Collaborative study for the establishment of a European Pharmacopoeia Biological Reference Preparation for Clostridia antiserum for serological potency testing of veterinary clostridial vaccines.

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.

Veterinary vaccines: In-VITRO--International Veterinary Industry Test Replacement Organisation.

The International Veterinary Industry Test Replacement Organisation (In-VITRO) was established in 1995 with the aim of developing, validating and harmonising in vitro alternatives to replace in vivo methods for in-process and potency testing of veterinary clostridial vaccines. The emphasis has been on the reduction of animal usage in the Clostridium chauvoei potency assay and its eventual replacement by an in vitro assay. Replacement of the toxin neutralisation assay for Cl.

Alternatives to in vivo potency and protection tests for veterinary vaccines.

I firmly believe that we should use animal-based studies only when there is no satisfactory alternative. However, the development of meaningful alternatives requires good science. Regrettably, all too often, we can see examples of potency tests which have not been properly developed and validated and are therefore incapable of providing us with the information that they should be designed to provide.

Reducing the use of the target animal batch safety test for veterinary vaccines.

The need to submit each batch of every veterinary vaccine to a target animal safety test is questioned. It is proposed that a risk/benefit analysis should be conducted, on a product by product basis, to determine whether the continued application of this test to each batch of a product is beneficial and justified. For an established product, the analysis should consider: the number of batches manufactured; the length of time for which the product has been manufactured; the testing experience and the incidence of reported adverse reactions; the level of GMP compliance and the standard of QA practised by the manufacturer; the method and conditions of manufacture; the use of animals for other batch tests; the recommendations for the use of the product.