The growing promise of plant-made biologics is highlighted by the success story 
of ZMapp™ as a potentially life-saving drug during the Ebola outbreak of 
2014-2016. Current plant expression platforms offer features beyond the 
traditional advantages of low cost, high scalability, increased safety, and 
eukaryotic protein modification. Novel transient expression vectors have been 
developed that allow the production of vaccines and therapeutics at 
unprecedented speed to control potential pandemics or bioterrorism attacks. 
Plant-host engineering provides a method for producing proteins with unique and 
uniform mammalian post-translational modifications, providing opportunities to 
develop biologics with increased efficacy relative to their mammalian 
cell-produced counterparts. Recent demonstrations that plant-made proteins can 
function as biocontrol agents of foodborne pathogens further exemplify the 
potential utility of plant-based protein production. However, resolving the 
technical and regulatory challenges of commercial-scale production, garnering 
acceptance from large pharmaceutical companies, and obtaining U.S. Food and Drug 
Administration approval for several major classes of biologics are essential 
steps to fulfilling the untapped potential of this technology.