Another infectious agent with a bioterror threat potential similar to anthrax, is the plague. Greffex has been constructing the GrePla candidate vaccine as a single target vaccine that can be combined with GreANX for immunization. In parallel, Greffex has assembled GreVAX-based vaccine, GreAnPla, that carries antigens for anthrax and plague on a single construct. This approach allows increased efficiency in manufacture and vaccination.