Vaccines from Plants

I was browsing PubMed and stumbled upon a summary of the Third International Conference on Plant-Based Vaccines and Antibodies which just took place in June. I didn't manage to get access to the full article, but the fact that this has been around since 2005 piqued my interest. Sure, I'd expect that people are experimenting with vaccines in bacterial hosts, the same way any other protein is cranked out in E. coli. This was a little unexpected to me, so I dug deeper.

1. Santi, L. (September 2009). Plant derived veterinary vaccines. Veterinary Research Communcations. 33 Suppl 1:61-6.
   
   This article is pretty accessible to non-biologists, and gives a good introduction to this research area. While it's focus is on vaccines for non-human animals, the techniques can clearly be used for human pathogens. I think the concentration on veterinary diseases is mainly due to the amount of testing (read: cost) required to get FDA approval. Edible vaccines also have the benefit of reducing the reliance on antibiotics in non-human animals, and thus slowing the evolution of antibiotic resistance. Conceivably this approach could increase mutation in antigens targets by the vaccines, but I still think that it's a net benefit.
   
   
2. Tacket, C.O. (2009). Plant-Based Oral Vaccines: Results of Human Trials. Current Topics in Microbiology and Immunology. 332:103-17.
   
   This shows that for both bacterial and viral pathogens, this approach can work in humans. It also has the advantage of not having to involve needles nor chemical (or animal-derived) additives, and is much more stable. Seems to indicate to me that this economical approach will soon be the more common one.
   
   
3. Chebolu, S., and Daniell, H. (2009). Chloroplast-Derived Vaccine Antigens and Biopharmaceuticals: Expression, Folding, Assembly and Functionality. Current Topics in Microbiology and Immunology. 332:33-54.
   
   I think I'm just a sucker for an exotic host for protein expression. The authors tout the smaller genome and other features that make it a good expression host, But I can see how this could even further reduce problems with allergies and so forth: If you have the vaccine grown up in wheat, and someone has Celiac's disease, you can theoretically transplant the chloroplasts into corn without having to retransfect with a whole new mosaic virus. That and I also like how they say right in the abstract how this can be done "an environmentally friendly manner."

So by no means exhaustive, but it sounds promising to me. It may be a decade before we're chowing down on quinoa for our booster 'shot,' but by that time one plant could literally be a panacea of vaccines.