blue and white rubber ball

This image depicts a 3D generated rendering of a whole influenza (flu) virus with a light grey surface membrane, set against a black background. The virus’ surface proteins, hemagglutinin (HA) and neuraminidase (NA), are depicted in light and dark blue, respectively. HA is a trimer, which is comprised of three subunits, while NA is a tetramer, which is comprised of four subunits, with a head region resembling a 4-leaf clover. Illustrator: Dan Higgins