Seasonal Flu: Happens annually and usually peaks between December and February

How often does it happen?

Pandemic Flu: Most people have little or no immunity because they have no previous exposure to the virus or similar viruses

Seasonal Flu: Usually some immunity from previous exposures and influenza vaccination

Pandemic Flu: Healthy people also may be at high risk for serious complications

Seasonal Flu: Certain people are at high-risk for serious complications (infants, elderly, pregnant women, extreme obesity and persons with certain chronic medical conditions)

Who is at risk for complications?

Pandemic Flu: Health care providers and hospitals may be overwhelmed Alternate care sites may be available to meet public and patient needs

Seasonal Flu: Health care providers and hospitals can usually meet public and patient needs

Pandemic Flu: Although the US government maintains a limited stockpile of pandemic vaccine, vaccine may not be available in the early stages of a pandemic Two doses of vaccine may be needed

Seasonal Flu: Vaccine available for annual flu season Usually, one dose of vaccine is needed for most people

Pandemic Flu: Antiviral supply may not be adequate to meet demand

Seasonal Flu: Adequate supplies of antivirals are usually available

How many people could get sick and suffer complications?

Seasonal Flu: Rates of medical visits, complications, hospitalizations and death can vary from low to high

CDC estimates that flu-related hospitalizations since 2010 ranged from 140,000 to 710,000, while flu-related deaths are estimated to have ranged from 12,000 to 56,000.