International regulatory requirements for Leptospira vaccine potency testing. Roundtable: current requirements and opportunity for harmonization.

Progress continues to be made in the ongoing efforts to replace, reduce, or refine the use of laboratory animals for Leptospira vaccine potency testing in certain markets/regions. Leptospira-containing vaccines, as with many veterinary vaccines, are manufactured and distributed both on a regional basis by local manufacturers and internationally by large multinational firms. Three general scenarios exist for the international testing and distribution of veterinary vaccines including: 1) the importing country recognizes the country of origin's testing and batch release data with no additional testing; 2) the importing country requires the manufacturer to conduct a specific potency assay based on the current importing market's regulations for the importing country or 3) the importing country requires retesting of the product in country prior to distribution. Scenarios 2 and 3 both have the potential to significantly increase the usage of laboratory animals for what may be considered redundant testing. Specific requirements for the importation of Leptospira vaccines in the United States, Europe, and Mexico were presented as well as efforts to reduce the use of laboratory animal testing through the availability of internationally recognized tests.