It is likely that TB is in the soil so cattle would continue to contract TB even if all the badgers, deer etc. were tested then immunised or culled depending on their test results. The weak (runts), sick and wounded cattle (open wounds or small cuts) would be most vulnerable to contracting TB from the soil, dust etc.. The recent outbreak of polio in children not vaccinated due to the conflict in Syria shows that these diseases are always around.
The best prevention would probably be testing of all cattle, culling the infected and vaccinating the healthy. However, apparently the current test used for cattle would become invalid after vaccination, I assume this is because it is unable to differentiate between active TB and antibodies to the vaccine. Until such a test becomes available vaccination is not an option.
A comprehensive badger TB vaccination program would be a massive undertaking at enormous cost. Badgers are wild and not all of them and their cubs would be caught. They would have to be kept in captivity pending the test results. In my view, vaccinating an already infected badger could result in the emergence of a stronger strain of TB. Also, if its deemed not safe to vaccinate cattle the same would be true of badgers.
Deer also contract and spread TB. I have seen wild deer wandering around fields with cattle in England. Why are they not being targeted?
