title: Collaborative study for the establishment of a European Pharmacopoeia Biological Reference Preparation for Clostridia antiserum for serological potency testing of veterinary clostridial vaccines.
abstract: The European Directorate for the Quality of Medicines (EDQM) has organised an international collaborative study, divided in two phases, aimed at producing and establishing a suitable reference serum for serological potency testing of clostridial vaccines for batch consistency demonstration. In phase 1 a series of pools produced from sera provided by each manufacturer and raised against the broadest range of antigens possible were blended to obtain TN titres which were representative of the range normally elicited by the vaccines under test. Detailed statistical analysis of the data was not possible since only a few laboratories were able to participate and because limited replication of the assays was possible. Nevertheless, sufficient data were collected to conclude that the blend of sera would provide a suitable reference material for use by all manufacturers and regulatory authorities in respect of in vitro assay methods for the five components for which it was primarily designed, i.e. Clostridium (C.) perfringens beta and epsilon, septicum, novy and tetani. On the basis of these results a production scale blend of the serum pools was prepared, filled and freeze-dried by EDQM as a single batch, referred to as candidate (c) Ph. Eur. Biological Reference Preparation (BRP). In phase 2 of the study a larger group of laboratories, including both manufacturers and official medicines control laboratories (OMCL), were invited to participate in a study comparing the activity of the proposed rabbit multicomponent reference serum with the existing equine monovalent World Health Organization (WHO) International Standard (IS). These studies necessarily were conducted according to the methods described in the currently applicable monographs i.e. by toxin neutralisation test in mice (TN) to provide a definitive value for the antitoxin activity of the reference preparation in respect of the five components studied.
authors.affiliation: Trawsnant, Llandysul, United Kingdom.
authors.forename: R
authors.initials: R
authors.lastname: Lucken
authors.forename: A
authors.initials: A
authors.lastname: Daas
authors.forename: M E
authors.initials: ME
authors.lastname: Behr-Gross
mesh_terms: D000826:Animal Testing Alternatives; D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology*; D001427:Bacterial Toxins / Q000276:immunology*; D001428:Bacterial Vaccines; D003013:Clostridium / Q000276:immunology*; D005060:Europe; D007106:Immune Sera; D051379:Mice; D010602:Pharmacopoeias as Topic; D011817:Rabbits; D012015:Reference Standards; D012107:Research Design
chemical_list: D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D007106:Immune Sera