Replacement of In Vivo Leptospirosis Vaccine Potency Testing in the United States
A 2012 workshop co-organized by NIEHS, USDA, and partner organizations sought to develop an international strategy to replace the use of animals in tests required during the assessment of veterinary leptospirosis vaccines (Johnson et al. 2013). Workshop participants gave special attention to the barriers remaining to replace the in vivo vaccine potency test in hamsters. At the time of the workshop, in vitro methods were not widely used as replacements for the in vivo potency test, but advances in both technology and regulatory arenas have since increased their acceptance and use. NIEHS and USDA scientists prepared a review of recent progress (Rogers et al. 2022) to reduce the use of hamsters in leptospirosis vaccine batch potency testing, as well as obstacles remaining to completely replace the use of hamsters with accepted in vitro methods.