Differentiate between active and passive immunity
Active immunity is a type of immunity that the body develops in response to an infection or vaccination. It involves the activation of the immune system, which produces antibodies and memory cells to fight off future infections. On the other hand, passive immunity is a temporary form of immunity that is acquired from external sources, such as through the transfer of antibodies from a mother to her child or through the administration of antibodies from another individual.
Active immunity is characterized by the body’s own immune response. When a person is exposed to a pathogen, such as a virus or bacteria, the immune system recognizes it as foreign and mounts an attack. This response involves the production of antibodies, which are proteins that specifically target and neutralize the pathogen. Additionally, memory cells are generated during the immune response, which provide long-term protection against future infections by the same pathogen.
In contrast, passive immunity is acquired from external sources and does not involve the body’s own immune response. When a person receives passive immunity, they are given pre-formed antibodies that can immediately neutralize the pathogen. This can be achieved through the transfer of antibodies from a mother to her child during pregnancy, breastfeeding, or through the administration of antibodies from another individual, such as through a blood transfusion or injection of immune globulin.
One key difference between active and passive immunity is the duration of protection. Active immunity provides long-lasting protection because the body’s immune system retains memory cells that can quickly respond to future infections. This is why vaccines are effective in preventing diseases, as they stimulate the immune system to produce memory cells. In contrast, passive immunity is temporary and wears off over time. The antibodies acquired through passive immunity are eventually broken down and eliminated from the body, leaving the individual vulnerable to reinfection.
Another important distinction is the ability to induce memory. Active immunity generates memory cells, which provide long-term protection against specific pathogens. This is why vaccines are effective in preventing diseases even after the initial exposure has passed. In contrast, passive immunity does not induce memory cells, as the antibodies are provided externally. Therefore, individuals who receive passive immunity are not protected against future infections by the same pathogen.
In summary, active immunity involves the body’s own immune response, produces memory cells, and provides long-lasting protection. Passive immunity, on the other hand, is acquired from external sources, does not induce memory cells, and provides temporary protection. Understanding the differences between active and passive immunity is crucial in developing effective strategies for disease prevention and treatment.
