Tuberculosis is the deadliest infectious disease worldwide (prior to, and aside from COVID-19 infections). According to the World Health Organization, close to 10 million people worldwide are infected with tuberculosis and develop symptoms yearly. And 1.5 million people die from the disease each year. While tuberculosis infection occurs in all countries around the world, including approximately 8,000 infections per year in the United States, the disease disproportionately affects low and middle-income countries.
Mycobacterium tuberculosis is the species of bacteria that causes tuberculosis. The bacteria can spread easily from person-to-person as infected individuals can transmit the bacteria to others through coughing, talking, singing, and laughing which allows the bacteria to become aerosolized and enter the lungs of nearby people. While treatment for tuberculosis can be effective, treatment options are not readily available for all individuals. As such, many companies and researchers have sought to design and develop vaccines against the disease.
Some vaccines have shown great promise in the fight against tuberculosis. But, despite these advances, one issue that is critical for vaccine development is the ability for vaccines to remain stable and effective in hot environments. For example, many vaccines require cold refrigeration, and if the vaccine is removed from refrigeration for an extended period of time before it is administered, it becomes ineffective. Recently, researchers from the United States and Nigeria published their research on a development process that could make tuberculosis vaccines thermostable.
The process, known as lyophilization, is a technique where the contents of the vaccine are freeze-dried. (See the above embedded video for an excellent Labroots sponsored talk on the process of lyophilization.) The researchers tested the process of lyophilization on a tuberculosis vaccine candidate that had already reached successful Phase 2 clinical testing. The researchers reported that after lyophilization of the vaccine, it demonstrated 24 months of stability when stored at 5°C (41°F). Importantly, the vaccine maintained stability for 3 months when stored at 37°C (98.6°F). In other words, they found that the process of lyophilization allowed the tuberculosis vaccine to remain unrefrigerated for an extended period of time while also maintaining effectiveness.
The researchers, state that, “this study represents the first report on the successful lyophilization of a thermostable subunit vaccine candidate.” The researchers anticipate that future research will include clinical testing of the lyophilized vaccine and further scale-up to prepare for large-scale commercial manufacturing.
Sources: CDC; Morbidity and Mortality Weekly Report; WHO; Tuberculosis (journal); labroots; New England Journal of Medicine; News Medical Life Sciences; Frontiers