Definitions

• Pathogen ?

  disease causing micro organism
• Active immunity?

  Immunity provided by the immune response upon detection of a pathogen
• Antibody ?

  protein found in the blood which binds to antigens
• Antigen ?

  marker molecules that can be detected by antibodies
• Helper T cell ?

  type of T cell that stimulated cytotoxic T cells, B cells and phagocytes
• Phagocytosis ?

  The process where phagocytes engulf and destroy material
• Vaccine ?

  Introduction of dead or inactive pathogens to stimulate an immune response and provide long term immunity