Viral flu is a viral infection. It’s passed on when people breathe in liquid droplets containing the influenza virus that have been sneezed or coughed into the air. The virus can cause infections all year round. Virus is a germ that is smaller than a bacteria. Viruses are encapsulated by a protective coating so they are more difficult to kill than bacteria. They are harder to treat because they are not susceptible to antibiotics like bacteria are because of their protective coating.