TABLE 1.

Sensitivities of recombinant A/Wuhan/359/95 (H3N2) influenza viruses to NAIs

VirusNA inhibition assaya (nM, mean IC50 ± SD)Virus reduction assayb (μM, mean EC50 ± SD)
Oseltamivir carboxylateZanamivirMDCKMDCK-SIATI
Oseltamivir carboxylateZanamivirOseltamivir carboxylateZanamivir
RG WT0.8 ± 0.12.4 ± 0.19.5 ± 0.655.3 ± 2.20.04 ± 0.010.06 ± 0.01
RG E119V-NA209.0 ± 6.82.1 ± 0.193.5 ± 9.249.6 ± 8.30.43 ± 0.180.05 ± 0.02
RG R292K-NA>30,00031.5 ± 9.3810 ± 8832.7 ± 4.5c
  • a NA inhibition assays were done with MUNANA as the substrate at a final concentration of 100 μM. Values were obtained from three independent determinations.

  • b The assay was performed with MDCK or MDCK-SIAT1 cells infected with virus at an MOI of 0.01 PFU/cell. Values were obtained from triplicate wells in two independent experiments.

  • c —, not applicable. The RG R292K-NA virus showed a severe growth defect in MDCK-SIAT1 cells both in the absence and in the presence of NAIs.