The purpose of this study is to evaluate the safety and immunogenicity of AERAS-422 in healthy, BCG-naïve adults.

This is a Phase I, randomized, controlled, double-blind, dose-escalation study of AERAS-422. This study will be conducted in 24 HIV-negative, healthy adults who are BCG-naïve and negative for prior exposure to Mtb at enrollment. The study will be conducted at one or more clinical research sites in the United States.

AERAS-422 will be administered on Study Day 0 as a single 0.1 mL intradermal (ID) injection containing either >= 10^5 to <10^6 CFU (low-dose) or >=10^6 CFU (high-dose). BCG Tice® will be used as an active control for AERAS-422 and will be administered as a single 0.1 mL ID injection containing 1-8 x 10^5 CFU on Study Day 0.

Inclusion Criteria:

-≥18 years and ≤45 years of age on randomization day

• Has general good health, confirmed by medical history and physical examination
• Has a screening body mass index (BMI) ≥19 and <33
• Females physically capable of pregnancy (not sterilized and still menstruating or within 1 year of the last menses if menopausal) in sexual relationships with men must use acceptable method of avoiding pregnancy from 28 days prior to randomization through the end of the study.
• Acceptable methods of avoiding pregnancy -Females physically capable of pregnancy must have:
• Negative urine pregnancy test within 21 days prior to randomization AND within 24 hours prior to Study Day 0 vaccination
• Ability to complete all protocol study visits and be reachable by telephone
• Provided written informed consent prior to screening evaluations
• Completed simultaneous enrollment in the Aeras Vaccine Registry protocol

Exclusion Criteria:

• Acute illness on randomization day
• Oral temperature >=37.5 degrees C on randomization day
• Abnormal laboratory values from blood collected within 21 days prior to randomization as follows:
• Positive test for hepatitis B core antibody or hepatitis C antibody
• Positive test for HIV
• Positive urine test for opiates, cocaine, or amphetamines
• Positive QuantiFERON®-TB Gold test
• History of treatment for active or latent tuberculosis infection
• Other evidence of active or latent tuberculosis, in the opinion of the investigator
• Tuberculin skin test (TST) within 90 days prior to randomization
• History or evidence of allergic disease or reaction that in the opinion of the investigator is likely to be exacerbated by any component of AERAS-422 or BCG Tice
• History or evidence of autoimmune disease, immunosuppression, or immunodeficiency, in the opinion of the investigator
• History or evidence of cheloid formation, axillary or cervical lymphadenopathy, or other dermatologic or anatomic findings that, in the opinion of the investigator, may interfere with the assessment of injection site reactions
• History or evidence of any other acute or chronic disease or condition that, in the opinion of the investigator, may compromise the safety of the subject or interfere with the evaluation of the vaccine safety or immunogenicity
• Medical, psychiatric, occupational, or substance abuse problems that, in the opinion of the investigator, will make it unlikely the subject will comply with the protocol
• Inability to discontinue daily prescription medications (except contraceptives) during the study.
• Received immunosuppressive medication within 45 days prior to randomization (inhaled and topical corticosteroids are permitted)
• Received investigational drugs or vaccine products within 182 days prior to randomization, or planned participation in any other investigational study during the study
• Received investigational Mtb vaccine at any time prior to randomization
• Received vaccination or immunotherapy with a BCG product at any time prior to randomization
• Received immunoglobulin or blood products within 45 days prior to randomization
• Received inactivated influenza vaccine within 14 days prior to randomization or any other standard vaccine within 45 days prior to randomization.
• Received systemic antibiotics within 14 days prior to randomization