If a bioterrorist attack is suspected, or after an exposure, prophylaxis with ciprofloxacin 500 mg twice a day or doxycyline 100 mg twice a day is recommended for the target population. Treatment duration should be 4 weeks, while the effects of simultaneous vaccination take effect [36] . Resistance to penicillin and tetracycline should be assumed until proved otherwise by susceptibility testing [20] .