This document discusses influenza pandemics. It defines an influenza pandemic as a new influenza virus emerging and spreading globally, with most people having no immunity. It notes some key influenza pandemics like the 1918 Spanish Flu that killed 50 million people. It describes symptoms and how influenza spreads through the air. It also outlines efforts by organizations like WHO and CDC to monitor influenza globally, provide guidance to countries, and work to update vaccines to fight the virus.