Tularemia, caused by the bacterium Francisella tularensis, is second to anthrax on the list of microbial pathogens that are dangerous potential bioterrorism agents. Tularemia was a major component of the former Soviet Union's bioterrorism armamentarium, and antibiotic-resistant strains of F. tularensis are in the hands of countries hostile to the United States. The tularemia organism is quite deadly, and is more easily weaponized for inhalation exposure than the anthrax bacillus. Moreover, little is known about how F. tularensis infects humans, mostly because the organism is so dangerous to work with and it usually only infects wild animals such as rabbits.
Our research initiatives involve elucidating fundamental molecular aspects of F. tularensis that allow it to cause human infection, as well as developing a new non-living vaccine that potentially can be used to protect our military and civilian populations against a bioterrorist attack. Using a special biosafety level 3 (BSL3) biocontainment facility built at UT Southwestern years ago, we developed a method to identify surface proteins of the organism that likely facilitate the bacterium's ability to cause infection, disease, and death. Among a number of discoveries that we have made, perhaps the most striking at this time includes our development of an acellular (non-living) vaccine formulation that has been shown to protect 100% of mice or rats against lethal disease.
The new outer membrane protein-based vaccine formulation has attracted the attention of the U.S. Army Medical Research Institute for Infectious Diseases (USAMRIID), as well as the U.S. Defense Threat Reduction Agency (DTRA). In collaboration with these military entities, we are planning on vaccinating monkeys at USAMRIID with our outer membrane protein-based vaccine formulation to test the safety and effectiveness of the vaccine in non-human primates as a prelude to human studies.