Active and passive immunity are two different mechanisms by which the immune system provides protection against infectious diseases. Here are five key differences between active and passive immunity:
Source of Protection:
Active Immunity: Active immunity is acquired when the body’s immune system produces its own immune response to pathogens, typically following exposure to an infectious agent or through vaccination. It involves the activation of B cells and T cells, leading to the production of antibodies and memory cells.
Passive Immunity: Passive immunity, on the other hand, is obtained by receiving pre-formed antibodies or immune cells from an external source. The immune protection is immediate but temporary, as the individual’s immune system is not actively involved in producing the antibodies.
Duration of Protection:
Active Immunity: Active immunity often provides long-lasting protection, sometimes for a lifetime. Memory cells generated during the immune response “remember” the pathogens, enabling a faster and more effective response upon subsequent exposure.
Passive Immunity: Passive immunity is temporary, lasting only as long as the transferred antibodies or immune cells remain active in the recipient’s body. The protection diminishes over time as these components are naturally degraded.
Time to Develop Immunity:
Active Immunity: The development of active immunity takes time because it involves the activation and proliferation of immune cells. The body’s response may take days to weeks to reach its full strength.
Passive Immunity: Passive immunity provides immediate protection since pre-formed antibodies or immune cells are directly introduced into the body.
Nature of Immune Response:
Active Immunity: Active immunity results in an individual’s own immune system generating a response, including the production of antibodies and the development of immunological memory.
Passive Immunity: Passive immunity does not stimulate the individual’s immune system to produce an immune response. It involves the transfer of ready-made antibodies or immune cells.
Types of Transfer:
Active Immunity: Active immunity is acquired naturally through infection or artificially through vaccination. In vaccination, a person is exposed to a weakened or inactivated form of the pathogen, stimulating an immune response without causing the disease.
Passive Immunity: Passive immunity can be acquired naturally through the transfer of antibodies from a mother to her baby during pregnancy or breastfeeding. It can also be acquired artificially through the administration of immune globulins or antibodies obtained from donors or animal sources.
In summary, active immunity involves the body’s own immune response and provides long-lasting protection, while passive immunity involves the transfer of pre-formed antibodies or immune cells and provides immediate but temporary protection.