VMD making headway with 3Rs concept
Historically, challenge tests with lethal endpoints have been used to assess batch potency testing for some vaccines such as rabies, leptospira, clostridial and various fish vaccines. Serological and/or in vitro alternative methods have been developed and implemented for some vaccines. However, some vaccines in these categories still rely on the challenge test. The London-based Veterinary Medicines Directorate (VMD) has questioned why this is the case.