Transgenic plants present enormous potential as one of the most cost-effective and safe systems for large-scale production of vaccines and other therapeutic proteins. Heat-stable plant-made (edible) vaccines are inexpensive to produce, can be administered orally and could be utilized to enhance vaccine coverage in children, particularly in developing countries. A selective advantage of plant-made vaccines is that the plant tissue they reside in can deliver the antigen to the mucosal immune system and at the same time prevent the antigen from degradation as it passes through the gut. Plant virus vectors have been designed to carry vaccine epitopes as well as full proteins safely and effectively. Here we discuss the current status of plant derived expression vectors used as biopharmaceutical production platforms, from proof-of-concept to the clinical trial stages and onwards to commercialization.