To evaluate the anti-influenza virus activity of SMeFM for viruses showing reduced susceptibility to approved anti-influenza drugs, we quantified the antiviral activity of SMeFM for recent IAV strains that has an amino acid substitution of NA E119V (H3N2), NA H275Y (H1N1pdm09), and PA I38T (H1N1pdm09). This evidence concerns the gene XK and influenza.