July 15, 2010
by Catherine Frompovich
What do peanuts and vaccines have in common? Well, you’re probably thinking that some people have allergic reactions to both, and you are correct. Peanuts cause the most common severe food allergy reactions. Vaccines, on the other hand, that are grown on chicken eggs (MMR and influenza vaccines in particular) cause allergic reactions for which pharmaceutical and vaccine makers willingly provide cautionary notices on vaccine package inserts. It’s important to note that technically there can be two responses: a reaction, e.g., immediate allergic response (anaphylaxis), and a side effect, e.g., fever, rash, or localized swelling later on.