First plant-derived COVID-19 vaccine candidate from Canadian biotech Medicago enters human trials- Technology News, Firstpost

tech2 News StaffJul 17, 2020 13:58:57 IST

Canadian biopharmaceutical company Medicago started Phase I clinical trials for its plant-based COVID-19 vaccine candidate this week. The first doses were given to 180 healthy human volunteers. The company hopes 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 plant-derived vaccine candidate is now the first from Canada among the more than 20 experimental coronavirus vaccines being tested in humans.

Medicago’s Phase I clinical trial for the plant-derived vaccine is a randomised study in 180 healthy subjects including male and female volunteers between the ages of 18 and 55. The active compound in the vaccine, a “recombinant Coronavirus Virus-Like Particle (CoVLP),” will be tested in different doses alone, and with an adjuvant – an agent that boosts the immune response from a vaccine.

Plant-based vaccines have been a technology in the works for over 20 years. Image: European Vaccine Alliance

There are two points of difference between Medicago’s candidate and traditional vaccines. 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.

The structure and cross-sectional view of the novel coronavirus SARS-CoV-2. Image: Wikimedia

This bypasses the complexity and expense of using massive bioreactors and factories to make vaccines, which are essentially protein molecules that can be made by living systems if they are manipulated.

This plant-based manufacturing technology has cleared Phase III clinical trials for an influenza vaccine candidate, and pandemic Phase II clinical trials for a H1N1 pandemic vaccine candidate.

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, and be able to produce up to 1 billion doses of the COVID-19 vaccine annually.