The main advantages
associated with plants include the low cost of agricultural biomass
production, elimination of downstream processing requirements for
vaccines expressed in edible plant tissues, post-translational modification
and production of correctly folded and assembled multimeric
proteins, low risk of contamination with pathogens and endotoxins
such as those occurring in mammalian and bacterial systems, and the
avoidance of ethical problems associated with transgenic animals and
animal materials.