McShane and her co-authors wrote that the vaccine could potentially protect adolescents or adults against TB since their immune systems work differently from those of infants. The shot is also currently being tested in people with HIV.
"If this vaccine is effective in adults, that would be hugely valuable because the majority of TB disease and deaths are among adults," said Richard White, an infectious diseases expert at the London School of Hygiene and Tropical Medicine. "But no one knows the answer to that right now."
"A vaccine is likely to be a cost-effective way of preventing TB," he said, comparing the $650 million that has been invested into vaccine development in the past decade versus the more than $4 billion it currently costs to control the disease every year, according to the World Health Organization.
White also warned the world couldn't afford to ignore the spike in TB and its drug-resistant forms. "There are certain boroughs of London that have higher rates of TB than parts of Malawi," he said. "TB is such a big problem that we really need to throw the book at it."