TABLE 3

Susceptibility of H6N9AH/13 mutant viruses to NA inhibitors

VirusaOseltamivirZanamivir
IC50 (nM)bFold change in IC50cIC50 (nM)Fold change in IC50
wt H6N9AH/130.55 ± 0.062.31 ± 0.12
H6N9AH/13 119V35.13 ± 1.036411.79 ± 0.295
H6N9AH/13 222R29.62 ± 3.195424.11 ± 2.0110
H6N9AH/13 246T1.70 ± 1.00337.00 ± 1.2716
H6N9AH/13 292K>200>363123.26 ± 8.1353
  • a H6N9AH/13 viruses were rescued to introduce each of the single antiviral-resistant mutations, E119V, I222R, A246T, and R292K, in NA.

  • b IC50 denotes the concentration of NA inhibitors (oseltamivir and zanamivir) that reduces NA activity by 50% in the MU-NANA assay. Shown are means ± standard deviations from two independent assays run in duplicate wells.

  • c Fold change relative to the wt level.