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