Flu Shot Side Effects

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Many people worry about side effects from the flu shot, but serious complications are rare. Some people believe that they can actually get the flu from receiving the shot, but this is not the case. For the majority of people, the risks of developing the flu are far greater than any risks associated with the vaccine.

Most side effects and reactions to the flu shot are mild. Most commonly, people experience a soreness, redness, or mild swelling at the site where the shot was given. These effects generally do not last for more than 2 days. In rare cases, people may develop other mild reactions to the flu vaccine like fever and aches, which may mistakenly lead them to believe that they developed the flu as a result of the vaccine. These symptoms also go away after about 1 to 2 days. Because the flu shot contains inactivated, or killed, virus particles, there is no possibility of contracting the infection from the flu shot.

Allergic reactions to the flu shot are very rare. Symptoms of an allergic reaction can include:

People who are allergic to eggs are more likely to have an allergic reaction to the flu shot because the viruses used to make the vaccines are grown in chicken eggs. Those who are allergic to eggs or who have had a serious reaction to a previous flu shot should always discuss the situation with a doctor prior to receiving a flu shot.

Another extremely rare potential complication of a flu shot is Guillain-Barré syndrome. This is a disease characterized by nerve damage, weakness, and fever that developed in some cases in association with the swine flu vaccine in 1976. Only one research study has shown any association of Guillain-Barré syndrome with subsequent flu shots developed since 1976. That study showed that only one person out of 1 million vaccinated persons may be at risk of Guillain-Barré syndrome associated with the vaccine.

It's recommended that everyone over 6 months of age receive the flu vaccine. The risks of complications from the flu are more serious than any potential risks of the flu shot. Only those people allergic to eggs and those who have had a previous severe reaction to the shot (an allergic reaction or Guillain-Barré syndrome) should consult a doctor before receiving the vaccine.

Flu Shot Side Effects Resources

Read patient comments on Flu Vaccination - Side Effects

Doctor written main article on Flu Vaccination

Medically reviewed by Robert Cox, MD; American Board of Internal Medicine with subspecialty in Infectious Disease


Medically Reviewed by a Doctor on 7/13/2016

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