This patent application discloses siRNA sequences against the constant region of the influenza virus nucleoprotein gene comprising: TABLE-US-00001 Sense strand: 5' UGAAGGAUCUUAUUUCUUCdTdT 3' (SEQ ID NO: 1) Anti sense 3' dTdTACUUCCUAGAAUAAAGAAG 5' strand: (SEQ ID NO: 2) or Sense strand: 5' UGAAGGAUCUUAUUUCUUCGGdTdT 3' (SEQ ID NO: 3) Anti sense 3' dTdTACUUCCUAGAAUAAAGAAGCC 5' strand: (SEQ ID NO: 4) or Sense strand: 5' GGAUCUUAUUUCUUCGGAGACdTdT 3' (SEQ ID NO: 5) Anti sense 3' dTdTCCUAGAAUAAAGAAGCCUCUG 5' strand: (SEQ ID NO: 6) said sequences being inhibitory against influenza virus in animals including humans. The invention further includes one or more of said siRNA sequences in the form of an aqueous suspension suitable for nasal inhalation. Still further, the invention includes one or more of said siRNA sequences in the form of a plasmid expressing intracellularly in animals including humans. In another aspect, the invention includes one or more of said siRNA sequences in the form of an AAV vector adapted to express intercellularly and establish a permanent inhibitory effect against influenza virus by integrating to the cellular chromosome of animals including humans. The invention also includes the administration to an animal including humans, in a therapeutically effective amount, at least one of said siRNA sequences.