Specific Acquired Immunity

Body in the long run develops specific immune mechanisms for each species. These mechanisms are not innate but are acquired after exposure to the specific organism. Acquired (adaptive) immunity, therefore, refers to antigen-specific defence mechanisms that take several days to become protective and are designed to react with and remove a specific antigen. This is the immunity one develops throughout Adaptive immunity usually improves upon repeated exposure to a given infection and involves:

• Antigen-presenting cells (APCs) such as macrophages
• The activation and proliferation of antigen-specific B-lymphocytes
• The production of antibody molecules, cytotoxic T-lymphocytes (CTLs) and cytokines