Can Plant-Based Vaccines Speed Up Production?

Phase III clinical trials are to begin shortly on a COVID vaccine — and its radically faster production process — produced by a Canadian company.

Quebec-based Medicago says its method could produce as many as 10 million doses a month.

The company is recruiting 30,000 potential vaccine recipients in ten countries in Europe and North and South America for phase III clinical trials. 

Unlike traditional vaccine production, during which a vaccine manufacturer injects a live virus into chicken eggs to propagate, Medicago inserts a genetic sequence into soil bacteria, which are taken up by a tobacco-like plant. The resulting crops carry a protein that can be used to produce a vaccine and the process can be tweaked to match new virus strains. DARPA originally supported the research through a 2009 program dubbed Blue Angel to speed the development of new vaccines. 

The company is working with British pharmaceutical company GlaxoSmithKline, which is providing the COVID-19 pandemic adjuvant — essentially, the ingredient that triggers the immune system to respond more vigorously.

Dr. Brian Ward, a professor of medicine and microbiology at McGill University and a medical officer at Medicago, said, “If we are successful… and then we get a rapid fast-track in the U.S. authorization, we have the ability with our existing facilities to produce upwards of 80 million doses in the next twelve months,” then 160 million in the following year. He thinks that they should be able to contribute millions of doses by August.

Somewhat more remarkable is the short time span it took Medicago to develop a vaccine candidate. Ward said that once you have the genetic information on the virus you wish to develop against, their method can produce a vaccine in five to six weeks, as opposed to months for traditional methods. It’s one reason Medicago was able to produce a vaccine candidate last March, many months before other contenders. 

But are plant-based vaccines as effective as the ones that have already achieved FDA approval? The phase III clinical trial will help answer that, but Ward says that there’s reason to be optimistic. “In our phase I and phase II studies, our vaccine is generating neutralizing antibodies that are as high or higher than anybody else's…So far, in the short term, neutralizing antibodies appear to be really important,” he says.

Last March, Medicago CEO Bruce Clark forecast that the vaccine wouldn’t clear regulatory hurdles until November 2021. But they were awarded fast-track designation on February 17. 

By the end of 2023, Ward said, Medicago will be able to make a billion doses per year.