A major trial of a tuberculosis (TB) vaccine has ended in failure, marking a major setback in the fight against the disease, which cause 1.4 million deaths a year.
The latest vaccine, known as MVA85A, failed to protect babies who had already had the Bacillus Calmette-Guerin (BCG), the BBC reported.
BCG is only partially effective against the bacterium that causes TB, which is why several international teams are working on new vaccines.
The trial, in South Africa, involved 2,794 healthy children aged four to six months, half of whom received MVA85A and the rest a placebo.
They were followed up for an average of two years.
The researchers found 32 cases of TB in those who had received the vaccine compared with 39 in the placebo group.
This gave an effectiveness of 17 percent, which is so low as to be statistically non-significant.