質のスクリーニング方法に関する。本発明では、１９１８ ＰＢ
