The main virulence factor of Bacillus anthracis is a toxin that consists of three separate gene products; protective antigen (PA), lethal factor (LF) and edema factor (EF). In July Infection and Immunity, Brian Price and colleagues from Ohio State University showed that DNA-based immunization with a plasmid encoding the LF or PA protein provides complete protection against anthrax lethal toxin.

Price et al. used a gene gun to inoculate mice with either a vector plasmid encoding a fragment of PA or LF, or a combination of the two vectors. When the mice were injected with lethal doses of anthrax toxin two weeks later, all immunized mice survived whereas all non-immunized mice died. In addition, co-immunization was seen to be synergistic (Infect Immun 2001, 69:4509-4515).

These results suggest that it is feasible to use a DNA-based immunization strategy against anthrax and any future anthrax vaccine should consider...