A patient reports a severe egg allergy. Which immunization is contraindicated?

• A. Hepatitis B vaccine.
• B. Pneumococcal vaccine.
• C. The influenza vaccine (egg-based).
• D. MMR vaccine.

Answer: (C)

When someone has a severe egg allergy, the vaccine that is most likely to cause a reaction is the one produced in eggs. The influenza vaccine is grown in eggs and can contain residual egg protein, so giving it to someone with a severe egg allergy carries a real risk of anaphylaxis. That’s why it’s considered contraindicated in this specific circumstance.

The other vaccines listed aren’t dependent on egg protein. Hepatitis B and pneumococcal vaccines are made using recombinant or other non-egg-based methods, so they don’t pose a problem for egg-allergic individuals. The MMR vaccine is produced in chick embryo cells, but it does not contain egg protein in amounts that would trigger an egg allergy, so it is considered safe for those with severe egg allergy.

So the reason the influenza vaccine is the contraindication here is its egg-based production and potential egg protein content, which can trigger severe allergic reactions in someone with a severe egg allergy.