Japan’s Astellas, a pharmaceutical company, is carrying out clinical trials for MucoRice-CTB vaccine, which protects against cholera and enterotoxigenic E. coli. Here’s the interesting point: it’s produced in transgenic rice plants.
Antisense genes specific rice storage proteins is introduced to switch the normal carbohydrate for the vaccine antigens. The matured rice is polished and powdered to release the drug substance.
Some good points: it is stable at room temperature, easy to produce in bulk, does not need to be refrigerated, typically cheaper, and will be orally-administered, which provides mucosal immunity in addition to systemic immunity.
Currently, the more commonly used cholera vaccines are in oral form, often marketed as Dukoral and Shanchol. There is an injectable form but is rarely in use.
This MucoRice-CTB vaccine is developed by researchers at the International Research Development Centre for Mucosal Vaccines (IMSUT) in Japan. Though transgenic plants has been a way to produce cheaper recombinant protein products for years, there are many difficulties like growing conditions. Astellas’ decision to license MucoRice-CTB vaccine signifies that there’s commercial prospect of transgenic plant production of vaccines.
Here’s hoping the trials succeed and the vaccine become more widely available to those who need them, especially in countries where cholera is endemic.
Talylor, P., 2016. BioPharma. [Online]
Available at: http://www.biopharma-reporter.com/Bio-Developments/Astellas-to-develop-rice-based-oral-cholera-vaccine
[Accessed 7 August 2016].