In this proposal, Protein Sciences Corporation proposes to develop a bivalent, recombinant protein based adenovirus vaccine to protect against serotypes 4 and 7, based on our proprietary platform technology of baculovirus expression vector system (BEVS) and insect cells. We propose the hexon protein as the target antigen as it is considered the primary target for neutralizing antibodies generated against adenovirus, and protection from adenovirus disease is associated with the presence of serotype specific serum neutralizing antibodies. The use of recombinant baculovirus to express foreign proteins in insect cells has been well characterized, and has matured into a commercial manufacturing technology. This technology will allow rapid incorporation of additional serotypes if the need arises. The fundamental high level objective of Phase I is to demonstrate the feasibility of expression and purification of the hexon proteins based on the BEVS and insect cell platform technology, and to provide preliminary stability assessment on the candidate product. The resulting proof-of-concept data should support the future objectives in Phase II for pilot scale process development, immunogenicity studies in small animals, toxicology study, and other preparation activities related to filing an Investigational New Drug (IND) application with the FDA for Phase I clinical trial.