Egg Allergy and Vaccines

There are three vaccines that are manufactured using chicken eggs:  MMR, influenza, and yellow fever vaccine.  If your child has a history of allergic reactions to eggs, you might be concerned about reactions to these vaccines.  But for most children, they are perfectly safe.

Experts are much less concerned about reactions in children with mild allergic reactions to eggs, such as hives or other rashes, vomiting or diarrhea.  Severe wheezing or “anaphylaxis” might be of more concern, but even in these children, reactions are very unusual.

MMR vaccine has been extensively studied.  Serious reactions to MMR vaccine in people known to be severely allergic to eggs are extremely rare; serious reactions in people who are only mildly allergic to eggs are nonexistent.  This is not surprising, because the vaccine is produced using egg fibroblasts (a type of cell found in eggs), not whole chicken eggs.  Children with known allergy to eggs should receive MMR vaccine as usual, although for safety the child should be observed for reactions.

Most flu vaccines are produced using whole eggs.  But there are very few reports of dramatic reactions after flu vaccine is given to children with severe egg allergy.  Most experts recommend that flu vaccine should be given as usual to children with severe egg allergy, with an observation period in the office afterwards.  For children with milder allergy, flu vaccine may be given without special concern.

(For more information, see this CDC website:
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6430a3.htm#Influenza_Vaccination_Persons_History

Yellow Fever vaccine is also produced using chicken eggs.  We do not administer this vaccine.  If you are visiting a 3rd-world country which recommends it and your child is allergic to eggs, you should discuss the risks and benefits with the provider who administers the vaccine.