August 25, 2011
I have an egg allergy. Can I get the flu shot?
Getting the flu shot is very important in those who suffer from asthma, COPD and other chronic illnesses. However some do not get the flu vaccine thinking they may be allergic to it. This misconception has deprived many of the flu shot putting them at risk of potentially life-threatening complications from the flu. Patients, and even some physicians, think that being allergic to eggs or feathers are reasons not to get the flu shot. The CDC has recently released recommendations on what to do when deciding whether to give the flu shot to someone with an egg allergy.
Having an egg allergy does not mean you cannot get the flu shot. The reason many think that a flu shot will cause an allergic reaction in someone with egg allergies is the flu vaccine is made by inoculating it in chicken eggs. The amount of ovalbumin, the egg protein, in the flu vaccine is very little. It is present in micrograms. A typical 0.5 ml flu shot would contain about 0.7 mcg of egg protein. A microgram is 1/1,000 of a 1 mg. or 1/1,000,000 of a gram.
Several published reports have documented the flu shot being given to those with egg allergies without developing an allergic reaction. Some studies have even taken certain precautions before giving the flu shot to someone with an egg allergy -prick skin testing with the influenza vaccine, or giving split doses (10% of initial vaccine dose followed by the remaining 90% of the dose if no reaction occurs 30 minutes after the initial dose). Prick skin testing had no predictive value, and split dosing was generally well tolerated without serious reactions. In one study, 3.5% (6/171) of participants developed systemic reactions (wheezing, eczema exacerbation, and hives on face/chest).
In general, patients with an egg allergy with mild symptoms such as hives can safely be given the flu shot. However for more serious or severe allergic reactions you would need to see your physician or allergist to determine if you can receive the flu shot.
I had an allergic reaction to the flu shot. Am I allergic to eggs?
It is important to distinguish between a flu vaccine allergy and an egg allergy. The flu vaccine has various components other than egg, and generalized allergic reactions to these may occur although extremely rare. These reactions can occur in those without an egg allergy. On the other hand, most people with egg allergies do not develop allergic reactions to the flu shot. An allergic reaction to the flu vaccine does not necessarily mean that one has an egg allergy.
How do I find out if I can get the flu shot if I have an egg allergy?
If you have an egg allergy and are unsure whether you can get the flu shot, it would be wise to see your allergist. An ABAI board certified allergists can determine if the type of egg allergic reaction you had was serious and life-threatening. Also, an allergist can do allergy prick skin testing, split dosing vaccines or doing incremental drug challenges if deemed necessary, and are well trained in treating generalized, anaphylactic reactions. You can also read the CDC’s Flu vaccination recommendations for persons with egg allergy. See Figure
Manuel S. Villareal, M.D., FAAAAI, FACAAI is a Board Certified Allergist/Immunologist practicing in the Northern Kentucky/Cincinnati area.