There is more than one. Allergy [Strange Malady] is one of them. If we had no curative serums and if there were no such thing as a hypodermic syringe with which to introduce the material under the skin, there would be no serum disease. Subsequent exposure to the protein can result in allergic reactions or anaphylaxis. It is well recognized that many currently approved vaccines have enough allergen to cause anaphylaxis. Therefore, they contain more than enough allergen to cause sensitization.