Egg-containing vaccines include influenza, rabies, and yellow fever. Influenza vaccines are grown in chick embryo fibroblast cultures, leading to concern that residual egg protein (ovalbumin) could provoke an allergic reaction in patients with egg allergies. However, studies to date have suggested that the risk of a reaction is very low.
10 Also, the newly available recombinant hemaglutinin influenza vaccine, trivalent (RIV3), does not contain egg protein. According to ACIP recommendations,
11 a person who can eat lightly cooked eggs without reaction may receive the influenza vaccine using the standard protocol. A person who experiences only hives after eating eggs or egg-containing food should receive either RIV3 (if aged 18 to 49 years) or inactivated influenza vaccine.
2 A person who experiences severe symptoms after eating egg or egg-containing foods (eg, cardiovascular changes, respiratory distress, gastrointestinal symptoms, reaction requiring epinephrine or emergency medical attention) should receive RIV3 if aged 18 to 49 years or be referred to an allergist for further evaluation and vaccine administration.
Numerous studies have demonstrated that the influenza vaccine can be safely administered in 1 full dose, even to patients with a history of anaphylaxis to egg ingestion, as long as appropriate precautions are taken. The American Academy of Asthma, Allergy, and Immunology 2012 practice parameter update on adverse reaction to vaccines
6 recommends that patients with egg allergy receive influenza vaccinations. The benefits of vaccinating these patients outweigh the risks. Inactivated influenza vaccine should be used.
6 Live attenuated influenza vaccine (nasal flu vaccine), which also contains egg allergen, has not been studied in patients allergic to eggs; therefore, it is currently not recommended for use in this population. The ACIP guidelines
12 for yellow fever vaccine recommend that that if a patient with egg sensitivity requires the yellow fever vaccine for travel purposes, a skin test may be done to the vaccine itself. If positive, or if the egg allergy is “severe,” desensitization may be performed. To our knowledge, there are no studies or formal guidelines for the administration of the rabies vaccine in egg-allergic patients. In all of these cases, referral to an allergist would be warranted for testing and desensitization if necessary.