Can I take a flu vaccine if I have an egg allergy?


A: Yes, you can!

TL;DR: Even for people who have severe egg allergies, flu vaccines are safe and effective. The amount of egg protein is so tiny that it is very unlikely to cause an allergic reaction. There are also 2 available flu vaccines that contain no egg protein at all.

Egg allergy occurs in 1-2% of all children and 0.2% of adults, which makes it one of the more common food allergies.. People with a history of very serious reactions to eggs should take their vaccine at a health care providers office who can help in the very rare case of a reaction occurring.

You may be asking – wait, what does a vaccine have to do with eggs? Viruses need to be inside of a cell to make copies of themselves. Scientists take advantage of thisby using chicken eggs as the host for viral replication for the flu virus. Once there are many copies of the virus, it is purified and broken down into small pieces before being used in the vaccine we receive as our flu shot.

Nerd Alert: a flu vaccine made in this way CANNOT cause a flu infection – the final vaccine does not contain the whole influenza virus. It contains only small chunks of the virus (called inactivated virus) that cause an immune response. For our super Nerds who are wondering, the nasal spray flu vaccine starts the same way, but instead of the virus being broken down, it is weakened (attenuated) so the virus can only multiply in cool temperatures. The virus cannot multiply in places where the temperature is warmer, such as the lungs, so it also does not cause a flu infection but still stimulates an immune response.

Back to eggs and flu vaccines: because the process of making the vaccine starts inside a chicken egg, the final vaccine does contain egg protein. However, the amount of egg protein is so tiny that it is very unlikely to cause an allergic reaction. Its hard to measure exactly how much, but a study reported by the CDC from prior flu seasons measured a max of 1 繕g/0.5 mL dose for flu shots and 0.24 繕g/0.2 mL dose for the nasal spray vaccine. Thats 繕g which is short for microgram, Nerdy Readers – thats less than one millionth of a gram!!

This is why since the 2018-2019 flu season, the CDC has recommended that people with egg allergies may safely take any available flu vaccination. If the egg allergy reaction is a rash or hives, you can take the vaccine without any additional precaution. If the prior egg allergy reaction was more serious, like wheezing, low blood pressure, vomiting or any combo of symptoms that needed an Epipen to treat, the person should receive their vaccine at a health care providers office. In the rare event of a reaction, your health care providers team can help treat the symptoms.

Serious reactions to the flu vaccine such as anaphylaxis do occur but thankfully they are very rare. If you have had anaphylaxis or another very serious reaction to a flu vaccine itself in the past, you should not have another flu vaccine in the future, whether or not you have an allergy to eggs.

If you have egg allergies and are still worried, there are 2 flu vaccines available this season which contain no egg protein at all due to a difference in the vaccine manufacturing:

Flublok Quadrivalent
Flucelvax Quadrivalent

These can be located with the help of your healthcare provider.

If you havent yet taken your flu vaccine this season, NOW is the PERFECT time to get one! We are already beginning to see an increasing number of infections with flu -protect yourself now!

Stay safe. Stay well. Get vaccinated.

Those Nerdy Girls


CDC: Flu Vaccine and People with Egg Allergies

CDC Seasonal Flu Vaccines

Those Nerdy Girls: When is the best time to get my flu vaccine?

Those Nerdy Girls: Busting Flu Shot Myths

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