What is influenza (flu)?

Influenza, also known as the flu, is an illness that causes fever, headache, tiredness,  cough, sore throat, headache, nasal congestion and body aches.  It is usually spread from person to person by coughing and sneezing.   

Influenza is different from the common cold.  It usually begins suddenly and can put you in bed for a number of days.  Most people who get influenza will recover in one to two weeks, but some people can develop very serious illnesses such as pneumonia, be hospitalized or die.  Very young children, people age 65 years and older and anyone with a chronic medical problem are most at risk of serious illness.

What can you do to protect yourself from the flu?

Influenza is caused by a virus, so antibiotics (such as penicillin) do not work to cure it. The best way to prevent the flu is to get a flu vaccination each year, before flu season.

The flu vaccine is different each year because the viruses change.  The vaccine usually protects against three virus types: two A types and one B type. 

There are two types of vaccines:

• The "flu shot" – an inactivated vaccine (containing killed virus) that is given with a needle. The flu shot is approved for use in people older than 6 months of age, including healthy people and people with chronic medical conditions.
  
  
• The nasal-spray flu vaccine, a vaccine made with live, weakened flu viruses that do not cause the flu (sometimes called LAIV for “Live Attenuated Influenza Vaccine”). LAIV is approved for use in healthy people 5 years to 49 years of age who are not pregnant.

October or November is the best time to get your flu vaccine, but getting vaccinated in December or even later can still be helpful.  Flu season can begin as early as October and end as late as May.

What about antiviral medicines?

Antiviral medications can be effective for the treatment of influenza.  Four licensed influenza antiviral agents are available in the United States: amantadine, rimantadine, zanamivir and oseltamivir.  On the basis of antiviral testing results, the Centers for Disease Control and Prevention (CDC) and the Advisory Committee on Immunization Practices (ACIP) recommend that neither amantadine nor rimantadine be used for the treatment of influenza A in the United States.  Oseltamivir or zanamivir can be prescribed if antiviral treatment of influenza is indicated.  Additional information about the prevention and control of influenza is available at http://www.cdc.gov/flu.

Last  Updated: 01/30/07