 Study was designed as a continuation of previously published research and targets subjects who were at risk of occupational exposure to F tularensis virus. Based on screening examinations; if a subject had a positive baseline titer 1:20 and gave no history of significant exposure to F tularensis or history of tularemia disease, had never received tularemia vaccination, and was at risk of exposure to F tularensis they could be enrolled in this protocol to receive vaccination. Subjects returned for follow-up exams on Days 1, 2, and 7; once between Days 12 and 16; and once between Days 28 and 35 post-vaccination. If titers; after blood samples on Days 28, 35 and 12 months showed 1:20 the vaccination could be repeated at Days 56-84. If the repeat titer remained 1:20, a booster vaccination could be administered. Subjects could be boosted 2 times with 1 year. If the titer measured 12 months after vaccination 30 days was 1:20 and the subject had no lingering AEs, the subjects participation was considered complete. 