Safety and Immunogenicity Study of Venezuelan Equine Encephalomyelitis (VEE) Vaccine as Booster Vaccine in Adults

Inclusion Criteria: * Be 18 to 65 years old at time of consent * Have received VEE TC-83 vaccine * Have VEE plaque reduction neutralization 80% titers (PRNT80) \<1:20 * If female of childbearing potential, must agree to have a urine pregnancy test on the same day before each vaccination administration. (Exception: documented hysterectomy or \>3 years of menopause). The results must be negative. Females just agree not to become pregnant for 3 months after receipt of the last study treatment (vaccination). * Be considered at risk for exposure to VEE virus and who have submitted a Request for IND Vaccines for VDD vaccine. * Sign and date the approved informed consent document and HIPAA Authorization. * Have in their charts: * medical history (including concomitant medications) within 60 days of planned first administration of vaccine * physical examination and laboratory tests within 1 year * previous chest radiograph results and electrocardiogram * Be medically cleared for participation by an investigator (Examinations and/or tests may be repeated at the discretion of the PI). * Be willing to return for all follow-up visits. * Agree to report any adverse events (AEs) that may or may not be associated with administration of the vaccine for at least 28 days after administration and agree to report all serious adverse events (for example, resulting in hospitalization) for the duration of the subject's participation in the study. * Agree to defer blood donation for 1 year after re…