Both __ and __ immunity can be induced artificially. Active immunity can develop from the introduction of antigens into the bdoy through __, often called __.
- Today, many sources of antigen are used to make vaccines, including inactivated bacterial toxins, killed microbes, parts of microbes, weakened microbes that generally do not cause illness, and even genes encoding microbial proteins. Because all of these agents induce a primary immune respoonse and immunological memory, an encounter with the pathogen from which the vaccine was derived triggers a rapid and strong secondary response.
- active and passive