. 2008 Jul 14;52(9):3284–3292. doi: 10.1128/AAC.00555-08

TABLE 5.

Characterization of extreme and mild outliers detected among influenza B viruses from three previous seasons

Season	Strain	Mean IC₅₀ ± SD (nM)^a		Outlier(s)/drug(s)^b	NA mutation^c	Accession no.
Season	Strain	Oseltamivir	Zanamivir	Outlier(s)/drug(s)^b	NA mutation^c	Accession no.
2004-2005	B/Hong Kong/36/2005	1,778.25 ± 729.78^d	154.85 ± 47.47^d	E/O, E/Z	R371K	EU879085
2004-2005	B/Michigan/20/2005	10.80 ± 2.90^e	1.54 ± 0.27	M/O	H274Y	CY015375
2004-2005	B/California/5/2005	10.48 ± 1.62	8.65 ± 1.46	M/O	I222T	EU879086
2004-2005	B/California/4/2005	8.60 ± 1.93	3.73 ± 1.72	M/O	T325I	EU879084

Mean IC₅₀ ± SD values were calculated from data collected from at least three independent experiments.

E, extreme; M, mild; O, oseltamivir (IC₅₀ values of >7.47 nM); Z, zanamivir (IC₅₀ values of >11.29 nM).

Boldface type indicates the mutation in the NA active site.

A 407-fold increase in IC₅₀ to oseltamivir and a 29-fold increase in IC₅₀ to zanamivir compared to the IC₅₀ values of the matching virus B/Hong Kong/45/2005 (accession no. ISDN127249).

A 4-fold increase in IC₅₀ to oseltamivir compared to that of the matching virus B/Illinois/47/2005 (accession no. CY15376).