A(H7N9) Amantadine and Rimantadine Resistance

As noted by the Center for Disease Control, USA (CDC), although A(H7N9) is not currently spreading human-to-human, the disease is often severe and has a high mortality rate and  there is no current vaccine for A(H7N9) influenza.[1] The only viable option for infected individuals is early treatment with antivirals. The CDC recommends early antiviral treatment with neuraminidase inhibitors, noting that laboratory research indicates that adamantane derivatives will not inhibit replication of A(H7N9) virus.

An article published behind a paywall in Antiviral Therapy by Chinese researchers entitled Inhibition of novel reassortant avian influenza H7N9 virus infection in vitro with three antiviral drugs, oseltamivir, peramivir and favipiravir confirms the CDC recommendations. [2] The authors note that A(H7N9) was resistant to amantadine and remantadine, but was sensitive to two neuraminidase inhibitors, oseltamivir, peramivir, and  the investigational drug, favipiravir (T-705). Notably, favipiravir (T-705)  has previously been suggested as a possible therapeutic agent for another novel avian influenza  -- A(H5N1). [3]

[1] Interim Guidance on the Use of Antiviral Agents for Treatment of Human Infections with Avian Influenza A (H7N9)

[2] Inhibition of novel reassortant avian influenza H7N9 virus infection in vitro with three antiviral drugs, oseltamivir, peramivir and favipiravir

[3] T-705 (favipiravir) activity against lethal H5N1 influenza A viruses

h/t tetano