The immune system is the body's defense against infections. The immune (ih-MYOON) system attacks germs and helps keep us healthy. Show What Are the Parts of the Immune System?Many cells and organs work together to protect the body. White blood cells, also called leukocytes (LOO-kuh-sytes), play an important role in the immune system. Some types of white blood cells, called phagocytes (FAH-guh-sytes), chew up invading organisms. Others, called lymphocytes (LIM-fuh-sytes), help the body remember the invaders and destroy them. One type of phagocyte is the neutrophil (NOO-truh-fil), which fights bacteria. When someone might have bacterial infection, doctors can order a blood test to see if it caused the body to have lots of neutrophils. Other types of phagocytes do their own jobs to make sure that the body responds to invaders. The two kinds of lymphocytes are B lymphocytes and T lymphocytes. Lymphocytes start out in the bone marrow and either stay there and mature into B cells, or go to the thymus gland to mature into T cells. B lymphocytes are like the body's military intelligence system — they find their targets and send defenses to lock onto them. T cells are like the soldiers — they destroy the invaders that the intelligence system finds. How Does the Immune System Work?When the body senses foreign substances (called antigens), the immune system works to recognize the antigens and get rid of them. B lymphocytes are triggered to make antibodies (also called immunoglobulins). These proteins lock onto specific antigens. After they're made, antibodies usually stay in our bodies in case we have to fight the same germ again. That's why someone who gets sick with a disease, like chickenpox, usually won't get sick from it again. Can be difficult to transport due to requirement to maintain conditions. For instance, refrigeration. Shimizu et al. (2004) andKamboj and Sepkowitz (2007)Killed or inactivated1. Completely safe as the pathogen cannot revert back to virulence. 2.Inexpensive. 3.No special requirements necessary for carrying the vaccine. 4.Almost all antigens present in pathogen are available to the host. Baxter (2007)1.Requirement of booster. 2.Not effective against intracellular pathogens. 3.Requirement of adjuvants leading to adjuvant-related complications. Morefield et al. (2005) andBaxter (2007)Protein subunitExtremely safe and can be used even on immunocompromised, stressed and even brood stocks.Problems associated with adjuvants, boosters and local-site reactions.Baxter (2007)DNA vaccine1. Inexpensive, stable, easy to transport and handle. 2.Long-term protection. 3.If vaccine is a plasmid, a mixture of many plasmids can be used to form a broad spectrum vaccine. 4.Considered to be safe although it activates different leukocyte population. Sasaki et al. (2003)Alarcon et al. (1999) Khan (2013) Robinson and Pertmer (2000)1. Exclusive for protein antigens. 2.May induce immunological tolerance. 3.Since the DNA is foreign it may induce production of antibodies against. 4.Mostly by injection route. Kindt et al. (2007) andFerrera et al. (2007), Khan (2009) View chapterPurchase book Read full chapter URL: https://www.sciencedirect.com/science/article/pii/B9780128045640000041 Vaccines, Antivirals, and the Beneficial Uses of VirusesJennifer Louten, in Essential Human Virology, 2016 8.1.4 Passive ImmunityThe types of vaccinations described above all provide active immunity, meaning that the person’s own immune system responds to the pathogen by generating memory cells that will be reactivated upon subsequent exposures to the virus. On the other hand, passive immunity is the transfer of immune system components, primarily antibodies (immunoglobulins), into a person. Without plasma cells to continue producing them, transferred antibodies will eventually break down and become nonfunctional, but they serve several purposes. First, they are an immediate response. If a person is bitten by a rabid bat, the rabies vaccine is given but takes weeks to generate plasma cells that produce antibody. Transferred human rabies immunoglobulin immediately neutralizes virions to prevent continued infection. Antibodies can also be given to immunocompromised individuals who may not be able to be vaccinated but are exposed to virus that could be of concern in their state. Transferred immunoglobulin may partially or completely protect the individual. Several immunoglobulins have been approved for use as passive therapy in the United States. Often, they can be recognized because their names end in “IG,” the abbreviation for “immunoglobulin.” “IVIG” refers to those immunoglobulins that are administered intravenously. Immunoglobulin preparations are available against HBV, varicella zoster virus, vaccinia virus, and respiratory syncytial virus. (They are also used against venoms from scorpions, black widow spiders, vipers, and rattlesnakes.) Who develops active immunity?There are two types of adaptive immunity: active and passive. Active Immunity - antibodies that develop in a person's own immune system after the body is exposed to an antigen through a disease or when you get an immunization (i.e. a flu shot). This type of immunity lasts for a long time.
Which patient will develop passive immunity?Passive immunity is provided when a person is given antibodies to a disease rather than producing them through his or her own immune system. A newborn baby acquires passive immunity from its mother through the placenta.
What is an example of active immunity?Examples of active immunity include a person's resistance to strep throat due to a previous infection or a person's immunity to polio due to the polio vaccine. Types of active immunity can either be natural active immunity or artificial active immunity.
Where is active immunity produced?Active vs passive immunity table. |
