Virus NA Inhibitor, IC50 (nM)1 Zanamivir Fold2 Oseltamivir Fold Peramivir Fold Laninamivir Fold t/T/H5N2 LAIV 0.71 4 0.15 1 0.18 4 1.06 7 VN/H5N2 LAIV 0.59 3 0.15 1 0.19 4 1.23 8 VN/H5N1-RG LAIV 0.28 1 0.07 0 0.14 3 0.16 1 A/California/07/2009(H1N1)pdm093 0.19 1 0.24 1 0.05 1 0.16 1 A/NorthCarolina/39/2009(H1N1)pdm094 0.22 1 176.73 736 20.47 409 0.27 1 1IC50-drug concentration inhibiting the viral neuraminidase enzyme activity by 50%; values are averages of all test results. 2Fold-difference compared to the IC50 of the reference sensitive virus; 3Reference oseltamivir-sensitive virus; A/California/07/2009 (H1N1) pdm09; 4Reference oseltamivir-resistant virus A/North Carolina/39/2009 A (H1N1)pdm09, H275Y.

Table 5: Assessment of influenza virus susceptibility to neuraminidase inhibitors in the fluorescent neuraminidase inhibition assay.