A Historical Look at Pandemic Flu

Spanish Flu, 1918–1919

Illness from the 1918 flu pandemic, also known as the Spanish flu, came on quickly. Some people felt fine in the morning but died by nightfall.
Approximately 20 percent to 40 percent of the worldwide population became ill.
An estimated 50 million people died.
Nearly 675,000 people died in the United States.

Asian Flu, 1957–1958

In February 1957, a new flu virus was identified in the Far East. Immunity to this strain was rare in people younger than 65.
Vaccine production began in late May 1957 and was available in limited supply by August 1957.
By December, the outbreak ebbed but resurged in January of 1958.
Although not as devastating as the 1918 pandemic, about 69,800 people in the United States died.
The elderly had the highest rates of death.

Hong Kong Flu, 1968–1969

In early 1968, a new flu virus was detected in Hong Kong. The first cases in the U.S. were detected as early as September 1968.
The number of deaths between September 1968 and March 1969 was 33,800, making it the mildest flu pandemic in the 20th century.
The flu hit hardest in December when schoolchildren were on vacation, leading to a decline in flu cases.
Improved medical care and antibiotics effective for secondary bacterial infections were available, minimizing fatalities.

H1N1, 2009–2010

In the spring of 2009, a new flu virus spread quickly across the U.S. and the world. The first case of H1N1 (swine flu) was diagnosed on April 15, 2009.
By April 21, the Centers for Disease Control and Prevention (CDC) began work on a vaccine. On April 26, the U.S. government declared a public health emergency.
A total of 74 countries were affected by the pandemic.
During the outbreak, 80 million people were vaccinated against H1N1.
The CDC estimates that 43 million to 89 million people contracted the virus.
There were between 8,870 and 18,300 H1N1-related deaths.