What is the difference between active and passive immunity? Active immunity is when you are exposed to a disease or infection and your body produces antibodies to fight it. Passive immunity is when you receive antibodies from another person or animal. Antibodies can be given through a vaccine, injection, or infusion. Passive immunity lasts for a shorter time than active immunity.
What is Active Immunity?
Active immunity is the process by which an individual’s immune system produces antibodies in response to and becomes primed to recognize a pathogen. The individual will then be able to rapidly mount an immune response upon re-exposure to the pathogen. Active immunity usually develops after a person is vaccinated or infected with a pathogen. It can also occur naturally when a person is exposed to a pathogen and their immune system responds by producing antibodies.
Active immunity generally lasts for a longer period of time than passive immunity, which is when antibodies are transferred from one individual to another. Active immunity can be life-long, while passive immunity generally only lasts for a few weeks or months. Active immunity is typically more effective than passive immunity at protecting against disease.
What is Passive Immunity?
- Passive immunity is the transfer of immunity, usually from one individual to another. Passive immunity can be conveyed via antibodies in breast milk, the transplacental crossing of maternal antibodies, or the injection of purified antibodies. Passive immunity provides protection against infection for a short period of time (usually only a few months). This type of immunity does not require immunization and it cannot be passed from one individual to another.
- Passive immunity is conferred by the transfer of antibodies. The half-life of maternal antibodies in neonates is about 27 days. At birth, a neonate has high levels of maternal IgG that are transferred across the placenta. This provides passive immunity against certain infectious diseases such as tetanus, polio, and measles.
- Passive immunity can also be conferred via injection of immune globulin (IG) or serum-containing antibodies. IG is indicated for prophylaxis or treatment of certain infections such as hepatitis A, varicella-zoster virus (VZV), and rabies. Passive immunity is temporary and lasts for only a few months. Active immunity is required for long-term protection against infection. Active immunity can be acquired by vaccination or natural infection.
Difference between Active and Passive Immunity
Active immunity is immunity that is induced by the presence of an antigen. Active immunity can be acquired through natural infection, vaccination, or artificial immune stimulation. Passive immunity, on the other hand, is immunity that is conferred by the transfer of antibodies. Passive immunity can be acquired through the placental transfer of antibodies from mother to child, the transfer of antibodies in breast milk, or the administration of artificially derived antibodies (known as gamma globulin).
Active immunity is typically longer lasting than passive immunity, but both forms of immunity are important in protecting against disease. Active immunity helps to build up a person’s immune system so that they can better fight off infection, while passive immunity provides a short-term boost that can help to protect against disease until active immunity can be established.
Conclusion
Immunity is a critical aspect of human health and can be classified in two ways: active immunity and passive immunity. Active immunity is produced when the body mounts an immune response after being exposed to a pathogen. Passive immunity, on the other hand, occurs when antibodies are transferred from one person (or animal) to another. While both types of immunity are important, understanding the difference between active and passive immunity is key for making informed decisions about vaccinations and other treatments.
