Of course, there is no ethical way to put the hypothesis of its efficacy to the test. The primate data, however, would strongly indicate that the vaccine would have a positive impact in humans, and in this case, the primate model looks pretty solid.
I realize that you may be against the vaccine for any number of reasons, but to say flat out that it has no effectiveness against inhalation anthrax would be incorrect. Efficacy against inhalation anthrax in humans has not been proved or disproved.