Subjects will be monitored in the clinic for a period of at least 30 minutes following vaccination for the occurrence of adverse events including local injection site reactions and systemic responses. For 7 days following vaccination and beginning the day of vaccination, subjects will maintain a symptom diary for daily recording of injection-site reactions as well as generalized systemic reactions including measurement of body temperature. Clinic staff will contact the subjects by telephone 2 days post vaccination (Day 3) to check for adverse events and to answer any questions related to collection of symptom diary information. Subjects will return to the clinic 7 days following vaccination (Day 8) for safety evaluation that will include a review of diary card information. A subset of subjects will additionally return to the clinic 10-14 days following vaccination (Days 11-15) to provide a blood sample for evaluation of cell-mediated immune (CMI) responses. All subjects will return to the clinic 21 days following injection (Day 22) for a safety evaluation and to provide a blood sample for measurement of humoral immunological parameters. A final safety evaluation (telephone contact) will occur at approximately 6 months following vaccination (Day 181).