Barrier immunity. Eg: Skin is a physical barrier as well as chemical and biological barrier as it produces antimicrobial proteins; Surface lining of the respiratory system has cilia for preventing pathogens and building up of microorganisms; Stomach release strong acids with low pH and kills microorganisms that we accidentally ingest while eating; tears also is an example of barrier immunity as it protects our eyes from dust and pathogens. Innate immunity. When a microorganism is successful in crossing barrier immunity, innate immunity is activated.
Innate immunity is non-specific and is present before birth. Neutrophils, mast cells, basophils, dendritic cells, eosinophils, natural killer cells, monocytes, and macrophages are different innate cells. Acquired or Adaptive Immunity. It is the third line of defense and produced in exposure to foreign substances.
It is a specific immune system that consists of highly specialised systemic cells and processes that eliminate pathogens and prevent its growth. It adapts to the type of threat that we are exposed to; it produces lymphocytes and antibodies during second exposure which are specific to pathogens when exposed to the first exposure.
It is slower in the process but more potent than innate immunity. Immunological memory of the first encounter is produced while second exposure, thus lymphocytes and antibodies are present to eliminate pathogens. SImilarly for subsequent exposures. B lymphocytes and T lymphocytes are two kinds of lymphocytes. Humoral immunity due to B-lymphocytes.
Cellular immunity due to the T-lymphocytes. After the initial infection, the body builds immunity against the disease. This natural active immunity is why people who catch chicken pox are immune for many decades against the disease. Also known as artificial active immunity, a person can build a resistance to a disease following an immunization.
An immunization is defined as the process by which someone becomes protected against a specific disease via the administration of a vaccine. Vaccines use a weakened or dead form of a disease to stimulate an immune response. Vaccines are typically administered using an injection. However, there are vaccinations administered via the mouth or as a nasal spray.
This includes forming new antibodies and memory cells specific to that pathogen. In the future, if the body is exposed to said pathogen, antibodies will be created to protect the body. Vaccination and immunity are essential for keeping large populations of people safe from infectious diseases.
For instance, the flu vaccine prevents millions of people from becoming infected with the flu every year. Passive immunity is protection from a disease provided by antibodies created outside of the body. Next, the scientists showed that they could cure diphtheria in an animal by injecting it with the blood products of an immunized animal.
They soon moved to testing the approach on humans and were able to show that blood products from immunized animals could treat diphtheria in humans. The antibody-containing blood-derived substance was called diphtheria antitoxin, and public boards of health and commercial enterprises began producing and distributing it from onward. Kitasato, von Behring, and other scientists then devoted their attention to treatment of tetanus, smallpox, and bubonic plague with antibody-containing blood products.
The use of antibodies to treat specific diseases led to attempts to develop immunizations against the diseases. Their pioneering work, along with advances in the separation of the antibody-containing blood component, led to many studies on the effectiveness of antibody preparations for immunization against measles and infectious hepatitis.
Before the polio vaccine was licensed, health officials had hopes for the use of gamma globulin an antibody-containing blood product to prevent the disease. William M. He showed that administration of gamma globulin containing known poliovirus antibodies could prevent cases of paralytic polio. However, the limited availability of gamma globulin, and the short-term protection it offered, meant that the treatment could not be used on a wide scale.
The licensure of the inactivated Salk polio vaccine in made reliance on gamma globulin for poliovirus immunization unnecessary. Today, patients may be treated with antibodies when they are ill with diphtheria or cytomegalovirus. Or, antibody treatment may be used as a preventive measure after exposure to a pathogen to try to stop illness from developing such as with respiratory syncytial virus [RSV], measles, tetanus, hepatitis A, hepatitis B, rabies, or chickenpox.
Antibody treatment may not be used for routine cases of these diseases, but it may be beneficial to high-risk individuals, such as people with immune system deficiencies. Vaccines typically need time weeks or months to produce protective immunity in an individual and may require several doses over a certain period of time to achieve optimum protection. Passive immunization, however, has an advantage in that it is quick acting, producing an immune response within hours or days, faster than a vaccine.
Additionally, passive immunization can override a deficient immune system, which is especially helpful in someone who does not respond to immunization. Antibodies, however, have certain disadvantages. First, antibodies can be difficult and costly to produce. Although new techniques can help produce antibodies in the laboratory, in most cases antibodies to infectious diseases must be harvested from the blood of hundreds or thousands of human donors.
Or, they must be obtained from the blood of immune animals as with antibodies that neutralize snake venoms. In the case of antibodies harvested from animals, serious allergic reactions can develop in the recipient. Another disadvantage is that many antibody treatments must be given via intravenous injection, which is a more time-consuming and potentially complicated procedure than the injection of a vaccine. Finally, the immunity conferred by passive immunization is short lived: it does not lead to the formation of long-lasting memory immune cells.
In certain cases, passive and active immunity may be used together. For example, a person bitten by a rabid animal might receive rabies antibodies passive immunization to create an immediate response and rabies vaccine active immunity to elicit a long-lasting response to this slowly reproducing virus.
These antibodies have wide-ranging potential applications to infectious disease and other types of diseases. Monoclonal antibodies were first created by researchers Cesar Milstein, PhD , and Georges Kohler, PhD , who combined short-lived antibody-producing mouse spleen cells which had been exposed to a certain antigen with long-lived mouse tumor cells.
The combined cells produced antibodies to the targeted antigen. To date, only one MAb treatment is commercially available for the prevention of an infectious disease. Scientists are researching other new technologies for producing antibodies in the laboratory, such as recombinant systems using yeast cells or viruses and systems combining human cells and mouse cells, or human DNA and mouse DNA. Bioterror threats In the event of the deliberate release of an infectious biological agent, biosecurity experts have suggested that passive immunization could play a role in emergency response.
The advantage of using antibodies rather than vaccines to respond to a bioterror event is that antibodies provide immediate protection, whereas a protective response generated by a vaccine is not immediate and in some cases may depend on a booster dose given at a later date. Candidates for this potential application of passive immunization include botulinum toxin, tularemia, anthrax, and plague. For most of these targets, only animal studies have been conducted, and so the use of passive immunization in potential bioterror events is still in experimental stages.
Antibodies were one of the first tools used against specific infectious diseases. As antibiotics came to be widely used, and as vaccines were developed, the use of passive immunization became less common. Even today, however, antibodies play a role against infectious disease when physicians use antibodies to achieve passive immunity and to treat certain diseases in patients. Scientists are investigating new applications for passive immunization and antibody treatment as well as new and more efficient methods of creating antibodies.
Casadevall, A. Passive antibody administration immediate immunity as a specific defense against biological weapons. Facebook Twitter LinkedIn Syndicate. Immunity Types. Minus Related Pages. Links with this icon indicate that you are leaving the CDC website. Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
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