Table 2.
Zanamivir susceptibilities determined using the NA Star assay for the different influenza virus subtypes isolated by cell culture
| Virus subtype | IC50 (nM) in the following influenza seasona: |
Total no. of isolates | |||||
|---|---|---|---|---|---|---|---|
| 2006-2007 |
2007-2008 |
2008-2009 |
|||||
| Range | Mean ± SD | Range | Mean ± SD | Range | Mean ± SD | ||
| A/H1N1 | 0.21–19.49 | 1.96 ± 5.27 (13) | 0.08–289.2 | 7.88 ± 44.06 (82)b | 0.22–5.05 | 0.87 ± 0.78 (71) | 166 |
| A/H3N2 | 0.43–5.61 | 1.22 ± 0.65 (72) | NAc | NA (0) | 0.23–4.63 | 1.07 ± 0.79 (33) | 105 |
| B | 1.47–10.87 | 3.95 ± 1.67 (71) | 4.01–5.59 | 4.8 ± 1.12 (2) | 1.58–9.16 | 3.92 ± 1.45 (27) | 100 |
a
Data in parentheses represent numbers of isolates.
b
The mean IC50, excluding resistant viruses, was 0.96 ± 1.41 nM; see Table 3.
c
NA, not applicable.