Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A good correlation was observed between mouse intracerebral potency in terms of International Units and 50 per cent histamine sensitizing dose (HSD50) of various types of pertussis vaccine. The correlation was significant irrespective of the inactivating agent used for the preparation of pertussis vaccine. If the potency of the vaccine increased, the HSD50 decreased and vice versa showing a negative correlation between potency and HSD50. The relative histamine sensitizing (HS) activities of various types of pertussis vaccines in comparison to that of heat inactivated pertussis vaccine (HIPV) obtained in different experiments were very similar although the HSD50 values of same types of vaccines obtained in these experiments varied greatly. The conventional HIPV preparations having potency around 8 IU per 40 x 10(9) organisms had HSD50 values in the range of 1.0 to 2.2 x 10(8) organisms. The estimation of HSD50 of pertussis vaccine has been found to be a useful measure of the toxicity of the vaccine and also correlates well with the potency of the vaccine.
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PMID:Correlation between mouse intracerebral potency & 50 per cent histamine sensitizing dose of pertussis vaccine. 247 91

Pertussis toxin (PT) in its detoxified form is an important antigenic component of both acellular and whole cell pertussis vaccines. Limits on the content of active PT in acellular vaccines are set in official monographs (EP, WHO, USP) and evidence of compliance is therefore, required by regulatory authorities. The two assay methods which are currently used by most manufacturers and official national control laboratories to monitor residual PT activity in acellular pertussis vaccines (and also in whole cell vaccines) are histamine sensitising (HIST) assays and Chinese hamster ovary (CHO) cell assays. Currently, different reference preparations of PT are used by individual laboratories for these tests. We therefore organised an international collaborative study to examine, by these two assay methods, two freeze-dried purified preparations of PT, one preparation in ampoules coded JNIH-5 and one preparation in ampoules coded 90/518, together with in-house reference (IHR) preparations in current use. Data from this study confirm that both JNIH-5 and 90/518 show biological activity both in HIST assays and in CHO-cell assays. Both HSD50 and ED50 values obtained in this study differ significantly between laboratories and thus show that biological activity is not determined by the nominal masses of preparations. Estimates of relative potency of 90/518 in terms of JNIH-5 per ampoule for the HIST assays do not differ significantly between laboratories. The overall mean estimates of relative potency of 90/518 in terms of JNIH-5 do not differ significantly between the two methods. Data from this study further indicate that the biological activity of different preparations was not directly related to their stated protein content. The use of protein content to indicate the level of PT activity in different preparations would give misleading results. Thus, use of a common standard is shown to greatly improve between laboratory agreement of estimates.
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PMID:Comparison of the bioactivity of reference preparations for assaying Bordetella pertussis toxin activity in vaccines by the histamine sensitisation and Chinese hamster ovary-cell tests: assessment of validity of expression of activity in terms of protein concentration. 1229 99