Adverse Events Associated with Childhood Vaccines Evidence Bearing on Causality (1994) / Chapter Skim
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4 Immunologic Reactions
4 Immunologic Reactions
Pages 59-66
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From page 59... ...
A classification of immunologic reactions that can cause disease has been proposed by Coombs and Gell (1968~. Four reactions make up the classification: type I, immediate hypersensitivity, the most serious clinical manifestation of which is anaphylaxis; type II, reaction of antibody with tissue antigens; type III, Arthus-type reaction, caused by deposition of antigen-antibody complexes in tissues, leading to the tissue-damaging effects of complement and leukocytes; and type IV, delayed-type hypersensitivity, which is mediated largely by T lymphocytes and macrophages.
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From page 60... ...
, and presumably upon the rate with which the antigen enters the circulation, localized or systemic symptoms may not be expressed for minutes or a few hours (Dolovich et al., 1973; Pearlman and Bierman, 1989~. In proposed changes to the Vaccine Injury Table, which is used by the Vaccine Injury Compensation Program to determine eligibility for compensation for vaccine-induced injuries, the time frame for the onset of anaphylaxis/anaphylactic shock following vaccination has been set at 4 hours (U.S.
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From page 61... ...
In this reaction, immune complexes in the walls of blood vessels initiate an inflammatory reaction involving complement and leukocytes, particularly neutrophils. Tissue sections show acute inflammation, and profound tissue destruction can occur.
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From page 62... ...
As with IgG antibody responses, this form of hypersensitivity represents the normal immunologic response to certain types of foreign antigen, and it is seen commonly after recovery from natural infections. On first exposure, the response peaks after about 3 weeks; on reexposure, the response typically peaks after 24 to 48 hours.
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From page 63... ...
During a single episode of upper respiratory viral infection, humans are exposed, depending on the particular virus involved, to between 4 and 10 foreign proteins, and during a routine "strep throat" infection, to between 25 and 50. Moreover, acquisition of a single new bacterium in the gastrointestinal tract, a common and normal event in consumption of everyday foods, or acquisition of one of the apparently harmless bacteria that inhabit the mouth and nose exposes the immune system to at least 50 potential antigens (Goldblatt et al., 1990~.
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From page 64... ...
, and there have been concerns that live attenuated viral vaccines might have a similar effect. Soon after the live attenuated measles vaccine was developed, it was shown that immunization temporarily suppressed the delayed-type hypersensitivity skin test response to purified protein derivative, an index of cell-mediated immunity to Mycobacterium tuberculosis (Brody and McAlister, 1964; Starr and Berkovich, 1964~.
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From page 65... ...
Kabat EA. A quantitative study of the Arthus phenomenon induced passively in the guinea pig.
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From page 66... ...
Measles virus vaccination of measles seropositive individuals suppresses lymphocyte proliferation and chemotactic factor production. Clinical Immunology and Immunopathology 1981;21:341-350.
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