Viruses are not cells at all, so they are neither prokaryotes nor eukaryotes.
Influenza viruses are classified as orthomyxoviruses.
Influenza is not a cell.
Which is not a cell?
  * cigarettes
  * Chlorophyll
  * Leptospirosis
  * layers of fat
  * an object
  * anemia
  * all matter
  * influenza