The children who got all the vaccines together had a lower immune response to the TB vaccine than those who got the TB vaccine separately, "Which implies that giving these two groups of vaccines together has a negative impact on the new TB vaccine."

Ota is the lead author of a paper describing the study.

He explains that although the measured tuberculosis immune response was lower when the TB vaccine was given with the other vaccines, it still may be enough to protect against the disease.

"We don't really know what the level that provides protection is. It might be that it is good enough, but we haven't reached that stage," Ota says in a video posted on the website of the journal Science Translational Medicine, which published his paper.

In the paper, the authors say that the lower immune response when the vaccines are given together is more likely a result of interference between adjuvants, which are additives used to boost the effectiveness of a vaccine.

There are benefits in giving all the vaccines together, including fewer clinic visits and higher vaccination rates, but for now, Ota says, the results of his study suggest that the new TB vaccine should be given separately.