Evaluation of Safety, Immunogenicity, and Prevention of TB With AERAS-404 and BCG Revaccination in Healthy Adolescents

The H4 antigen is a fusion protein created from two Mtb antigens: antigen Ag85B and TB10.4. Ag85B is also referred to as α-antigen and is a 30-kDa mycolyl transferase protein. TB10.4 is one of three members of the very similar ESAT-6 group of proteins found in Mtb culture supernatants. TB10.4 induces broad immune responses in T cells isolated from TB subjects compared to BCG-vaccinated donors and unvaccinated donors. IC31 is a combination of a leucine-rich peptide named KLK \& a synthetic oligonucleotide named ODN1a. The optimal molar ratio of KLK to ODN1a in mice is 25:1. AERAS-404 \& saline placebo trial arms will be double-blinded since BCG causes a recognizable local injection site reaction, the BCG revaccination trial arm will be unblinded.

Saline

BCG SSI Vaccine is registered in South Africa for prevention of TB in children and adults. BCG, an attenuated, live culture of the Bacillus Calmette-Guérin, was originally attenuated between 1906 and 1919 by serial passage of an M. bovis strain. The manufacturer Statens Serum Institut (SSI) in Copenhagen, Denmark derives this vaccine from the Danish BCG strain 1331. BCG SSI is supplied by the manufacturer in amber 10-dose vials containing 0.75 mg lyophilized SSI BCG. The BCG revaccination trial arm will be unblinded (open label).