Canadian biopharmaceutical company Medicago started Phase I clinical trials for plant-based COVID-19 vaccine this week. The first doses of vaccine were given to 180 healthy volunteers. The Medicago expects to start a combined Phase 2 and 3 trial by October this year, provided it gets approval to do so based on satisfactory data from its Phase 1 trial.
Medicago’s Phase I clinical trial for the plant-based Covid-19 vaccine is a randomised study in 180 healthy volunteers between the ages of 18 and 55. The active compound in the vaccine will be tested in different doses alone, and with an adjuvant. The active compound is a ”recombinant Coronavirus Virus-Like Particle (CoVLP),”
Medicago’s Vaccine Development Programs
Medicago is a leader in plant-based vaccine technology and they have already demonstrated their potential to be a first responder to pandemic situations with their work in quickly developing vaccine candidates for both H1N1 influenza and Ebola. Medicago’s first product, a seasonal influenza vaccine, is currently under review by Health Canada.
How does Medicago’s plant-based approach differentiate from traditional vaccine development?
The biotechnology company uses a plant-based platform to develop their vaccines. This approach uses living plants as bioreactors to produce non-infectious versions of viruses (called Virus-like Particles, or VLPs). Researchers use VLPs that mimic the architecture of a virus but are non-infectious. The VLPs present antigens to the individual’s immune system in a highly efficient manner, eliciting a protective and long-lasting immune response. However, they lack core genetic material which makes them non-infectious and unable to replicate.
Medicago successfully produced a VLP of the coronavirus in early March 2020, just 20 days after obtaining the SARS-CoV-2 (the virus causing the COVID-19 disease), as announced here.
The Medicago vaccine candidate against the novel coronavirus doesn’t use a weakened, inactivated form of the coronavirus, as traditional vaccines do. Instead, it uses a “Virus-Like Particle” that closely resembles the coronavirus, enough for the immune system to recognise it and produce antibodies to defend the body from infection. Since the virus-like particles lack the core genetic material that makes them infectious, they will not replicate or cause an infection, which is a risk factor with traditional vaccines
The second point of difference in Medicago’s vaccine candidate is the technology used to mass-produce the virus-like particles. For this, the company makes use of a proprietary technique that hacks into plant cells and encourages the cell’s machinery to produce the active component of a vaccine.
In the case of the COVID-19 vaccine candidate, Medicago is using the leaves of a plant from the tobacco family to produce the virus’ S-spike protein, one of the three spike proteins of the novel coronavirus.
When will Medicago’s plant based COVID-19 vaccine be available?
Before launching a vaccine, it is essential to test its safety and efficacy during clinical trials. Medicago expects to be able to manufacture approximately 100 million doses by the end of 2021. By 2024, the company expects to expand operations to a new commercial facility in Quebec City, Canada and be able to produce up to 1 billion doses of the COVID-19 vaccine annually. In 2012, Medicago produced 10 million research-grade doses of a H1N1 pandemic vaccine in one month for DARPA’s Blue Angel program. This production yield has helped to inform their estimates.