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 |
For additional information on seasonal flu visit: http://www.hhs.gov/flu/.
