In vitro evaluation methods for Clostridium botulinum type C and D vaccines.
Reagents were prepared for use in ELISAs to determine the concentration of the antigenic components of Clostridium botulinum type C and D. The results obtained were compared with the L+dose assay and a good correlation was found between the two assays for measurement of the C and D neurotoxin concentration. These ELISAs were also used to determine the concentration of the neurotoxins in toxoid form. The relationship between the C neurotoxin dose, in toxoid form, and the immune response in guinea pigs could be deduced from the data obtained. The relationship for the D neurotoxin was not that clear, as the same concentration of the antigen resulted in variable potency values. However, these ELISAs can be used to formulate the concentration of the C and D components in the final bivalent vaccine. Replacement of the preliminary potency assay on the monovalent components after production with the in vitro assays will shorten the total production time of the vaccine by about 60 days. The economical and ethical implications are the reduction in the use of animals to evaluate the vaccine.
Bacterial Vaccine Development Unit, Onderstepoort Veterinary Institute, South Africa. charlotte@moon.ovi.ac.za
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Ellis
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Hamman
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Harris
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de Bruin
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology*; D001905:Botulinum Toxins / Q000276:immunology*; D003014:Clostridium botulinum / Q000276:immunology*; D005069:Evaluation Studies as Topic; D006168:Guinea Pigs; D011817:Rabbits
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; C096325:botulinum toxin type D; D001905:Botulinum Toxins; C096324:botulinum toxin type C