Which prefix means "exempt or immunity" in medical terms?

The prefix that signifies "exempt or immunity" in medical terminology is "immun/o." This prefix is derived from the Latin root "immunis," which means "exempt" or "free from." In medical contexts, it is commonly associated with the immune system and its functions, such as in terms like "immunology," the study of the immune system, and "immunization," which refers to the process of making someone immune to a disease.

The other prefixes do not convey the same meaning. For instance, "aut/o" pertains to self or automatic processes, "globin/o" refers to proteins related to blood, and "anti-" denotes against or opposite, often used in terms like "antibiotic." Therefore, "immun/o" is the distinct prefix that aligns with the concept of exemption or immunity within a medical framework.