We tested the neuraminidase drug sensitivity of clade 1 and clade 2 influenza A virus (H5N1). All viruses
demonstrated similar sensitivity to zanamivir, but compared to the 2004 clade 1 viruses, the Cambodian
2005 viruses were 6-fold less sensitive and the Indonesian clade 2 viruses were up to 30-fold less
sensitive to oseltamivir.

Reduced Sensitivity of Influenza A (H5N1) to Oseltamivir.pdf