Flu Myths and Facts

Armen Hareyan's picture

Influenza: Don't Take It Lightly

Influenza, or the flu, causes 20,000 deaths in the US every year. As Americans worry about many infections that are more potential than probable, the common flu may not be getting the concern it deserves.

Flu season in the United States is from November to April. During this period, people are most susceptible to contracting influenza, a virus that infects the respiratory tract. The flu features fever (100 to 103 degrees or more in adults, higher in children), chills, cough, sore throat, runny or stuffy nose, headache, muscle aches, and fatigue. Intestinal symptoms such as nausea, vomiting and diarrhea can sometimes occur, especially among children, but this is rare. In spite of these occasional symptoms, there is no such thing as "stomach flu".

For most people who get it, the flu typically lasts from one to two weeks. However, some people can develop very serious, life-threatening complications such as pneumonia, which accounts for the numerable annual deaths caused by this virus.

Influenza viruses are continuously present, and constantly mutating and evolving into new strains. Scientists believe, for example, that the origin of at least one type of influenza active today, can be dated back to the 1890s. There are currently three strains of influenza virus circulating throughout the world. One of those has caused more than 400,000 deaths in the US alone since it was first identified in 1968.

Research scientists keep track of the various influenza viruses and how they are changing. They do so in order to develop annual vaccines that will address the most current characteristics of each strain of the virus. The Centers for Disease Control and Prevention (CDC), offer predictions about the severity of the three strain's mutations and issue advisories within the medical community about who is most at risk and should be vaccinated.

The elderly and people with chronic illnesses are always advised to receive vaccinations against the flu annually. These groups have always been the most vulnerable to developing serious complications. Beginning in 2000, the CDC began advising that everyone 50 and over should receive a flu shot annually. It is estimated that from 24% to 32% of people between the ages of 50 and 64, have at least one risk factor that makes them susceptible to developing serious complications if they get the flu.

Flu Shots

The flu vaccine available now has been developed to provide immunity against the types of flu considered most likely to occur this season. Flu shots are not 100% reliable; not everyone will be protected. However, success rates are significant enough to warrant receiving the vaccine. Influenza has become so common; laypeople tend to refer to many illnesses as being the flu. A flu shot will not necessarily protect against other illnesses with symptoms that resemble the flu.

Overall, side effects from the flu vaccine are minimal. The most common are soreness at the site of the injection, or minor aches and fever. If any side effects present themselves, they would usually appear 6 to 12 hours after the injection, and last from 1 to 2 days maximum.


The risk of serious side effects to flu vaccine is estimated to occur with a ratio of 1 to 2 cases in one million people vaccinated. These are allergic reactions and Guillain-Barre Syndrome.

Check with a doctor before getting a flu shot if:

  • You have an allergy to eggs (The vaccine is grown in hen's eggs).

  • You have ever been paralyzed with Guillain-Barre Syndrome

  • You are pregnant or might be pregnant

  • You are ill and have a fever

This material is intended to provide general educational information and to help users arrange more easily for health care services. This site is not an attempt to practice medicine or provide specific medical advice and should not be used to make a diagnosis or to replace or overrule a qualified health care provider's judgment. Nor should users rely upon this information if they need emergency medical treatment. We strongly encourage users to consult with a qualified health care professional for answers to personal questions.


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