Cell substrates are a key component of successful vaccine development and throughout the last several decades there has been a dramatic increase in the types of cells available for vaccine production. Nevertheless, there is a continued demand for new and innovative approaches for vaccine development and manufacturing. Recent developments involving cells of insect and plant origin are attracting considerable scientific interest. Here we review vaccine antigen production in plant-based systems as was presented by Dr. Vidadi Yusibov of Fraunhofer USA Center for Molecular Biotechnology at the LABS International Scientific Workshop on NEW CELLS FOR NEW VACCINES II that was held in Wilmington, Delaware on September 17-19, 2007. (C) 2008 The International Association for Biologicals.