Influenza C virus. Coloured transmission electron micrograph (TEM) of a group of influenza (flu) type C viruses. Influenza C is a contagious ortho- myxovirus, different in several ways to influenza type A & B. Here, in the yellow stained area are rounded and filamentous forms of the virus. Tiny spikes on the protein coat of the viruses are seen. Influenza C uniquely shows an hexagonal surface pattern. These spikes stick to host cells when the virus invades the respiratory system. A person infected with the influenza C virus acquires antibodies that provide immunity for life against this stable type of influenza. Negatively stained. Magnification: unknown.