Evaluation of Take and Safety of a Smallpox Vaccine in Healthy Young Adults

Inclusion Criteria: * Aged 18 to 25 years on the day of screening * Informed consent form signed * Able to attend all scheduled visits and to comply with all trial procedures * For a woman, inability to bear a child or negative serum pregnancy test performed at screening (Visit 01) * Subject entitled to national social security * Subject registered in the French file of healthy volunteers in clinical trials * For a woman of child-bearing potential: use of an effective method of contraception (hormonal or barrier method) from at least 3 months prior to screening to 3 months following trial vaccination * For a woman, inability to bear a child or negative urine pregnancy test. Exclusion Criteria: * Previous smallpox vaccination confirmed by vaccination record or typical scar * Participation in another trial in the 3 months before or during the trial period * Acute intercurrent or chronic illness during the trial * Breast-feeding * Allergy or sensitivity to any known components of vaccinia immune globulin or previous reaction to immunoglobulins or trial vaccine * Congenital or acquired immunodeficiency or immunosuppressive therapy or any treatment including corticosteroids * Treatment with antiviral drugs within 1 month before vaccination * History of organ or bone marrow transplant or skin disorders * Personal or family history of autoimmune disease or cardiac disease, including cardiac risk factors * History or current central nervous system disease * Ongoing acute infectious disease * Blood or blood-derived products received in the past 6 months * Any vaccination with a live-attenuated vaccine within the 60 days or other vaccines within 40 days preceding the trial vaccination * Vaccination planned in the 8 weeks following the trial vaccination * Planned or foreseeable close contact after vaccination with infants less than 12 months, or with immuno-suppressed persons, pregnant and/or lactating woman, or practice of contact or water sports after vaccination before the crust separates * Skin wound near the vaccination site * Apparent lack of personal hygiene * Subject deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized without his/her consent * HIV, hepatitis B or hepatitis C seropositivity (screening tests) * Abnormal lab values for hematological parameters or cardiac enzyme (screening tests) * Feverish illness (oral temperature \>=37.5°C, rectal equivalent temperature \>=38.0°C) on the day of vaccination.