Understanding our plant-based technology
Plants as mini protein factories.
All vaccines include a safe version of a disease antigen that will trigger an immune response and condition the body to defend itself against encounters with the disease. Traditionally, the antigen is produced by killing and splitting live viruses that were assembled and multiplied in primary cells, like chicken embryos or fertilized eggs, in bioreactors or in yeast, bacteria or cell cultures1.
Medicago's plant-derived vaccine development differs because it uses living plants as bioreactors to produce a non-infectious particle that mimics the target virus, without the use of any live viruses.
Our proprietary technology Proficia® uses N. benthamiana plants, which is the most widely used experimental host in plant virology, due mainly to the large number of viruses that can successfully infect it. Its weakened immune system, the result of natural genetic changes over millennia, means genetic material can be successfully hosted by the plant and not rejected2.
Medicago's proprietary plant-based platform Proficia® was named "Best New Vaccine Technology/Platform" at the World Vaccine Congress in 2019.
Ability to deliver research grade vaccines doses in 19 days and clinical grade in 6-8 weeks
Designed to accurately match the recommended target strains (for influenza)
Ability to produce both vaccines and antibodies with the same platform
Ease of scale-up, one plant or 10,000 plants require the same growth conditions
How it Works
Medicago researchers receive the antigenic viral gene sequence from global health organizations, synthesize it and introduce it into a plant-specific bacterial vector, that is then multiplied.
Plants are submerged in a solution containing the vector. A vacuum is applied, forcing air out of the intracellular spaces. The vacuum is released and the difference in pressure forces the vector in the solution into the leaves (vacuum infiltration).
The plant cellular machinery acts like mini-factories for 4-6 days and produces Virus-Like Particles (VLPs).
Plants are harvested to extract VLPs – the leaves are removed and blended into a solution, from which the vaccine material is isolated and extracted
The VLPs are purified to obtain the final material needed for the vaccine. Relevant sterility & quality tests are conducted.
Similar benefits, with potentially lower risks.
Virus-like particles (VLPs) represent an exciting approach to vaccine development. VLPs mimic the native structure of viruses, allowing them to be easily recognized by the immune system. However, they lack core genetic material which makes them non-infectious and unable to replicate. In other words, they induce an immune response similar to a natural infection but without the inconveniences associated with it. VLPs can also be engineered to have antigens attached for use in vaccines or other immunotherapies.
Infectious influenza viruswith a surface antigens, lipid membrane, internal proteins and genetic materials
- Vaccines Europe. https://www.vaccineseurope.eu/about-vaccines/key-facts-on-vaccines/how-are-vaccines-produced/
- Bally, J et al. Nature Plants. The extremophile Nicotiana benthamiana has traded viral defence for early vigour. Available at: https://www.nature.com/articles/nplants2015165 [Accessed March 2020]