There are four types of influenza viruses: A, B, C and D. Human influenza A and B viruses cause seasonal Influenza almost every year in the United States. Influenza type C infections generally cause a mild respiratory illness and are not thought to cause epidemics. Influenza D viruses primarily affect cattle and are not known to infect or cause illness in people. The Influenza A viruses has 18 different hemagglutinin subtypes and 11 different neuraminidase subtypes. Influenza B viruses are not divided into subtypes, but can be further broken down into lineages and strains. Currently circulating influenza B viruses belong to one of two lineages: B/Yamagata and B/Victoria.


1. Fever, Headache, Runny nose, Sneezing, Chills, Cough, Body or muscle aches, Sore throat.


1. Flu is caused by influenza viruses, and is spread mainly by coughing, sneezing, and close contact. 


1. If you have any severe, life-threatening allergies. If you ever had a life-threatening allergic reaction after a dose of flu vaccine, or have a severe allergy to any part of this vaccine, you may be advised not to get vaccinated. Most, but not all, types of flu vaccine contain a small amount of egg protein.

2. If you ever had Guillain-Barré Syndrome (also called GBS). Some people with a history of GBS should not get this vaccine. This should be discussed with your doctor.

3. If you are not feeling well. It is usually okay to get flu vaccine when you have a mild illness, but you might be asked to come back when you feel better.

4. CDC - 

Children younger than 6 months are too young to get a flu shot.

People with severe, life-threatening allergies to flu vaccine or any ingredient in the vaccine. This might include gelatin, antibiotics, or other ingredients. See Special Considerations Regarding Egg Allergy for more information about egg allergies and flu vaccine.


1. Severe allergic reaction (e.g., anaphylaxis) to any component of the vaccine including egg protein, or to a previous dose of any influenza vaccine

2. Hypersensitivity to Eggs, Antibiotics, Sensitivity to other components, Previous life-threatening reactions to a Flu Vaccine


1. Flu vaccine cannot prevent: 

* Flu that is caused by a virus not covered by the vaccine, or 

* Illnesses that look like flu but are not.

2. If Guillain-Barré Syndrome (GBS) has occurred within six weeks of previous influenza vaccination, the decision to give FLUAD should be based on careful consideration of the potential benefits and risks.

3. Appropriate medical treatment and supervision must be available to manage possible anaphylactic reactions following administration of the vaccine.