1918 Influenza Pandemic
People waiting in line for face masks in San Francisco, California, 1918
Photograph by Hamilton Henry Dobbin, courtesy of the California State Library
1918: The Most Severe Pandemic in Modern History
The 1918 influenza pandemic was the most severe pandemic in recent history. While it is not clear where the virus first emerged, we now know that this pandemic was caused by an influenza A(H1N1) virus.
It is estimated that about 500 million people, one-third of the world’s population, became infected with the pandemic virus. The number of deaths was estimated to be at least 50 million worldwide with about 675,000 occurring in the U.S. Mortality was high in people younger than 5 years old, 20-40 years old, and 65 years and older. High mortality in healthy people, including those 20-40 years, was a unique feature of the pandemic.
As the pandemic swept across the U.S., public health agencies scrambled to respond to the disease. The influenza virus had yet to be discovered, and there were no effective medications or vaccines to prevent or treat influenza at that time. To protect themselves, people relied on non-medical interventions to control the spread of the disease.