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A vaccine of the future against COVID-19


Dr. Denis Leclerc, professor in the Faculty of Medicine at Laval University and researcher at Quebec City’s CHU Research Centre (Image source: Marc Robitaille)

There’s excitement in the air at the laboratory of Dr. Denis Leclerc, a professor in the Faculty of Medicine at Laval University and a researcher at Quebec City’s CHU Research Centre. Dr. Leclerc and his team of five are hard at work developing a vaccine that may be effective not only against the virus responsible for COVID-19, but also against several other related types of infections. The researchers are building their vaccine out of two components, one of which is based on the unusual powers of a virus that attacks papaya trees.

A proven technology

“We’re working on the vaccine of the future”, says Dr. Leclerc. He has received over $700,000 in funding from the Government of Canada’s Canadian Institutes of Health Research to develop his planned vaccine, which will apply a technology that he and his team have been perfecting for several years. This technology involves using a plant virus—papaya mosaic virus (PapMV)—to enhance vaccines for human beings. . Dr. Leclerc explains how this technology works: “The proteins in the PapMV virus are harmless to human beings, but our systems nevertheless identify them as foreign. This triggers a very strong, built-in immune reaction to protect us.”

In addition to being fast and powerful, this immune response has the advantage of operating on two different levels. “First,” says Dr. Leclerc, “it triggers the production of antibodies. Second, it stimulates the production of specialized cells that recognize infected cells and attempt to destroy them.”

Dr. Leclerc and his team are taking advantage of these surprising properties of PapMV to develop more effective vaccines. Using nanoparticle technology, the researchers have stabilized some of the proteins in PapMV so that it can serve as a “platform” to deliver vaccines into the human body. The team has already tested this approach against the H1N1 strain of the seasonal flu virus.

Protecting against all strains of the virus

Dr. Leclerc explains how he will be applying this technology to COVID-19. “We want to combine our PapMV virus with an antigen for the COVID-19 virus to create a very effective, very safe vaccine. The idea is to trick the body so that when it comes in contact with pieces of the virus that causes COVID-19, it will have the same highly effective immune response as it does to PapMV.”

One important detail is that the antigens that the researchers will be using to manufacture the second component of their proposed vaccine will not be taken from people who have coronavirus, but will instead be produced in the laboratory. Says Dr. Leclerc, “I have studied the structure of the SARS-CoV-2 virus that causes COVID-19, and I have selected the parts of this virus that are most likely to be involved in related types of infections as well. This strategy will let us develop a vaccine that protects not only against the virus that is causing the current pandemic but also, more broadly, against strains of this virus that have undergone mutations.”

If all goes well, the model vaccine that Leclerc and his team are developing will go into preclinical trials by this fall. As he relates, “The four researchers with whom I’m working are highly motivated, and all of us are working as hard as possible.” But he also cites a reality of life in research laboratories that cannot be ignored. “My colleagues also have families. They have children. They’re coping with the same kinds of demands that the pandemic is placing on all of us, so of course they’re experiencing their share of anxiety and fatigue. I want to accommodate them however I can.”

Longstanding support

For NSERC, it is no surprise to see Denis Leclerc’s research receiving such large-scale federal funding in this time of crisis. The value of his ideas has been recognized for many years now. He has been receiving recurring annual funding from NSERC since 2000 for his work on using plant viruses for human vaccination and since 2008 for his research on PapMV in particular. The peer review committees that make recommendations on awarding NSERC grants have long recognized his ideas and expertise. NSERC is therefore proud to support Dr. Leclerc and hopes that his research will help to improve health and quality of life for all Canadians.

This article has been translated and adapted with the permission of This link will take you to another Web site Université Laval.