TY - JOUR AU - Nguyen, Ha AU - Nguyen, Tung AU - Mishin, Vasiliy AU - Sleeman, Katrina AU - Balish, Amanda AU - Jones, Joyce AU - Creanga, Adrian AU - Marjuki, Henju AU - Uyeki, Timothy AU - Nguyen, Dang AU - Nguyen, Diep AU - Do, Hoa AU - Klimov, Alexander AU - Davis, Charles AU - Gubareva, Larisa T1 - Antiviral Susceptibility of Highly Pathogenic Avian Influenza A(H5N1) Viruses Isolated from Poultry, Vietnam, 2009–2011 T2 - Emerging Infectious Disease journal PY - 2013 VL - 19 IS - 12 SP - 1963 SN - 1080-6059 AB - We assessed drug susceptibilities of 125 avian influenza A(H5N1) viruses isolated from poultry in Vietnam during 2009–2011. Of 25 clade 1.1 viruses, all possessed a marker of resistance to M2 blockers amantadine and rimantadine; 24 were inhibited by neuraminidase inhibitors. One clade 1.1 virus contained the R430W neuraminidase gene and reduced inhibition by oseltamivir, zanamivir, and laninamivir 12-, 73-, and 29-fold, respectively. Three of 30 clade 2.3.4 viruses contained a I223T mutation and showed 7-fold reduced inhibition by oseltamivir. One of 70 clade 2.3.2.1 viruses had the H275Y marker of oseltamivir resistance and exhibited highly reduced inhibition by oseltamivir and peramivir; antiviral agents DAS181 and favipiravir inhibited H275Y mutant virus replication in MDCK-SIAT1 cells. Replicative fitness of the H275Y mutant virus was comparable to that of wildtype virus. These findings highlight the role of drug susceptibility monitoring of H5N1 subtype viruses circulating among birds to inform antiviral stockpiling decisions for pandemic preparedness. KW - Influenza KW - viruses KW - H5N1 KW - Oseltamivir KW - H275Y KW - antiviral KW - zoonoses KW - Vietnam DO - 10.3201/eid1912.130705 UR - https://wwwnc.cdc.gov/eid/article/19/12/13-0705_article ER - End of Reference