Influenza Prevention & Protection
What are the risks and side effects of the flu vaccine?Serious side effects from the flu vaccine aren’t common: Soreness, redness, warmth, and a slight swelling at the injection site can occur, although they usually last less than two days.
Muscle pain, headache, slight fever, lymph node swelling, nausea, vomiting, diarrhea, dizziness, or fainting can be a side effect, but should go away within a day or two.
Very rarely, serious side effects have been reported: (1) severe allergic reactions (urticaria, trouble breathing, accelerated heartbeat, changes in behavior, dizziness, etc.); (2) acute disseminated encephalomyelitis (fever, headache, seizures ,etc.); (3) Guillain-Barre syndrome (weakness, paralysis etc.); (4) seizures; (5) liver dysfunction; or (6) asthma attacks.
If you have any of these side effects, call your doctor immediately.
Who shouldn't get a flu shot?・People with severe, life-threatening allergies to flu vaccine or any ingredient in the vaccine.
・People with an obvious fever (37.5°C or higher) or a severely acute illness.
・Other conditions that a doctor considers inappropriate.
Who should consult a doctor beforehand?・People being treated for heart, kidney, liver, blood disease or a developmental disorder.
・People who had a fever within two days of a previous vaccination or an allergic reaction, including rash and urticaria.
・People who have had a seizure in the past.
・People who have been diagnosed with an immunodeficiency in the past or has a family member or relative with an immunodeficiency.
・People with an allergy to eggs or any of the vaccine ingredients.
・People who are not feeling well.
After receiving a flu shot...・An acute adverse reaction can often develop within 30 minutes after the vaccination. Ensure that a doctor can be contacted immediately.
・Keep the vaccination site clean. Bathing is allowed, but avoid rubbing the vaccination site.
・Avoid strenuous physical activity on the day of the vaccination.
・If there’s an abnormal reaction at the vaccination site or a change in your physical condition after the vaccination, contact a doctor immediately.