Each year, approximately 3 to 5 million people throughout the world develop severe symptoms of the influenza, or flu, virus, according to the World Health Organization. People who develop the flu can experience fever, muscle aches, fatigue, headache, nasal congestion or sore throat. Vaccination with the flu shot helps prevent the development of this infection in treated patients. Before receiving this immunization, people should be aware of the potential dangers of the flu shot.
Guillain-Barre Syndrome
The development of Guillain-Barre syndrome, though extremely rare, is a potential danger of the flu shot. Approximately one in 1 million people vaccinated with the flu shot develop Guillain-Barre syndrome, according to the Centers for Disease Control and Prevention. This syndrome, which is also called GBS, is a progressive nerve disorder that causes severe muscle weakness or paralysis. Affected people can also experience fever, numbness or tingling throughout the body due to nerve damage.
People who develop GBS are in danger of experiencing temporary or permanent difficulties walking or moving about normally. Treatment with the flu shot is typically not recommended for people who have a family history of GBS, as this may increase a person's risk of developing this nerve disorder following vaccination.
Allergic Reaction
A severe allergic reaction called anaphylaxis is a potential danger of treatment with the flu shot. People who are allergic to eggs are at the highest risk of developing an allergic reaction following flu vaccination, as this medication can contain egg products. Allergic reaction symptoms can include throat or facial swelling, itchy skin or hives, dizziness, headache, breathing difficulties or heart rate changes. Without prompt medical intervention, allergic reaction symptoms can be fatal. People with a known allergy to eggs should consult a doctor before being immunized with the flu shot, Discovery Health advises.
Side Effects
People who receive the flu shot are in danger of experiencing side effects of this treatment. The most common side effect of the flu shot is an injection site reaction, which can cause inflammation, tenderness or redness of the skin, the CDC reports. Additional side effects may involve a low-grade fever, muscle aches, headache or chills. If these side effects do not resolve within one to two days following flu shot administration, affected people should contact a doctor.
