protection against infectious disease conferred either by the immune response generated by immunization or previous infection or by other non-immunologic factors
Protection against a disease There are two types of immunity, passive and active Immunity is indicated by the presence of antibodies in the blood and can be determined with a laboratory test See active and passive immunity
Freedom or exemption from any charge, duty, obligation, office, tax, imposition, penalty, or service; a particular privilege; as, the immunities of the free cities of Germany; the immunities of the clergy
Legal protection from liability There are many categories of immunity in civil and criminal law For example, sovereign immunity protects government agencies from civil liability and judicial immunity protects judges acting in their official capacities
(From Latin immunitas: "freedom from public service ") Freedom or exemption from a burden or duty, such as from the obligation to appear before a court
A constitutional privilege from arrest -- except for treason, felony, or breach of the peace -- 15 days prior to, during, and in returning from a session and for words used in any speech or debate
An exemption that a person (individual or corporate) enjoys from the normal operation of the law such as a legal duty or liability, either criminal or civil For example, diplomats enjoy "diplomatic immunity" which means that they cannot be prosecuted for crimes committed during their tenure as diplomat Another example of an immunity is where a witness agrees to testify only if the testimony cannot be used at some later date during a hearing against the witness
Ability to resist attack or overcome infection by invading microbes or larger parasites. Immunity is based on the proper functioning of the body's immune system. In natural or innate immunity, immune mechanisms present at birth work against a wide variety of microbes whether or not they have been encountered before. Acquired immune responses, tailored to act against a specific microbe or its products, are stimulated by the prior presence of that microbe. Previous infection with a particular pathogen, as well as vaccines, produce this type of immunity. The mechanisms of innate immunity include physical barriers (including the skin) and chemical barriers (such as bactericidal enzymes present in saliva). Microbes that penetrate the body's natural barriers encounter substances (such as interferon) that inhibit their growth or reproduction. Phagocytes (particle-engulfing cells) surround and destroy invading microbes, and natural killer cells pierce the microbe's outer membrane. Innate immunity does not confer lasting resistance, or immunity, to the body. Acquired immunity is based on the recognition of antigen by B cells and T cells and is activated when innate mechanisms are insufficient to stem further invasion by pathogens. Killer or cytotoxic T cells destroy infected and foreign cells. Helper T cells induce B cells stimulated by the presence of antigen to proliferate into antibody-secreting cells, or plasma cells. Antibodies produced by plasma cells bind to antigen-bearing cells, marking them for destruction. Acquired immunity relies on the long-term survival of sensitized T and B memory cells, which can proliferate quickly upon reinfection by the same pathogen. See also immunodeficiency; immunology; leukocyte; reticuloendothelial system. In law, exemption or freedom from liability. Under international treaty, a diplomatic representative is exempt from local laws, both civil and criminal. In many countries, judges, legislators, and government officials, including the heads of state, enjoy limited or absolute immunity at home to protect them from personal liability for wrongful acts or omissions that arise from the performance of their duties. A public prosecutor may grant immunity from prosecution to a witness who is suspected of criminal activity in return for testimony against other suspected criminals
Immunity has special meaning in a 911 context No CMRS or 911 provider, its employees, officers or agents is criminally liable or liable for any damages in a civil action for injuries, death or loss to person or property resulting from any act or omission in connection with the development, adoption, implementation, maintenance, enhancement or operation of E911 service, unless such damage or injury was intentional or the result of gross negligence or willful or wanton conduct (Back to top )
the protection of members of Parliament and others from civil or criminal action in relation to their participation in parliamentary proceedings, and the protection of parliamentary proceedings from impeachment or question in the courts (see also privilege, parliamentary)
freedom from a natural or usual liability or obligation, as in: Even though he admitted the accident was his fault, the Ambassador claimed diplomatic immunity and could not be sued