|ANIME DEBUT||Episode 3|
|MANGA DEBUT||Chapter 3|
Influenza virus (インフルエンザウイルス Infuruenza Uirusu?) is the cause of influenza. In virus classification, influenza viruses are RNA viruses that make up four of the seven genera of the family Orthomyxoviridae.
Cells that had been infected by influenza virus looks like a zombie. Those cells are wearing a "hat" that resembles the virus.