Influenza: What you need to know

What is influenza(flu)?

Influenza is caused by the influenza virus, which spreads from person to person through coughing or sneezing. It infects through the nose, throat, windpipe and lungs. The virus is highly contagious and can spread from one person to another by coughing, sneezing or talking. Other illnesses can have the same symptoms and are often mistaken for influenza. But only the influenza virus can cause influenza. Influenza infections occur between October and April of each year.

What of symptoms of influenza?

Typical symptoms of influenza include fever, chills, muscle aches, congestion, cough, runny nose and difficulty breathing. Other viruses can cause symptoms similar to influenza. Anyone can get influenza. For most people, it lasts only a few days. Some people get much sicker. Influenza can lead to pneumonia and can be dangerous for people with heart or breathing conditions. It can cause high fever and seizures in children.

Can influenza be life-threatening?

Yes. Every year in the United States approximately 200,000 people are hospitalized and 36,000 people die from complications of influenza infection. Most of the people who died are older than 65, but many of those who are hospitalized are younger than 5. Children hospitalized because of influenza usually have high fever, wheezing, croup or pneumonia. Because influenza is a virus, it can't be successfully treated with antibiotics.

Is are a vaccine to prevent influenza?

Yes. There are two different influenza vaccines. The "inactivated" influenza vaccine is made by taking influenza virus, growing them in eggs, and purifying them. This vaccine is given as a shot.

The "live,weakened" influenza vaccine (FluMist) is made so it cannot grow in the lungs. However because the weakened viruses can grow in the lining of the nose, they induce an excellent protective immune response. FluMist is also made by growing the virus in eggs. This vaccine is given as a nasal spray. Both vaccines contained the 3 different strains of influenza virus likely to cause disease this year.

Why you have to get influenza vaccine every year?

Influenza virus is given every year because the strains of influenza viruses that circulate every year are different. Influenza is unique in its ability to change the proteins that reside on the surface of the virus. These changes mean that people naturally infected or immunized one year are usually not protected the next year.

Are influenza vaccine safe?

Yes. The inactivated influenza vaccine can cause pain, redness or tenderness at the site of injection. It can also cause muscle aches and low grade fever, but because the vaccine viruses are completely inactivated, they cannot possibly cause influenza.

The influenza vaccine does have one side effects that can be quite serious. Because it is made in eggs, the vaccine contain small quantities of egg proteins. People allergic to eggs can have a severe, and rarely fatal, allergic reaction. This reaction happens in about one of every 2 million people who received the vaccine. For this reason, people who are allergic to eggs should not receive the influenza vaccine.

Do the influenza vaccine work?

Yes. The influenza vaccine will prevent about 70 to 90% of people who received it from developing moderate to severe influenza infection.

When should you get the influenza vaccine?

The influenza vaccine is optimally given in October and November, just before the influenza season starts. However it can be given as early as September and continued through the influenza season, as late as March.

Who should get the influenza vaccine?

The inactivated influenza vaccine is recommended for people at highest risk for severe complications caused by influenza virus. Those at highest risk include: People of all ages with asthma; people of all ages with chronic diseases of the lungs, heart or kidneys; people older than 50; pregnant women; and healthy children between 6 months and 5 years of age. Children less than 9 years of age who have never received influenza vaccine required two doses.

However, all people, no matter how healthy, are at some risk of developing severe and even fatal influenza infections. It is reasonable for anyone who wants to reduce their chance of getting influenza to get a flu shot. The nasal FluMist vaccine is currently available for healthy people between 5 and 49 years of age and has the advantage of inducing an excellent immune response without requiring a shot although it is significantly more expensive.

Who should get the vaccine?

Some people should not get the inactivated influenza vaccine or should wait before getting it. People with a severe egg allergy should not get the vaccine. A severe allergy to any vaccine component is also a reason not to get the vaccine. If you had a severe reaction after a previous dose of influenza vaccine, tell your doctor. Life-threatening allergic reactions from vaccines are very rare. If they do occur, it is within a few minutes to a few hours after the shot. Also tell your doctor if he ever had Guillain-Barré syndrome. You may be able to get the vaccine, but your doctor should help to make that decision. People who are moderately or severely ill should usually wait until they recover before getting flu vaccine. If you are ill, talk to your doctor or nurse about whether to reschedule a vaccination. People with a mild illness can usually get the vaccine without problem.

Should healthy children get the influenza vaccine?

Yes. There are two reasons that all healthy children between 6 months and 5 years of age should receive the influenza vaccine. First, influenza virus can kill children. In the epidemic of 2003- 2004, 152 children died from influenza infection; many were previously healthy and not in a high risk group. The following season, 2004-2005, about 75 children died from influenza. Second, people older than 65 are most likely to catch influenza virus from a young child. Therefore, immunizing children also prevents deaths in the elderly.

How can I get the influenza vaccine?

Family Health Center now has the vaccines available. You can receive the vaccine if you are visiting us for any reason. You can also receive the vaccine if you stop by our office at any time. If none of these options work for you, we encourage you to get the flu shot at any location where you see it advertised.

How can I learn more?

Ask your doctor or nurse. Call your local or state health department. You can also contact the centers for disease control and prevention (CDC) at 1-800-CDC-INFO or visit the CDC website at www.cdc.gov/flu.

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