The study of twenty-eight hundred South African infants who had previously received the BCG vaccination found that the MVA85A vaccination — which is designed to build on the limited immunity produced by BCG — did not help prevent new infections or stop the progression of existing ones. While Aeras has six TB vaccines in clinical trials and a larger number in laboratory development, the study results are unlikely to stop work on the other candidate vaccines, the Washington Post reports. "We're disappointed that the trial did not have a positive outcome," Aeras interim CEO Tom Evans told the Post. "We can't necessarily say this kind of vaccine is not going to be efficacious in another population."
Funding for the trial was provided by Aeras, the Wellcome Trust, and the Oxford-Emergent Tuberculosis Consortium, a joint venture between Emergent BioSolutions and the University of Oxford, which originally developed the vaccine. Aeras, which has offices in Rockville, Maryland, and Cape Town, South Africa, received a five-year, $220 million grant from the Bill & Melinda Gates Foundation last March to accelerate the development of safe, effective TB vaccines.
"Researchers are conducting further analyses of the samples gathered in this trial for potential insights into correlates of risk of TB disease — biological markers that predict risk of developing TB disease after being infected with the pathogen," said Evans. "Only by doing trials such as this one can we start to tease out what protects some humans from TB and why only 10 percent of those who are infected go on to develop disease."