By Patty de Urioste, MD
October, 2005
Updated by Roy Benaroch, MD, May, 2008
The flu is always a topic of interest and concern as fall arrives. The last few years have brought increased awareness because of the shortages of the vaccine and reports of severe complications after infection. I hope that the following answers to frequently asked questions will be helpful to sort out some of the facts from the myths that have become prevalent.
What is the flu?
Many times someone will say they have the “stomach flu” or “the flu”. To tell the truth, most of the time these do not represent infection by the virus that actually causes “the real flu”. The flu–properly called influenza–is a highly contagious respiratory illness and is caused by one of three influenza viruses: A, B, or C. Types A and B can cause severe illness whereas Type C only causes a mild respiratory illness and as such is not considered a dangerous infection. Type B is only found in humans, but Type A can be found in and transmitted between other animals and humans.
Why is it important?
In the US 5 to 20% of the population will contract the flu each year. Over 200,000 people are hospitalized because of complications from influenza and 36,000 will die. People at high risk for complications include young children, older people, and those with certain health conditions.
How do I get the flu?
Influenza is extremely contagious and can be transmitted in respiratory droplets produced by coughing or sneezing, or by touching a surface that has been infected and then touching one’s own nose, mouth or eyes. Most healthy people are able to infect others beginning one day prior to feeling ill and up to seven days after the symptoms start.
How do I know if I have the flu?
Symptoms of the flu include high fever, headache, extreme tiredness, dry cough, sore throat, runny or stuffy nose, muscle aches and GI symptoms (especially in children), such as nausea, vomiting and diarrhea. Complications are not uncommon in the flu. These include bacterial pneumonia, dehydration, sinusitis, ear infections, and worsening of medical conditions such as asthma, diabetes, and heart disease.
Who is at high risk?
Anyone can become infected with the influenza virus and could become very ill, but some groups have an especially high risk of complications. Included are children under 2 years old, people 65 years old and older, those who are in long term care facilities (such as nursing homes) and anyone with a chronic medical condition (such as asthma, heart disease, or diabetes).
How can I keep from getting the flu?
The best way is to get a flu vaccine every year. Other ways to help reduce your risk are to avoid close contact with those who are sick, stay home when you are sick, cover your mouth and nose when sneezing or coughing, avoid touching your eyes, nose and mouth, and wash your hands.
I’ve heard that there is more than one type of flu vaccine. Is this true?
Yes, there are two types of flu vaccine available. One is given by injection and the other is a nasal spray. The flu shot does not contain live virus and is approved for use in people 6 months old or older. The nasal spray is made using live, weakened flu viruses that are only able to reproduce in the nose and throat. These weakened viruses cannot survive in the lungs, and therefore are unable to cause the real flu. This vaccine is approved for use in healthy persons between 2 years old and 49 years old. The use of flu vaccine can reduce your chances of contracting influenza by up to 90%.
Why has there been a shortage of flu vaccine in the last couple of years?
Research has shown that both types A and B of the influenza virus regularly undergo genetic mutations. This means that the flu vaccine must continually be revised. Every year the World Health Organization (which includes the CDC in Atlanta, Georgia) meets to decide on the composition of the new flu vaccine for the next year. These experts take into account any changes in the influenza virus that have been observed in the world during that year. Using this information the exact make-up of the next vaccine is determined.
There are four manufacturers that supply the U.S. with vaccine. Preparation of the vaccine is a complex process that takes several months to complete. If there are any problems during the manufacturing process it could cause millions of doses to be lost. This has happened in the past. Also, if the companies that make the vaccine have a surplus they will not produce as much the next year. Both of these factors contribute to the shortages.
What are the side effects of the vaccine?
Some people get soreness, redness and swelling at the shot site. Low grade fever and body aches are also possible. Any symptoms should only last 1-2 days if they even occur at all.
Who should get vaccinated against the flu?
Anyone in a high risk group needs to be vaccinated. This includes children between 6 months and 18 years old, people 65 years old or older, those with medical problems (such as asthma, heart disease and diabetes), women who are pregnant, and health care workers. This is not a complete listing, so contact your doctor to decide if you are in a high risk group. After the high risk groups have been vaccinated everyone else is encouraged to receive the immunization.
People who should not get the vaccine include those with a severe allergy to chicken eggs, those who have had a severe reaction to the vaccine in the past, and babies under 6 months old.
The vaccine is given October through March, but is best given early in case the flu arrives in the fall.
How do I know if I have the flu and what can I do if I get it?
The flu often causes high fever, headache, extreme tiredness, dry cough, sore throat, runny or stuffy nose, muscle aches and even nausea, vomiting and diarrhea, lasting several days. To be certain, see your doctor as soon as the symptoms occur. A quick lab test can be performed to diagnose the flu and, if it is within the first 48 hours of the illness, a medication can be given to shorten the course of influenza and decrease its severity. Rest, increased fluids, avoiding alcohol, tobacco products and aspirin are important. Also, stay at home to avoid infecting others!
For more information you can look at the web site of the Centers for Disease Control at www.cdc.gov/flu.