If you or your child have been diagnosed with an egg allergy, you know first-hand how many places this sneaky allergen can hide. But did you know that some vaccines also contain egg proteins, including many flu shots?
In this post, we’ll discuss why for most people with egg allergies, vaccines like the flu shot should pose no problem.
What is an Egg Allergy?
Certain types of reactions to egg or egg-containing products can indicate an egg allergy. Egg allergy is diagnosed with a consistent medical history of immediate symptoms after eating eggs or egg-containing foods, plus skin and/or blood testing for immunoglobulin E focused on egg proteins. Some people with egg allergies can tolerate eggs cooked in certain ways but not others (i.e. they may be able to eat a cake baked with an egg but cannot eat a scrambled egg).
Egg allergies affect about 1.3% of all children in the U.S. and just 0.2% of all adults.
Egg Protein in the Flu Vaccine
Most flu vaccines today contain a small amount of egg protein called ovalbumin due to being produced using an egg-based manufacturing process. Not all manufacturers tell how much ovalbumin they put in their vaccines. However, from those that have, we estimate that there is a very small amount, less than or equal to 1 µg, of ovalbumin in each flu shot dose. There is even less egg protein in the flu nasal spray vaccine. Furthermore, there are now manufacturers that produce flu vaccines without using eggs at all in the manufacturing process.
Flu Vaccines Without Egg Proteins
For the 2021-2022 flu season, there are two vaccines licensed for use in the U.S. that are considered egg-free:
- Flublok Quadrivalent (licensed for use in adults 18 years and older)
- Flucelvax Quadrivalent (licensed for use in people 6 months and older)
Flu Shot Recommendations for Egg-Allergic People
The severity of your egg allergy will determine how you should proceed with the flu shot. If you are still concerned, opt for one of the two flu shots that do not contain eggs (see above).
Mild or Moderate Egg Allergy:
If you can eat lightly cooked eggs without reacting, or if you only have a history of hives after egg exposure, you can receive any approved flu shot in the U.S. that is appropriate for your age and health status.
Severe Egg Allergy:
If exposure to eggs or egg-containing products has ever caused:
- Respiratory distress
- Recurrent emesis
- Use of epinephrine or another emergency medical intervention
…it is recommended by some health officials that you only receive an approved U.S. flu shot in a medical setting with personnel trained in anaphylaxis. This includes allergist clinics like ours. You could also receive an egg-free flu vaccine.
Who Should Not Get the Flu Shot?
Anyone who has had a severe allergic reaction to a flu shot in the past, regardless of the cause, should not get a flu shot again.
Allergic Reactions to the Flu Vaccine
There have been infrequent reports of anaphylaxis, a severe life-threatening reaction that involves multiple organ systems and can progress rapidly, in egg-allergic people who have received a dose of flu vaccine. Various components of the flu vaccines may cause allergic reactions, so it’s hard to know if all cases of reported anaphylaxis in egg-allergic people are due to egg protein. In a Vaccine Safety Datalink study of more than 25.1 million doses of vaccines of various types given to children and adults over 3 years, only 33 people had anaphylaxis. Most cases of anaphylaxis related to vaccine administration are reported to the Vaccine Adverse Event Reporting System (VAERS).
Allergic Reaction Timeline After the Flu Vaccine
Onset of an allergic reaction after being administered a flu shot can be immediate or delayed. The same Vaccine Safety Datalink study mentioned above noted that the onset of most of the 33 cases of anaphylaxis was more than 30 minutes after the shot was given.
Allergy Treatment in Tampa Bay
No matter what type of allergy you are dealing with, the team at Allergy, Asthma, and Immunology Associates of Tampa Bay has the knowledge and tools to identify your triggers and develop a treatment plan that works for you. Call us at (813) 971-9743 to schedule a complete allergy workup before receiving any vaccines if you have concerns about safety. We can review your health history and help guide you to making safe, well-informed choices about your health.