Tuberculosis is a growing problem, especially in areas like Africa, which has been hit hard by HIV. And while most people infected with TB don't get sick because the immune system keeps it in check, those with HIV/AIDS are highly susceptible to the active form of the disease.
Compounding the problem is that some strains of TB have become drug-resistant. And Bacille Calmette-Guérin, the only vaccine currently in use, doesn't consistently protect against TB. Clearly, some new ideas are needed. Cue the scientists at the Howard Hughes Medical Institute, Albert Einstein College of Medicine and Colorado State University, who think they have found a potential TB vaccine.
The new vaccine was created with a strain of bacteria--minus a few genes--that makes it unavoidable to the patient's immune system. Once this first-line immune response gets to work, a more specific one is triggered that protects against future infections. For those interested in more specifics, the bacteria they used was M. smegmatis, and the gene they took out was ESX-3. They tried it in mice and found the vaccinated rodents stayed alive much longer than the unvaccinated ones (135 days vs. 54 days).
"Most notably," researcher William Jacobs says in a news release, "those vaccinated animals that survived for more than 200 days had livers that were completely clear of TB bacteria, and nobody has ever seen that before." That said, it is not known yet if this process would work in humans, but "it's certainly a significant step in efforts to create a better TB vaccine," Jacobs adds.