Provided by Centers for Disease Control and Prevention

What is Influenza (also called Flu)?

The flu is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness, and at times can lead to death. The best way to prevent this illness is by getting a flu vaccination each fall.

Every year in the United States, on average:

  • 5% to 20% of the population gets the flu;
  • more than 200,000 people are hospitalized from flu complications, and;
  • about 36,000 people die from flu.

Some people are at high risk for serious flu complications, such as older people, young children, and people with certain health conditions.

Symptoms of flu include:                                            

  • fever (usually high),
  • headache,
  • extreme tiredness,
  • dry cough,
  • sore throat,
  • runny or stuffy nose, and
  • muscle aches.
  • stomach symptoms, such as nausea, vomiting, and diarrhea, also can occur but are more common in children than adults

Complications of Flu

Complications of flu can include bacterial pneumonia, dehydration, and worsening of chronic medical conditions, such as congestive heart failure, asthma, or diabetes. Children may get sinus problems and ear infections.

How Flu Spreads

Flu viruses spread in respiratory droplets caused by coughing and sneezing. They usually spread from person to person, though sometimes people become infected by touching something with flu viruses on it and then touching their mouth or nose. Most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 days after getting sick. That means that you can pass on the flu to someone else before you know you are sick, as well as while you are sick.

Preventing the Flu: Get Vaccinated

The single best way to prevent the flu is to get a flu vaccination each fall. There are two types of vaccines:

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, 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.

About two weeks after vaccination, antibodies develop that protect against influenza virus infection. Flu vaccines will not protect against influenza-like illnesses caused by other viruses.

When to Get Vaccinated

October or November is the best time to get vaccinated, but you can still get vaccinated in December and later. Flu season can begin as early as October and last as late as May.

Who Should Get Vaccinated?

In general, anyone who wants to reduce their chances of getting the flu can get vaccinated. However, certain people should get vaccinated each year. They are either people who are at high risk of having serious flu complications or people who live with or care for those at high risk for serious complications. People who should get vaccinated each year are:

  1. People at high risk for complications from the flu:
    • People 65 years and older;
    • People who live in nursing homes and other long-term care facilities that house those with long-term illnesses;
    • Adults and children 6 months and older with chronic heart or lung conditions, including asthma;
    • Adults and children 6 months and older who needed regular medical care or were in a hospital during the previous year because of a metabolic disease (like diabetes), chronic kidney disease, or weakened immune system (including immune system problems caused by medicines or by infection with human immunodeficiency virus [HIV/AIDS]);
    • Children 6 months to 18 years of age who are on long-term aspirin therapy. (Children given aspirin while they have influenza are at risk of Reye syndrome.);
    • Women who will be pregnant during the influenza season;
    • All children 6 to 23 months of age;
    • People with any condition that can compromise respiratory function or the handling of respiratory secretions (that is, a condition that makes it hard to breathe or swallow, such as brain injury or disease, spinal cord injuries, seizure disorders, or other nerve or muscle disorders.)

 

  1. People 50 to 64 years of age. Because nearly one-third of people 50 to 64 years of age in the United States have one or more medical conditions that place them at increased risk for serious flu complications, vaccination is recommended for all persons aged 50 to 64.
  2. People who can transmit flu to others at high risk for complications. Any person in close contact with someone in a high-risk group (see above) should get vaccinated. This includes all health-care workers, household contacts and out-of-home caregivers of children 6 to 23 months of age, and close contacts of people 65 years and older.

Is CDC recommending that flu shots go to "priority groups," as was recommended last season?

To ensure that those who are at highest risk of complications from influenza have access to vaccine this season, CDC recommends that people in certain priority groups receive inactivated influenza vaccine (i.e., the "flu shot") until October 24, 2005:

  • people aged 65 years and older, with and without chronic health conditions
  • residents of long-term care facilities
  • people aged 2-64 years with chronic health conditions
  • children aged 6-23 months
  • pregnant women
  • health-care personnel who provide direct patient care
  • household contacts and out-of-home caregivers of children less than 6 months of age

Beginning October 24, 2005, all persons can get a flu shot.

Use of the Nasal Spray Flu Vaccine

It should be noted that vaccination with the nasal-spray flu vaccine is always an option for healthy persons aged 5-49 years who are not pregnant. This vaccine is not subject to prioritization and can be given to healthy 5-49 year olds at any time.