What type of immunity do antibodies primarily mediate?

Antibodies primarily mediate humoral immunity, which is a crucial aspect of the adaptive immune response. Humoral immunity involves the production of antibodies by B lymphocytes (B cells) in response to specific antigens. When these B cells encounter an antigen, they undergo activation, proliferation, and differentiation into plasma cells, which secrete large quantities of antibodies into the bloodstream and lymphatic system.

These antibodies serve several functions: they can neutralize pathogens directly, tag pathogens for destruction by other immune cells, and activate the complement system to enhance the ability to clear infections. This process provides a specific and long-lasting defense against pathogens.

In contrast, other types of immunity highlighted in the question serve different roles. Cell-mediated immunity, which involves T lymphocytes and does not primarily rely on antibodies, focuses on the direct destruction of infected cells or the regulation of immune responses. Passive immunity refers to the transfer of pre-formed antibodies from one individual to another, such as from mother to child, while innate immunity serves as the body’s first line of defense against pathogens and does not involve specific antibodies. Understanding these distinctions helps clarify the vital role humoral immunity plays in overall health and disease resistance.