Viral genome RNA degradation by sequence-selective, nucleic-acid hydrolyzing antibody inhibits the replication of influenza H9N2 virus without significant cytotoxicity to host cells

► NP-encoding vRNA (NP-vRNA) of H9N2 virus is targeted for degradation by antibody. ► NP25 antibody selectively hydrolyzes a 18-nt ssDNA derived from the NP-vRNA. ► The expression of NP25 does not show any significant cytotoxicity to the host cells. ► NP25 potently inhibits the replication of H9N2 virus in the stable cell lines. ► NP25 selectively hydrolyzes the targeted NP-vRNA in the stable cell lines.