A major trial of a new vaccine to fight tuberculosis has ended in failure after researchers discovered it did not provide protection to infants exposed to the bacteria.

The trial is significant because the current vaccine, Bacillus Calmette-Guerin (BCG) is only partially effective against the bacteria. While the new vaccine, MVA85A, showed some boosting of the immune system in adults, it produced no reaction in infants who had been given BCG.

The scientists had hoped the new vaccine could be a booster that would fill in the holes left by BCG.

The trial, held in South Africa, showed a success rate of only 17% for the vaccine. The scientists conducting the study called the percentage “statistically non-significant.” A non-profit group named AERAS, founded with the sole purpose of finding vaccines to eradicate tuberculosis, funded the research.

“Because of the urgency to control the global TB epidemic, and despite these results, we remain steadfast in our belief that an improved TB vaccine will be developed,” Dr. Tom Evans, CEO of AERAS, stated in a press release.

The World Health Organization considers tuberculosis a global health problem with an estimated 8.7 million cases a year leading to 1.4 million deaths.