 The global mortality rate from the 1918 / 1919 pandemic is not known, but an estimated 10 % to 20 % of those who were infected died. With about a third of the world population infected, this case-fatality ratio means 3 % to 6 % of the entire global population died. Influenza may have killed as many as 25 million people in its first 25 weeks. Older estimates say it killed 40 – 50 million people, while current estimates say 50-100 million people worldwide were killed.
