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Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The potency tests for bacterial vaccines are quite diverse. For some products (pertussis, cholera, anthrax, typhoid and BCG vaccines) these are specified as Additional Standards in the Code of Federal Regulations. For other products (tetanus and diphtheria toxoids, plague vaccine) the testing is done according to so-called Minimum Requirements, which have less regulatory authority than Additional Standards. Still other products (e.g., polysaccharide conjugate vaccines, acellular pertussis vaccine, live oral typhoid) are tested according to individualized criteria that are contained in their specific Product License Applications. For some products there is inadequate knowledge of the pathogenic mechanisms and/or protective factors to design valid in vitro potency tests. In these cases, animal testing with subsequent serologic evaluation or challenge testing is often necessary. Examples would include vaccines such as cholera and plague vaccines. The FDA supports the elimination of animal testing when suitable alternatives are available. Thus, many of the potency tests, especially for newer products, rely on in vitro characterization. For example, the immunogenicity of conventional polysaccharide vaccines is largely proportional to their molecular weight. Potency testing therefore relies heavily on physical characterization in terms of composition, molecular weight, and quantity.
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PMID:Potency testing of bacterial vaccines for human use. 811 90

While it has been said that PCR is likely to replace DFA as the test of choice, accessibility to and cost of the technique may limit the number of laboratories that are able to implement the process. Still, the advantage of DFA staining relative to other diagnostic methods, including PCR, is the provision of a rapid result and lower overall cost. The laboratory diagnosis of pertussis remains problematic, and polyclonal DFA reagents for its detection have brought into question the utility of DFA. However, the integration of a commercially available monoclonal DFA reagent, in combination with the development and standardization of existing procedures, should provide clinicians with an improved method for the diagnosis and epidemiology of pertussis.
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PMID:Use of monoclonal fluorescent antibodies for the detection of B. pertussis and B. parapertussis. 1101 May 84

Pertussis vaccines are routinely administered to infants to protect them from whooping cough. Still, an adequate safety test for pertussis toxin (PT), one of the main antigens in these vaccines, is not available. The histamine sensitization test is currently the only assay accepted by regulatory authorities to test for the absence of active PT in vaccines. This is however, a lethal animal test with poor reproducibility. In addition, it is not clear whether the assumed underlying mechanism, i.e., ADP-ribosylation of G proteins, is the only effect that should be considered in safety evaluation of PT. The in vitro safety test for PT that we developed is based on the clinical effects of PT in humans. For this, human cell lines were chosen based on the cell types involved in the clinical effects of PT. These cell lines were exposed to PT and analyzed by microarray. In this review, we discuss the clinical effects of PT and the mechanisms that underlie them. The approach taken may provide as an example for other situations in which an in vitro assay based on clinical effects in humans is required.
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PMID:Toward a mechanism-based in vitro safety test for pertussis toxin. 2455 55

Pertussis, a highly contagious respiratory infection, remains a public health priority despite the availability of vaccines for 70 years. Still a leading cause of mortality in developing countries, pertussis has re-emerged in several developed countries with high vaccination coverage. Resurgence of pertussis in these countries has routinely been attributed to increased awareness of the disease, imperfect vaccinal protection or high infection rates in adults. In this review, we first present 1980-2012 incidence data from 63 countries and show that pertussis resurgence is not universal. We further argue that the large geographical variation in trends probably precludes a simple explanation, such as the transition from whole-cell to acellular pertussis vaccines. Reviewing available evidence, we then propose that prevailing views on pertussis epidemiology are inconsistent with both historical and contemporary data. Indeed, we summarize epidemiological evidence showing that natural infection and vaccination both appear to provide long-term protection against transmission and disease, so that previously infected or vaccinated adults contribute little to overall transmission at a population level. Finally, we identify several promising avenues that may lead to a consistent explanation of global pertussis epidemiology and to more effective control strategies.
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PMID:The pertussis enigma: reconciling epidemiology, immunology and evolution. 2676 1