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About Pandemics
A pandemic is a global disease outbreak. It is determined by how the disease spreads, not how many deaths it causes.
When a new influenza A virus emerges, a flu pandemic can occur. Because the virus is new, the human population has little to no immunity against it. The virus spreads quickly from person-to-person worldwide.
The United States is not currently experiencing a flu pandemic. If a pandemic occurs, the federal government will work to identify the cause and create a vaccine. Flu.gov will provide updates on the steps the federal government is taking to address the pandemic.
Characteristics and Challenges of a Flu Pandemic
- Rapid Worldwide Spread
- When a pandemic flu virus emerges, expect it to spread around the world.
- You should prepare for a pandemic flu as if the entire world population is susceptible.
- Countries may try to delay the pandemic flu’s arrival through border closings and travel restrictions, but they cannot stop it.
- Overloaded Health Care Systems
- Most people have little or no immunity to a pandemic virus. Infection and illness rates soar. A substantial percentage of the world’s population will require some form of medical care.
- Nations are unlikely to have the staff, facilities, equipment, and hospital beds needed to cope with the number of people who get the pandemic flu.
- Death rates may be high. Four factors largely determine the death toll:
- The number of people who become infected
- The strength of the virus
- The underlying characteristics and vulnerability of affected populations
- The effectiveness of preventive measures
- Past pandemics spread globally in two or sometimes three waves.
- Past pandemics spread globally in two or sometimes three waves.
- Inadequate Medical Supplies
- The need for vaccines is likely to be larger than the supply. Those at highest risk will likely get the vaccine first.
- Early in a pandemic, the need for antiviral medications is likely to be larger than the supply. Those at highest risk will likely get antiviral medications first.
- A pandemic can create a shortage of hospital beds, ventilators, and other supplies. Alternative sites, such as schools, may serve as medical facilities.
- Disrupted Economy and Society
- Travel bans, event cancellations, and school and business closings could have a major impact on communities and citizens.
- Caring for sick family members and fear of exposure could result in significant employee absenteeism.
Seasonal Flu versus Pandemic Flu
Pandemic Flu | Seasonal Flu |
---|---|
Rarely happens (three times in 20th century) | Happens annually and usually peaks in January or February |
People have little or no immunity because they have no previous exposure to the virus | Usually some immunity built up from previous exposure |
Healthy people may be at increased risk for serious complications | Usually only people at high risk, not healthy adults, are at risk of serious complications |
Health care providers and hospitals may be overwhelmed | Health care providers and hospitals can usually meet public and patient needs |
Vaccine probably would not be available in the early stages of a pandemic | Vaccine available for annual flu season |
Effective antivirals may be in limited supply | Adequate supplies of antivirals are usually available |
Number of deaths could be high (The U.S. death toll during the 1918 pandemic was approximately 675,000) | Seasonal flu-associated deaths in the United States over 30 years ending in 2007 have ranged from about 3,000 per season to about 49,000 per season. |
Symptoms may be more severe | Symptoms include fever, cough, runny nose, and muscle pain |
May cause major impact on the general public, such as widespread travel restrictions and school or business closings | Usually causes minor impact on the general public, some schools may close and sick people are encouraged to stay home |
Potential for severe impact on domestic and world economy | Manageable impact on domestic and world economy |