Answer: well I know it sounds a bit weird but it’s made with chicken eggs
Explanation: Because Proteins from chicken eggs help viruses to grow before they go into the vaccine. Influenza viruses used in vaccines are usually grown inside fertilized chicken eggs, where the virus makes copies of itself. After that, the viruses are separated from the egg and placed in the vaccine; this means that the finished vaccine may contain small amounts of egg proteins.The CDC say that the flu shot is typically safe for people with egg allergies, but those who have an egg allergy must mention it to the doctor before receiving the shot. A person with a severe egg allergy may require monitoring by a doctor following the injection.