BARDA Securing Anthrax Immunity For the Elderly

Inclusion Criteria

• Male or nonpregnant females, 66 years of age or older at the time of randomization for the elderly population, or 18 through 50 years of age at the time of randomization for the younger population.
• Females who are of childbearing potential and are sexually active with a male partner must agree to use an acceptable method of birth control from Screening to Day 64 and must have used a reliable birth control method for at least 2 months prior to Screening.
• A female of childbearing potential is defined as post onset menarche and pre-menopausal female capable of becoming pregnant. This does not include females who meet any of the following conditions: menopausal >2 years, tubal ligation >1 year, bilateral salpingo-oophorectomy, or hysterectomy.
• Adequate contraception is defined as a contraceptive method with a failure rate of less than 1% per year when used consistently and correctly and when applicable, in accordance with the product label. Examples include: oral contraceptives, either combined or progestogen alone; injectable progestogen; implants of etenogestrel or levonorgestrel; estrogenic vaginal ring; percutaneous contraceptive patches; intrauterine device or intrauterine system; male partner sterilization at least 6 months prior to the female subject's Screening Visit, and this male is the sole partner for that subject (the information on the male partner's sterility can come from the site personnel's review of the subject's medical records or interview with the subject on her medical history); male condom combined with a vaginal spermicide (foam, gel, film, cream, or suppository); male condom combined with a female diaphragm, either with or without a vaginal spermicide (foam, gel, film, cream, or suppository).
• Able to provide written informed consent prior to initiation of any study procedures. As part of the consent process, subjects must be able to demonstrate understanding by passing the "Assessment of Understanding Questionnaire" within 2 attempts. Passing is defined as being able to answer all questions correctly.
• In relatively stable health based on site investigator's judgment, as determined by medical history, physical examination, and the following criteria:
• Stable health for age (defined as no new conditions per medical history, new medications in a different therapeutic class, or change in daily dose of existing prescription medications within the 45 days preceding Screening). Effective treatment (to resolution) of an acute infection (e.g., urinary tract infection, cellulitis, otitis, or bronchitis) with an antibiotic within 45 days preceding Screening will not be considered a deviation from this inclusion criterion as long as the antibiotic therapy was completed at least one week prior to Screening and no signs or symptoms of the infection have been present since the completion of treatment. Any prescription change that is due to change of health care provider or insurance company, or that is made for reasons that do not reflect a change in disease status (e.g., financial considerations), as long as within the same general class of medication, will not be considered a deviation from this inclusion criterion. Any change in prescription medication due to improvement of a disease outcome, as determined by the site investigator, will not be considered a deviation from this inclusion criterion.
• Subjects may be on chronic or as needed (prn) medications if, in the opinion of the site investigator, these pose no additional risk to subject safety or assessment of reactogenicity and immunogenicity and their use is not for management of a worsening of medical diagnosis or condition. Note: Topical, nasal, and inhaled medications (with the exception of steroids, as outlined in the subject exclusion criteria) and vitamins are permitted.
• Have a body mass index (BMI) less than 35.0 kg/m2 at Screening. (BMI will not be reassessed prior to subsequent vaccinations.)
• Have access