A modified version of the BCG vaccine against tuberculosis could allow cattle around the world to be vaccinated against the disease for the first time. At present, the disease is controlled by slaughtering infected cattle and other animals thought to spread it, such as badgers, which has been a source of controversy.

The modified vaccine has been tested only in guinea pigs so far, but the team is confident it will work in cattle too. “We would expect it to work in cows,” says team leader Johnjoe McFadden at the University of Surrey, UK. Testing in large animals like cattle is expensive, he says, and the team hasn’t yet got the funding.

Vaccinating cattle with the standard BCG vaccine used in people – which contains a live bacterium – is banned in most countries. The reason is that the vaccine protects only about 70 per cent of cattle and a standard test can’t distinguish between cattle that have been vaccinated and those that are infected.

Get the full story at newscientist.com.