Final answer:
When administering a vaccine like the mumps vaccine to an adolescent, epinephrine should be readily available as it is used to treat severe allergic reactions, such as anaphylaxis. The Correct Answer is epinephrine.
Step-by-step explanation:
The medication that should be available when administering an immunization, such as the mumps vaccine, is epinephrine. This drug is crucial in the treatment of anaphylaxis, a severe allergic reaction that can occur in response to allergens, including vaccines. An epinephrine injection can rapidly counteract the effects of anaphylactic shock by constricting blood vessels to increase blood pressure, relaxing smooth muscles in the lungs to improve breathing, modulating heart rate, and reducing swelling that could block airways.
Patients with known severe allergies often carry an EpiPen®, which is a preloaded autoinjector of epinephrine that can be used in emergencies. Therefore, when administering vaccines, it is essential to have epinephrine on hand to manage any potential severe allergic reaction swiftly.