Mycobacterium bovis causes tuberculosis (TB) in cattle, but it can also infect wild animals and, occasionally, humans. In the United Kingdom, badgers are thought to spread M. bovis between farms, thereby hindering disease eradication. Two controversial programmes are now underway to tackle the problem: a badger vaccination trial in Wales and the culling of wild badgers in affected areas of southwest England. Opponents question the scientific and economic rationale of both programmes. A previous culling trial resulted in only a 16% reduction of new bovine TB cases. In the current trial, 5,000 badgers will be killed — a number expected to be too small to have a significant impact on bovine TB. Vaccination, by contrast, is effective only in uninfected animals and is estimated to cost UK£620 per badger annually. BBC News/The Guardian