Although there have been sufficient characterization of the NA
of H3N2 virus, including its crystal structure and even detailed
information of epitopes recognized by antibodies the NA of H9N2 virusremains to be investigated. In the present study, we generated and
characterized mouse monoclonal antibodies (mAbs) against the
NA of a Eurasian H9N2 avian influenza virus, with an emphasis on
identifying NA residues that are critical for the binding by these
mAbs. This is the first antigenic mapping of the NA of H9N2 virus,
which may facilitate further investigation on its antigenic
structure.