TB vaccine closer

Vaccination to control bovine tuberculosis could be a step closer with the development of a test which can distinguish between vaccinated and infected animals.

TB is on the increase in UK cattle and vaccination is under active consideration, says the Institute of Animal Health. This would involve using the same vaccination used to immunise humans against the disease, BCG. However, BCG-vaccinated cattle test positive using the tuberculin skintest. Before a bovine TB vaccination strategy can be implemented, amethod of distinguishing between vaccinated and infected animals has tobe established.  The diagnostic test developed relies on the information that immunecells of cattle previously infected with TB contain more of the proteingamma interferon than those vaccinated for TB. The test can provide same day, on farm diagnosis of TB and identify which are vaccinated andwhich are infected.