Skin Test Vaccine

**Semantic type:** Pharmacologic Substance

**Definition:** A preparation of an antigenic component of an infectious agent that is administered to a patient in order to determine whether previous exposure to the agent has occurred, and/or to assess the integrity of the patient's cellular immune system. Depending on the clinical situation, the appearance of a delayed (cellular) hypersensitivity response, which manifests as an area of induration and erythema at the injection site, i.e. a positive test result, may indicate previous exposure to a particular infectious agent. (NCI04)