New vaccine being developed for tuberculosis
Albert Einstein College of Medicine Professor William Jacobs has devised a new vaccine to fight the bacteria mycobacterium tuberculosis, more commonly known as the disease tuberculosis.
Tuberculosis is a both lethal and common bacterial infection that affects the lungs. It is transmitted through the air when an infected person coughs or sneezes. An infected person will exhibit classic symptoms such as blood-tinged sputum, a deep cough, fever, weight loss and night sweats.
Currently, there is an existing vaccine, bacile Calmette-Guerin (BCG), that provides protection against childhood forms of tuberculosis but is mostly ineffective against the adult form of the disease. The adult disease is increasingly spreading and becoming more common.
Researchers from Albert Einstein, led by Jacobs, began attempting to create a vaccine based on the belief that the key to preventing tuberculosis is to understand more completely the bacteria that causes it. Somehow mycobacterium tuberculosis currently circumvents the human immune systems, and researchers assumed that if they could discover how it does so, they could develop an effective vaccine.
The vaccine was tested in mice to discover how effective it is. Only one-fifth of mice showed resilience to the disease, so while the vaccine works, it still has to be improved before it can be used on humans.
"Most notably, 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,” Professor Jacobs said. “We don't even know yet if it will work in humans, but it's certainly a significant step in efforts to create a better TB vaccine."
Tuberculosis is responsible for 1.7 deaths every year around the world. Jacobs and his team were able to develop the vaccine by altering genes in the mouse bacteria. By deleting the set of genes called ESX-3 from the mouse bacterium and replacing them with ESX-3 genes of the human infectious agent, they were able to test the mice and still know how effective the vaccine would be in humans. After the gene alterations, the vaccinated mice were able to live much longer than the control mice. The vaccinated mice lived 135 days, whereas the control mice lived only 54 days.
A non-profit company called Aeras has licensed the technology being used to create the vaccine. Aeras is a development partnership that was created to fight TB. In the future, the technology being used to make the tuberculosis vaccine could be used to make a leprosy vaccine and eliminate other bacterial infections.