An anthrax vaccine with alhydrogel as the adjuvant is presented in a composition formulated by mixing rPA with colloidal alhydrogel (alum) adjuvant to produce the final product, comprising 200 μg/ml rPA bound to 0.26% alhydrogel in phosphate buffered saline (PBS), said formulation containing an optimal concentration of phosphate. Methods of using the vaccines to treat or prevent infections are also presented.
