How do antibodies work?

Foreign cells that enter the body have antigens on the outside of them which will be complementary to a specific antibody. The antibody can bind to the antigen, forming an antigen-antibody complex, and this causes agglutination of the pathogens so they can be destroyed more easily by phagocytosis, carried out by macrophages. The pathogen is engulfed and held within a phagocytic vacuole, which fuses with a lysosome that contains lysozymes. These lysozymes are enzymes which can break down the pathogen and allow the antigens to be presented by the phagocyte, activating B cells and T cells. Antibodies also neutralise toxins released by pathogens using antitoxins.

More antibodies are produced when B cells are activated by the antigens being presented by these antigen-presenting cells. One B cell divides into plasma cells, which can all produce many monoclonal antibodies against the specific antigen.