Family Practitioner Questions Allergies

Eggs and flu shots

Why am I asked if I am allergic to eggs when I get a flu shot?

9 Answers

Flu shot can contain egg protein depending on the flu shot formulation.
The vaccine has protein extract from eggs.
People with allergies to eggs may have an allergy to components in the vaccine.

Richard Aballay

Nasal spray.
When flu vaccines are made, part of the process involves replicating the flu virus inside a chicken egg! The virus is then broken down to get the proteins that are used to make the vaccine. In theory, someone with a severe egg allergy might have a reaction to the shot, though there is no egg in the shot itself.
A protein from eggs is used as a preservative. Most people think that if they’re allergic to eggs at all, then they can’t have the influenza vaccination; however, this isn’t the case. If you can eat baked goods with eggs baked in them, then you can have the flu shot.
The majority of flu vaccines are cultured on fluid from chicken embryos and therefore have a small amount of egg protein in them. This poses a theoretical risk of inducing an allergic reaction to thos who have egg allergies. However over the years, the amount of egg protein in the flu vaccines have decreased significantly and no serious reactions have been reported even in patients with severe egg allergies. Egg allergies are no longer considered contraindications to receiving the flu vaccines. It is recommended that all patients ≥6 months of age with egg allergy, including those with a history of anaphylaxis, receive annual immunization with an influenza vaccine according to the indications for all other patients without egg allergy.
Some flu vaccines are made using eggs and may have a small amount of egg proteins in them. If you are truly allergic to eggs, you may have an allergic reaction to the flu vaccine. If you are truly allergic (get a rash, shortness of breath, trouble breathing, etc.) and are over 18 years old, you can receive the flu vaccine called Flublok. This vaccine is made chemically and is free of egg protein. It is also free of formaldehyde, antibiotics, gluten, gelatin, latex, thimerosal, and other preservatives.
Flu shots are manufactured using egg based technology. There was a concern that if you are allergic to eggs you may have an allergic reaction to the vaccine. However the amount of egg protein in the vaccine is very tiny, so unless you have a history of anaphylactic reaction to eggs you are generally considered a safe applicant for the flu vaccine. Even with anaphylaxis reaction it may be ok for you to get the vaccine but you need to be monitored in an appropriate setting capable of handling an anaphylactic reaction. Make sure you discuss your concerns with your doctor.