Active & Passive Immunity

• Making antibodies and developing memory cells for future response to infection is known as active immunity
• There are two ways in which this active immune response happens:

  • The body has become infected with a pathogen and so the lymphocytes go through the process of making antibodies specific to that pathogen
  • Vaccination
• Active immunity is slow acting and provides long-lasting immunity
• Some cells become memory cells that remember the right antibodies to make in case the pathogen comes back
• Active immunity takes time that the infected person may not have
• To shortcut, antibodies can be given directly
• Passive immunity is a fast-acting, short-term defence against a pathogen by antibodies acquired from another individual
• Antibodies pass from mother to infant via breast milk - this is important as it helps the very young to fight off infections until they are older and stronger and their immune system is more responsive

  • The body does not make its own antibodies or memory cells in passive immunity, hence the name