How Does Seasonal Flu
Differ From Pandemic Flu?

Seasonal Flu

 

Pandemic Flu

Outbreaks follow predictable seasonal patterns; occurs annually, usually in winter, in temperate climates   Occurs rarely (three times in 20th century - last in 1968)
Usually some immunity built up from previous exposure   No previous exposure; little or no pre-existing immunity
Healthy adults usually not at risk for serious complications; the very young, the elderly and those with certain underlying health conditions at increased risk for serious complications   Healthy people may be at increased risk for serious complications
Health systems can usually meet public and patient needs   Health systems may be overwhelmed
Vaccine developed based on known flu strains and available for annual flu season   Vaccine probably would not be available in the early stages of a pandemic
Adequate supplies of antivirals are usually available   Effective antivirals may be in limited supply
Average U.S. deaths approximately 36,000/yr   Number of deaths could be quite high (e.g., U.S. 1918 death toll approximately 500,000)
Symptoms: fever, cough, runny nose, muscle pain. Deaths often caused by complications, such as pneumonia.   Symptoms may be more severe and complications more frequent
Generally causes modest impact on society (e.g., some school closing, encouragement of people who are sick to stay home)   May cause major impact on society (e.g. widespread restrictions on travel, closings of schools and businesses, cancellation of large public gatherings)
Manageable impact on domestic and world economy   Potential for severe impact on domestic and world economy