Tuberculosis vaccine hopes fade
4 February 2013 Last updated at 17:47 GMT
A major trial of a new booster vaccine has ended in failure, marking a major setback in the fight against tuberculosis (TB).
It was the first big study in infants since the Bacillus Calmette-Guerin (BCG) vaccine was introduced in 1921.
BCG is only partially effective against the bacterium that causes TB, which is why several international teams are working on new vaccines.
Prof Helen McShane, from the University of Oxford, who developed the vaccine, said that the trial provided valuable information despite the setback.