1917 • [Illustration of a male and female with the number 54 under the female icon and 48 under the male icon] • United States enters World War I. U.S. life expectancy is 54 years of age for women and 48 years of age for men. 1918 • [Illustration of a male and female and an arrow pointing down, with the number 42 under the female icon and 36 under the male icon] • Spring and fall waves of influenza (”flu”) activity cause the average life expectancy in the United States to fall by 12 years. 1919 • [Illustration of a globe and arrows circling the globe] • Third wave of pandemic flu activity occurs. Pandemic subsides, but virus (H1N1) continues to circulate seasonally for 38 years. 1930 • [Illustration of a test tube] • First isolation of influenza, proving that flu is caused by a virus not a bacterium. 1957 • [Illustration of an influenza virus] • H2N2 flu virus emerges to trigger a pandemic, replacing the 1918 H1N1 pandemic virus. 1960 • [Illustration of a flu vaccine syringe] • The U.S. Public Health Service recommends annual flu vaccination for people at high risk of serious flu complications. 1968 • [Illustration of an influenza virus] • H3N2 flu virus emerges to trigger a pandemic, replacing H2N2 virus. 2005 • [Illustration of a DNA strand] • Genome of the 1918 pandemic flu virus is fully sequenced. 2009 • [Illustration of three people in a circle with arrows points from person to person] • H1N1 viruses distantly related to the 1918 virus emerge to trigger a pandemic. pandemic-flu-milestone-infographic.pdf

Stephen B. Thacker CDC Library collection