How Do Antibodies Work?

When a pathogen (virus, bacterium, or other invader) enters the body, its surface molecules (antigens) are detected by B lymphocytes in the immune system. Each B cell produces antibodies with a unique binding site that fits a specific antigen shape — like a lock and key. Once a B cell encounters its matching antigen, it multiplies rapidly and secretes millions of antibodies into the bloodstream. These antibodies work in several ways: they can neutralise the pathogen directly, clump pathogens together for easier clearance, or tag them for destruction by other immune cells (opsonisation). Some B cells become memory cells, providing long-lasting immunity for future encounters.