Immunity passive acquired

This is subdivided into actively acquired and passively acquired immunity, each of which may be induced naturally or artificially. 

Passively acquired immunity involves no work on the part of the body s defence mechanisms, and produces immediate protection of short duration. 

The theoretieal baekground whieh underlies immunity to infection has been discussed in detail in Chapter 14. Immunity to infeetion may be passively acquired through the receipt of preformed, proteetive antibodies or it may be aetively acquired through an immune response following deliberate or accidental exposure to microorganisms or their eomponent parts. Aetive aequired immunity might involve either or both humoral and cell-mediated responses. 

Passive Acquired Immunity Antibodies from a human or animal source are administered to the patient. 

Immune systems in animals and plants are quite different. There are two types of immune systems in animals (1) innate, so-called non-specific or passive immunity (2) adaptive, so-called specifically acquired , active, or cell-mediated immunity. Innate immunity is based on barriers to infectious agents and adaptive immunity is based on multiplicative and specific antibody release after contact with an antigen (infectious agent). The so-called memory cells in animals respond to secondary contact with an antigen. 

When antibodies produced in one body are transferred to another to induce protection against disease, it is known as passive immunity. It can be acquired naturally i.e. in foetus receiving mother s antibodies through placenta or artificially by administration from outside in the form of antisera containing antibodies. 

Neonates have the ability to absorb intact proteins. This ability, which is rapidly lost, is of immense importance because it allows the newborn animal to acquire passive immunity by absorbing immunoglobulins in colostral milk. 

The immune system may be described as innate, passive or acquired (adaptive). Acquired immunity is further divided into humoral and ceU-mediated types. 

Naturally acquired passive immunity Temporary nccmti protection from malemal IgC pa.sses to the fetus in utcntib type of immunity is not long-lasting. 

Artificially acquired passive immunity. An Ab is gi [Pg.206]

Immunologicals are all medicines which are either allergens defined cis products used to identify or provoke a specific modification to acquire an immunological response to an antiallergic agent, or vaccines, toxins or sera defined as all agents used to provoke an active or passive immunity to diagnose the state of immunity. 

Short-term immunity may be achieved by passive vaccination, or the transfer of protective antibodies into the recipient. Vaccination is currently being explored as a therapeutic approach for inducing needed immune responses in individuals who have acquired a disease (e.g., cancer or Alzheimer s disease)... 

Passive immunity is transient—lasting no more than several weeks to a few months. The individual does not mount his or her own immune response to antigens. Acquired passive immunity is important when time does not permit active vaccination alone, when the exposed individual is at high risk for complications of the disease, or when the person suffers from an immune system deficiency that renders that person unable to produce an effective immune response. 

Passive immunization is accomplished by transferring antibodies from a resistant to a susceptible host. Passively transferred antibodies confer a temporary but immediate resistance to infection, but are gradually catabolized by the susceptible host. Once passive protection wanes, the recipient becomes susceptible to infection again. Passively transferred antibodies can be acquired by the recipient either transplacentally and transcolostrally as in neonates, or by injection of purified antibodies from a resistant donor into a susceptible recipient. 

Passive immunity is induced by injection of serum taken from an individual already immune to a particular antigen it can also be acquired by the transfer of maternal antibodies to offspring via the placenta or breast milk (seecolostrum). Active immunity tends to be long-lasting passive immunity is short-lived. See also autoimmunity. 

Artificially acquired passive immunity When antibodies made by other hosts are introduced into a new host, e.g., via mother s milk or shots of gamma globulin. 

---