The use of the toxin binding inhibition test for potency testing of Clostridium novyi type B alpha toxoid vaccines
Luick, K.; Gottschaldt, J.; Schulze, F.; Werner, E.; Erler, W.; Borrmann, E.
Deutsche Tierärztliche Wochenschrift 109(4): 178-182
2002
ISSN/ISBN: 0341-6593 PMID: 11998370 Document Number: 547636
The toxin binding inhibition test (ToBI) was developed for potency testing of Clostridium novyi type B alpha toxoid containing veterinary vaccines to replace the currently used toxin neutralization test in mice (TNT). The antitoxin titres of rabbit sera (AN-, HV- and SP sera) were determined with ToBI using the international reference serum with known antitoxin titre. In order to show the validity of the methods, the results were compared with those of the manufacturers/regulatory authorities and correlation coefficients were calculated. The correlation coefficients were r=0,93 (AN sera), r=0,73 (HV sera) and r=0,85 (SP sera). All correlations were statistically significant. The specificity of the methods could be proved using heterologeous antisera. The results of the ToBI were reproducible. Thus, the ToBI offers a suitable in vitro method for the determination of the antitoxin titre of rabbit antisera as an alternative to the toxin neutralization in mice for potency testing of vaccines containing C. novyi type B alpha toxoid.