Cross-reactivity

Cross-reactivity applies to the reaction between two different species as opposed to the self-reactivity. In chemistry it means a reaction between two different molecules. At the same time each of these molecules is able to react with the identical molecule, or as it is usually described, to react with itself. In immunology, the cross-reactivity has a more narrow meaning of the reaction between an antibody and an antigen that differs from the immunogen. It is sometimes also referred to as crossimmunity or cross-protective immunity, although cross-reactivity does not necessarily infer cross-protection. A few examples of cross-reactivity have been confirmed in humans, one of which involves influenza virus-specific CD8+ T cell and hepatitis C virus antigens.