Hamilton, ON (July 9, 2013) - Three waves of the deadliest influenza pandemic in history, known as the Spanish flu, hit England and Wales in 1918, just as World War 1 was coming to an end.
Why flu arrives in multiple waves like this is the focus of a study by McMaster University researchers who discovered three contributing factors: the closing and opening of schools, temperature changes and – most importantly – changes in human behavior.