Flu Information

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Flu FAQ

Q. What is influenza (flu)? A. Influenza (flu) is a virus that infects the nose, throat, windpipe and lungs. The virus is highly contagious and is spread from one person to another by coughing, sneezing or talking. Influenza infections occur between October and April of each year.

Q. What are the symptoms of influenza? A. Typical symptoms of influenza include fever, chills, muscle aches, congestion, cough, runny nose and difficulty breathing. Other viruses can cause symptoms similar to influenza. But, influenza virus is a more common cause of severe, fatal pneumonia.

Q, Can influenza be life-threatening? A. Yes. Every year in the United States approximately 200,000 people are hospitalized and 36,000 die from complications of influenza infection. Most of the people who die are older than 65, but many of those who are hospitalized are younger than 4. 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.

Q. Is there a vaccine to prevent influenza? A. Yes. There are two different influenza vaccines. The “inactivated” influenza vaccine is made by taking influenza viruses, growing them in eggs, purifying them and completely inactivating them with the chemical formaldehyde. This vaccine is given as a shot. The “live, weakened” influenza vaccine (FluMist) is made so that it cannot grow in the lining of the nose, they induce an excellent protective immune response. FluMist is also made by growing the viruses in eggs. The vaccine is given as a nasal spray. Both vaccines contain the three different strains of influenza viruses likely to cause disease that year.

Q. Why do you have to get an influenza vaccine every year? A. The influenza vaccine 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.

Q. Why get vaccinated? Influenza (“flu”) is a very contagious disease. It is caused by the influenza virus, which spreads from infected persons to the nose or throat of others. Other illnesses can have the same symptoms and are often mistaken for influenza. But only an illness caused by the influenza virus is really influenza. Anyone can get influenza, but rates of infection are highest among children. For most people, it lasts only a few days. It can cause: fever, cough, sore throat, headache, chills, muscle aches and fatigue. 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. Influenza kills about 36, 000 people each year in the United States.

Q. Are influenza vaccines safe? A. 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 live, weakened vaccine can cause mild congestion and runny nose. However, because the live, weakened vaccine has been modified so that it cannot grow in the lungs, it cannot possibly cause pneumonia. This influenza vaccine does have one side effect that can be quite serious. Because it is made in eggs, the vaccine contains 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 receive the vaccine. For this reason, people who are allergic to eggs should not receive the influenza vaccine. However, if people are allergic to eggs and are at high risk of severe influenza infection, they should receive the vaccine under a protocol administered by a physician that minimizes the risk of an allergic reaction.

Q. Does the influenza vaccine work? A. Yes. The influenza vaccine will prevent about 70-90 of every 100 people who receive it from developing moderate-to-severe influenza infection.

Q. When should you get the influenza vaccine? A. The influenza vaccine is given in October and November, just before the influenza season starts. However, the vaccine can be given throughout the influenza season, as late as March.

Q. Who should get the influenza vaccine? A. The inactivated influenza vaccine is recommended for people at highest risk for severe complications caused by influenza virus. Those at highest risk include: people with asthma; people with chronic diseases of the lungs, heart or kidneys; people older than 50; pregnant women; and children between 6 months and 5 years of age. Children less than 9 years of age who have never received an influenza vaccine require two doses. However, all people, no matter how healthy, are at some risk of developing severe and even fatal influenza infections. The FluMist vaccine is currently recommended for healthy people between 5 and 49 years of age and has the advantage of inducing an excellent immune response without requiring a shot.

Q. Should healthy children get the influenza vaccine? A. Yes. There are two reasons that all healthy children 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 that 65 are most likely to catch influenza virus from young children; therefore, immunizing children can also prevent deaths in the elderly.