Canada has become the first country to authorize use of a plant-based COVID-19 vaccine.
Canadian regulators said Thursday Medicago’s two-dose vaccine can be given to adults ages 18 to 64, but said there’s too little data on the shots in people 65 and older.
The decision was based on a study of 24,000 adults that found the vaccine was 71 percent effective at preventing COVID-19 although that was before the omicron variant emerged. Side effects were mild, including fever and fatigue.
Medicago uses plants as living factories to grow virus-like particles, which mimic the spike protein that coats the coronavirus.
The particles are removed from the plants’ leaves and purified. Another ingredient, an immune-boosting chemical called an adjuvant that is made by British partner GlaxoSmithKline, is added to the shots.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
While numerous COVID-19 vaccines have been rolled out around the world, global health authorities are looking to additional candidates in hopes of increasing the worldwide supply.
Quebec City-based Medicago is developing plant-based vaccines against multiple other diseases, and the COVID-19 vaccine may help spur more interest in this new method of medical manufacturing.