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Respiratory Viruses

This guide covers viral respiratory infections, including influenza, RSV, and other influenza-like illnesses (ILI)

What is Pandemic Influenza?

Pandemic Influenza

An influenza pandemic is a global outbreak of a new influenza A virus. Pandemics happen when new (novel) influenza A viruses emerge which are able to infect people easily and spread from person to person in an efficient and sustained way.

How is Pandemic Influenza Different from Seasonal Influenza?
  Seasonal Influenza Pandemic Influenza

How often does it happen?

Happens annually and usually peaks between December and February

Rarely happens (three times in 20th century)

Will most people be immune?

Usually some immunity from previous exposures and influenza vaccination

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

Who is at risk for complications?

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

Healthy people also may be at high risk for serious complications

Where can I get medical care?

Health care providers and hospitals can usually meet public and patient needs

Health care providers and hospitals may be overwhelmed

Alternate care sites may be available to meet public and patient needs

Will a vaccine be available?

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

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

Will antivirals be available?

Adequate supplies of antivirals are usually available

Antiviral supply may not be adequate to meet demand

How many people could get sick and suffer complications?

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.

Rates of medical visits, complications, hospitalizations and death can range from moderate to high

Number of deaths could be much higher than seasonal flu (e.g. The estimated U.S. death toll during the 1918 pandemic was approximately 675,000)

What impact will it have on schools and workplaces?

Usually causes minor impact on the general public, some schools may close and sick people are encouraged to stay home

Manageable impact on domestic and world economies

May cause major impact on the general public, such as travel restrictions and school or business closings

Potential for severe impact on domestic and world economies

Pandemic Influenza Resources