NEEDHAM, Mass.--(BUSINESS WIRE)--AVANT Immunotherapeutics, Inc. (Nasdaq: AVAN) announced today the initiation of enrollment in a randomized, placebo-controlled, double-blind Phase 2 study of its typhoid fever vaccine candidate, Ty800, in approximately 180 healthy adult volunteers. The Phase 2 study is an out-patient, dose-ranging clinical trial that will evaluate two dose levels of the single-dose, oral Ty800 vaccine and will follow each subject for six months post-vaccination. The objectives of this Phase 2 study are to determine the optimal dose of Ty800 for further development based on the safety, reactogenicity, and immunogenicity of the vaccine. The study is being conducted by Accelovance Inc. of Rockville, MD at five clinical sites across the United States.