Which type of immunity is established after exposure to an antigen?

Active immunity is established after exposure to an antigen when the body's immune system responds by producing its own antibodies. This process occurs naturally when an individual is exposed to a pathogen, leading to the development of a specific immune response, which includes the creation of memory cells. These memory cells ensure that if the same pathogen infects the body again in the future, the immune system can recognize and fight it off more effectively.

Active immunity can also be acquired through vaccination, where an individual is exposed to a harmless form of the antigen, stimulating the immune system without causing the disease. This prepares the immune system for a real infection by the same pathogen later on.

Natural immunity generally refers to immunity that occurs through natural processes, such as coming into contact with the disease. While natural immunity is correct in some contexts, it does not specifically highlight the aspect of the immune system actively responding to the antigen itself.

Passive immunity involves receiving antibodies from another source, such as maternal antibodies transferred to an infant, and does not involve the recipient's immune system actively producing its own antibodies.

Cell-mediated immunity is a form of immune response that involves T cells and does not directly relate to the production of antibodies as in the case of active immunity. It plays a role in the recognition and destruction