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Published on: December 19, 2020
International collaborative study for establishment of the 2nd WHO International Standard for Haemophilus influenzae
Fatme Mawas1, Karena Burkin1, Thomas Dougall2
1Division of Bacteriology, NIBSC, Medicines and Healthcare Products Regulatory Agency, Blanche Lane, Potters Bar, Hertfordshire EN6 3QG, UK.
Abstract:
In this report we present the results of a collaborative study for the preparation and calibration of a replacement International Standard (IS) for Haemophilus influenzae type b polysaccharide (polyribosyl ribitol phosphate; 5-d-ribitol-(1 → 1)-β-d-ribose-3-phosphate; PRP). Two candidate preparations were evaluated. Thirteen laboratories from 9 different countries participated in the collaborative study to assess the suitability and determine the PRP content of two candidate standards. On the basis of the results from this study, Candidate 2 (NIBSC code 12/306) has been established as the 2nd WHO IS for PRP by the Expert Committee of Biological Standards of the World Health Organisation with a content of 4.904 ± 0.185mg/ampoule, as determined by the ribose assays carried out by 11 of the participating laboratories.
