Few experiences cause more misery than fighting off the flu. Many people confuse the flu with the common cold since the symptoms are similar and include headache, sore throat, stuffy nose, dry cough, and a general feeling of lethargy. Unlike the cold however, the flu is very often accompanied by a fever, muscle aches, and a more severe cough. Complications of the flu can include ear and sinus infections, bacterial pneumonia, dehydration, and worsening of chronic medical conditions such as congestive heart failure, diabetes, and asthma.

According to the Centers for Disease Control and Prevention (CDC), about every 10 years, the flu virus changes resulting in more severe cases of this illness. When large-scale outbreaks of the new virus occur it's called an epidemic. During the 2009-2010 flu season, the H1N1 virus-also known as the "swine flu"-caused a worldwide outbreak, or pandemic. This situation had not occurred for 40 years.

The best way to prevent the flu is to receive an annual flu shot. Flu season runs from October until April or May so September (or as soon as the shot becomes available) is an ideal time to be immunized. The CDC recommends either the shot or the nasal mist for all healthy persons over the age of six months. The shot contains killed viruses that won't cause the flu but enables the body to create antibodies that fight off infection if the live flu virus is encountered. The nasal mist has weakened live flu viruses and is offered only to healthy people between 2 and 49 years old.

We crunched the flu numbers for you:

  • 1: Number of days a person carrying the flu virus can be contagious before their symptoms appear. (In other words, it's possible to pass on the flu before you know you're sick.)
  • 5 to 7: Number of days a person with the flu and its symptoms is contagious.
  • 5 to 20: Percentage of U.S. residents who get the flu annually.
  • 200,000: Number of people hospitalized each year for flu-related complications.
  • 3,000 to 49,000: Number of flu-associated deaths over a 30-year period between 1976 and 2006.
  • 6: Number of feet from a sick person the flu virus can travel to be spread to a non-sick person. Symptoms start one to four days after the virus enters the body.
  • 2 to 8: Number of hours the flu virus can live and potentially infect a person after being deposited on a surface such as a school desk or counter top.
  • 1: Number of tablespoons of chlorine bleach added to one quart of water necessary to make an effective homemade disinfectant.
  • 3 to 5: Number of minutes the homemade disinfectant should stand on the dirty surface in order to kill germs.
  • 24: Number of hours you should stay home after your fever from the flu breaks, according to the American Academy of Family Physicians.
  • 130: Number of national influenza centers in 101 countries that currently conduct year-round surveillance of the flu and the disease trends.
  • 7 out of 10: Number of people protected from getting the flu from the flu shot in the 2007-2008 influenza season according to the results of a randomized study published by the CDC.
  • 60 Percent: Effectiveness of the 2010-2011 flu vaccine during the most recent influenza season.
  • 3: Number of flu viruses the flu shot protects against each year.
  • 132.1 million: Number of doses of the flu vaccine that were distributed as of February 2012.
  • 6: Number of manufacturers that made the 2011-2012 flu vaccine.
  • 6: Number of months it takes to produce large quantities of the influenza vaccine.
  • 79 million: Number of doses of thimerosal-free (preservative-free) influenza vaccine produced during the 2011-2012 season.




Key Facts About Influenza (Flu) & Flu Vaccine

Seasonal Influenza Questions & Answers

Update: Influenza Activity-United States, October 2, 2011-February 11, 2012.

National Public Radio (NPR)
How Many People Die From Flu Each Year? Depends How You Slice the Data

American Academy of Family Physicians
Colds and the Flu: H1N1 Influenza