Vaccination and challenge experiments are a necessity for the
development of vaccines against bovine TB. However, these exper-iments involve the use of large animal BSL3 facilities. Whilst
necessary, due to their nature, these facilities are expensive to run
and limited in number and therefore represent a bottle neck for the
testing of vaccine candidates. Development of a model in the target
species, cattle, for prioritizing vaccines under lower containment
conditions would save money as BSL2 facilities are cheaper to run
than BSL3 facilities. Being an attenuated strain of M. bovis it would
be expected that cattle would at some stage control BCG and therefore the BCG challenge experiments would be shorter than standard
virulent M. bovis challenge experiments. Further, by reducing the