Phase I STEBVax in Healthy Adults

This study is a Phase I study of the safety and immunogenicity of recombinant Staphylococcal Enterotoxin B vaccine (STEBVax) in healthy adults. STEBVax is a recombinant mutated form of staphylococcal enterotoxin B (SEB) containing three point mutations that disrupt the interaction of the toxin with human major histocompatibility complex (MHC) class II receptors and render the protein non-toxic while retaining most of the immunogenicity. The primary intended result of this program is the development of a hyperimmune serum for treatment of toxic shock syndrome (TSS) originating from nosocomial, environmental or potential bioterrorist events. An additional long-term goal is the development of a multivalent vaccine and immunotherapeutic for treating or preventing diseases caused by Staphylococcus (S.) aureus. The long-range goal is to develop a vaccine that will protect against a broad range of staphylococcal superantigens. The primary objective is to evaluate and assess the safety of parenterally administered STEBVax vaccine in healthy adult subjects over a range of doses from 0.01 to 20 mcg by intramuscular injection. The secondary objectives are to determine the immunogenicity of STEBVax vaccine over a range of doses as determined by the rate and titer of seroconversion with serum anti-S. aureus enterotoxin B IgG antibodies measured by enzyme-linked-immunosorbent serologic assay (ELISA). Participants will include 28 healthy adult subjects from the University of Maryland Baltimore community. Subjects will receive a dose of STEBVax in Alhydrogel adjuvant at one of the following doses: 0.01, 0.1, 0.5, 2.5, 10 or 20 mcg or 2 doses of 20 mcg given 21 days apart. STEBVax will be administered as a single 0.5 mL intramuscular injection. Subjects will be followed for safety, reactogenicity, and immune response after vaccination. Subjects will be observed in the clinic for at least 8 hours after vaccination and remain in the Baltimore-Washington metropolitan area for 7 days after vaccination.