The pathogenesis of this human disease is studied in ferrets.
The pathogenesis of this human disease is studied in ferrets. One drug that combats this disease prevents a certain protein from binding to sialic acid; that drug is oseltamivir. A recently-developed and annually-modified vaccine for this disease, uses live, inactivated orthomyxovirions, is trivalent, and is produced as a nasal spray. Antigenic drift of this virus's hemagglutinin and neuraminidase surface proteins is responsible for its high mutation rate, and those proteins give rise to serotype names like H5N1. For 10 points, identify this disease whose "Spanish" strain caused a 1918 pandemic, for which many people are vaccinated each winter. 
The pathogenesis of this human disease is studied in ferrets.
influenza [or Influenzavirus] 