Antibody-mediated immunity is another name for humoral immunity. This physiological process, which is a part of both the innate and adaptive immune systems, protects the body from infections and foreign chemicals in extracellular fluids.

It entails a two-stage, humoral immune response: primary and secondary. The primary phase is initiated by the body's initial interaction with an antigen (surface protein present on the membranes of pathogens); the secondary phase reflects the immune system's response to repeated contact with the same antigen.

Several immune cell types offer humoral immunity, which occurs in distinct stages. Older vaccines activate the humoral immune response by delivering weakened or deactivated pathogens; more recent vaccine innovations use templates or mRNA sequences to activate the humoral immune response. As a result of the COVID-19 pandemic, several more recent vaccines are in the news.

The majority of infections proliferate in extracellular spaces and move via this fluid milieu. Some use the extracellular space to move between cells and move from one cell to the next.

Humoral immune responses encompass the majority of immunological responses mediated by antibodies found in plasma, lymph, and tissue fluids. It protects against extracellular pathogens and foreign macromolecules. This immunity is transferred to the recipient by the transmission of antibodies. The activation and effector phases of the humoral responses of the immune system.

An APC, such as a macrophage, ingests the antigen through phagocytosis and degrades it in a lysosome.

On the macrophage, a T-cell receptor identifies processed antigen bound to a class II MHC protein.

Cytokines released by TH cells and IL-1 secreted by macrophages drive TH cells to develop and form a clone of B-cell-interacting cells.

Lymphatic tissue enters an activation phase.

When a TH cell receptor interacts to an antigen—MHC II complex on a B cell, cytokines are released.

These cytokines induce the B-cell to generate clones of B-cells. Now, these B-cells create plasma cells that secrete antibodies.