On the commission of the Swedish Rescue Service Agency (SRV), FOI has investigated the antibody response in anthrax vaccinated SRV personnel. The antibody responses were investigated with ELISA. The antigen used in ELISA, Protective Antigen (rPA), was purified from a recombinant strain of Bacillus subtilis expressing rPA. Of a total of 44 investigated individuals, who had been vaccinated three times, 13 persons (30 %) showed significantly increased levels of antibodies. In contrast, in another group consisting of three individuals, who had received four vaccinations, all showed significant inreased levels of antibodies. The results suggest that the SRV vaccinated individuals need a revaccination before deployment to regions where exposures to anthrax could be suspected.