Vacinating a cow makes it appear to have TB and is currently illegal
http://www.tbfreeengl...we-vaccinate-cattle-/
This "unproven" is plying with words - there is no *numerical* figure on it but the krebbs report says:
//The sum of evidence strongly supports the view that, in Britain , badgers are a significant source of infection in cattle. Most of this evidence is indirect, consisting of correlations rather than demonstrations of cause and effect; but in total the available evidence, including the effects of completely removing badgers from certain areas, is compelling.//
http://www.bovinetb.info/docs/krebs.pdf
Such correlation evidence is similar to that first used to link smoking to lung cancer