4 September 2011 Last updated at 13:07 ET

Tuberculosis relative could be new vaccine

By James Gallagher
Health reporter, BBC News

Injecting modified bacteria related to those which cause tuberculosis could protect against the lung disease, US scientists say.

Experiments on mice showed the injections could completely eliminate tuberculosis bacteria in some cases, Nature Medicine reports.

The only TB vaccine - the BCG jab - is not very effective.

The research is in its early stages and the potential for a human vaccine is unknown, campaign group TB Alert says.

Tuberculosis is caused by Mycobacterium tuberculosis. It is one of the top 10 leading causes of death, according to the World Health Organization, killing 1.7 million people each year.

The BCG vaccine has variable results. It has been shown to be between 0% and 80% effective in different parts of the world.

“This is something we've dreamed about for years, to be able to get longer protection and bactericidal immunity.â€