This year marks the 100th anniversary of the great influenza pandemic of 1918. Between 50 and 100 million people are thought to have died, representing as much as 5 percent of the world’s population. Half a billion people were infected.

Especially remarkable was the 1918 flu’s predilection for taking the lives of otherwise healthy young adults, as opposed to children and the elderly, who usually suffer most. Some have called it the greatest pandemic in history. Continue reading.