An antibody and antigen interaction defines immune specificity. The antibody and antigen bond occurs through complementary regions, triggering immune defense or detection responses. Understanding this binding mechanism is crucial in vaccine design, diagnostics, and immunoassay development, shaping the foundation of adaptive immunity research and biomedical innovation. https://www.betalifesci.com/blogs/news/antibody-vs-antigen-vs-epitope-vs-hapten-vs-immunogen