Before there was swine flu...
The H1N1 flu virus is estimated to have killed more than 4,000 in the United States and many more worldwide in the 2009-2010 flu season, causing the first global flu pandemic in over 40 years.
Vaccines are now available that give combined protection against H1N1 and the seasonal flu.
Overall, this outbreak was relatively minor compared to past pandemics. In this slideshow, we revisit the century's worst flu pandemics—and false alarms.
« During a 1939 flu scare, a baby wears a polite message to keep sick people away.
Spanish flu (1918)
The 2009–2010 H1N1 pandemic paled in comparison to the Spanish flu of 1918–1919.
Helped along by the movement of troops during World War I, the virus infected 20% to 40% of the world’s population and killed an estimated 50 million, including up to 675,000 in the United States alone. (The virus earned its name from a rash of deaths in Spain, but its actual origin remains unclear.) In the end, more than three times as many people died from the flu as died in the war.
« Seattle policemen wear protective face masks during the 1918 pandemic.
Asian flu (1957)
A lethal new strain of influenza originated in the Far East in early 1957. After this so-called Asian flu spread stateside on Navy ships, outbreaks occurred across the United States throughout the summer. By August, a vaccine for the flu was being rationed and Time magazine had warned its readers that the virus “may strike 15 million to 30 million people.” An epidemic of that scale never materialized, though Asian flu did wreak havoc in schools and among the elderly. In all, nearly 70,000 Americans and 2 million people worldwide are believed to have died.
« A health officer at the University of Illinois surveys a hockey rink filled with hundreds of cots awaiting Asian flu cases.
Hong Kong flu (1968)
After spreading slowly through Asia, this new strain of flu hit the West Coast of the United States in the fall of 1968. Five hundred people in the tiny town of Needles, Calif., became sick, and the virus gradually spread through the western states and the rest of the country.
Fewer than 40,000 Americans died of Hong Kong flu. The casualties could have been far worse, but health officials were more prepared this time around. Some experts believe that the 1957 Asian flu may also have provided some immunity to the population.
« In a 1968 photograph, singer Vera Palm wears a "climate mask" to protect her voice from the flu.
Photo: Gerald R. Ford Library
Swine flu (1976)
Swine flu isn’t new. In 1976, a strain of the flu broke out on the Army base at Fort Dix, N.J. More than 200 soldiers were infected, including one who died from a bout of pneumonia caused by the virus. Fearing a pandemic, the federal government ordered a nationwide immunization drive that ultimately vaccinated 40 million Americans. Shortly after the program kicked into gear, however, reports emerged of Guillain-Barré syndrome (GBS), a serious disease of the nervous system, in a small but significant number of people who had been immunized. More than 30 people died from GBS, yet swine flu was never found outside of Fort Dix.
« President Gerald Ford is immunized during the 1976 swine-flu scare.
Avian flu (1997)
Typically found in poultry, avian (or bird) flu crossed over into humans in Hong Kong in 1997, causing six deaths. Bird flu reappeared in Asia in 2003 and prompted fears of a pandemic when it eventually turned up in Africa and the Middle East. In 2005, a United Nations health official warned that the virus could kill up to 150 million worldwide.
Fortunately these fears weren't realized. A pandemic was never declared, and health officials determined that the flu does not spread easily from person to personand it definitely can't be spread by eating fully cooked chicken or turkey. No cases in humans have been reported in the United States.
« Government scientists tested birds for avian flu in California in 2006.
H1N1 flu (2009)
In the spring of 2009, H1N1 erupted in Mexico and spread quickly across the globe. By Junewhen the World Health Organization declared a pandemicH1N1 flu had shown up in all 50 states; by September, cases had been confirmed in nearly every country in the world.
Fortunately, H1N1 flu has not left the trail of destruction that experts feared.
« A young woman distributes hand-sanitizing wipes in New York City's Times Square in May 2009.