A COVID Vaccine Made from Plants: Can Ending a Global Pandemic be ‘Eco-friendly’?

Retrieved from: Frederick, 2019. By: Markus Scholz

As we pass the one-year mark of COVID-19, everyone is becoming increasingly desperate to be freed from masks, social distancing, travel bans, depression, anxiety, and the never-ending hum of tragedies being reported on the news. Amidst the devastation, scientists have been working hard to develop one of the only tools that could end the pandemic- a vaccine. With the fastest development times in history, several companies like Pfizer and Moderna were able to roll out vaccines before the close of 2020; and now, everyone is waiting with bated breath for their turn at the jab. But is a needle the only thing that could save us? Could a simple pill made from plants be capable of delivering all of the necessary protection?

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Vaccine Jargon You Should Probably Know Before We Continue: just a few definitions of science-y words so that you can sound like an expert when you talk about this with your friends.

Everything is Plant-Based These Days… And your Vaccine Could be Too! Want to know how the heck you get a plant to protect you from a deadly disease? Find out here.

Why are they so good? There are many benefits to a plant-based approach- for you, for our planet, and for our economy.

Are They Realistic in these ‘Unprecedented’ Times? This is not sci-fi technology! A plant-based approach could be part of pandemic relief too.

Vaccine jargon you should probably know before we continue:

Antibodies: A protein produced by the immune system that can identify and neutralize a foreign object like a COVID virus

Antigens: A molecule found on the surface of a virus. If the immune system recognizes the antigen, it will trigger the release of antibodies that will neutralize the virus.

Virus-Like-Particle: molecules that look very similar to the real deal but are not capable of infecting. Kind of like a knock-off handbag. 


Everything is Plant-Based These Days… And your Vaccine Could be Too

For many readers, this may be the first time you’ve ever heard about a plant vaccine, but the idea has actually been buzzing around the science community for decades; and the rudimentary technology is not so different from your ‘run of the mill’ vaccine. Just like traditional inoculations, plant-based vaccines have the same goal: to get your body to produce specific antibodies that are capable of fighting off a specific disease. Let’s break this down a little more.

When you get exposed to a germ like COVID it has a unique set of antigens or ‘markers’ on its surface that make it different from other germs. If your body has never been exposed to the virus before, it will not recognize those antigens, and will not be able to produce the necessary antibodies to kill it. This means the virus can start multiplying and doing some damage. The goal of all vaccines, including plant-based ones, is to expose your body to a safe version of those antigens so that your immune system can make antibodies before you are exposed to the real virus. So, even if someone does sneeze on you, your body will be able to fight off their germs and you won’t get sick!

In any type of vaccine, you need a medium to grow the antigens. Traditionally, scientists turn to eggs or cultured bacteria cells. Can you guess where the antigens are cultured in plant vaccines? That’s right, plants! How do they get there? It’s actually a pretty simple process. To start, you will grow some bacteria that contains DNA that codes for the antigen. Then, you will get that bacteria to ‘infect’ your plant of choice (usually tobacco) and let that plant grow and do its thing. As it grows, it will start producing antigens; and after some time, you can collect, process, and purify your plant so that *poof* now you’ve got yourself a tablet or vial that is comparable to other vaccines.

*Note: not all plant vaccines are produced as pills. Some are still produced as injectable versions.

Why are they so good?

Retrieved from: ISAA, 2020

When I first heard about this concept, I was most excited by the idea that vaccines no longer had to be these scary needles that everyone said didn’t hurt, but that actually kind of did! ‘You’re telling me I could start taking pills instead of injections?!’ Yes! And the pill form doesn’t give you any ‘worse’ immunity than the jab. In fact, studies have demonstrated that consumed antigens are actually capable of providing both mucosal and systemic immunity.

The pill is not just good for squeamish patients. It’s also really good for our planet. Traditionally, the vaccine development process is very resource intensive. There’s a lot of high-tech equipment involved, scientists need to maintain a pristine level of sterility, the product itself needs to be stored just right, and a lot of waste is produced with the vials and needles. On the other hand, a plant vaccine really only needs three inputs: sunlight, fertilizer, and soil. It also has more lax storage procedures as there is less of a contamination concern and some plant-based approaches don’t require any pesky needles or vials. Best of all, the vaccine is much cheaper to produce than traditional ones. In fact, PlantForm was able to produce purified antibodies in tobacco that were 90% cheaper than ones grown in animal cell cultures.

Are they Realistic in these ‘Unprecedented Times’?

Photo by Anna Shvets on Pexels.com

At this point, you may be thinking, “This all sounds great, but plant vaccines seem like some crazy technology that can only be developed in the future.” I totally understand.

But did you know that a team of scientists in Canada is actually making significant advances in developing a plant-based vaccine for COVID-19? And while they may not be progressing quite as quickly as Moderna or Pfizer, they were able to develop ‘virus like particles’ in just 20 days after receiving DNA for the virus and in November 2020 announced they were moving on to Phase 2/3 clinical trials to test the efficacy of their drug.

Medicago’s Chief Medical Officer, Dr. Brian Ward estimated that his version of the vaccine could be ready by 2021 and that the company could produce as many as 1 million doses per month. Medicago has even reached an agreement with the Canadian government to supply the country with 76 million doses once they are approved. It’s not clear yet how exactly the government will be rolling out the vaccine to its citizens. But they have emphasized that the plant vaccine will play an important role in ensuring Canadians have long-term access to a domestically produced vaccine.

In the wake of Canada’s sub-par vaccine roll out, this is a bright spot that I hope brings some excitement and optimism to those who have otherwise been devoid of such feelings these last few months. Case numbers in Canada are devastatingly high, government action has become increasingly irregular and lacking, and it is starting to feel like we are living in a perpetual ground-hog day. The cold and unyielding winter has made many Canadians more depressed and isolated than ever before and we are all getting tired of buckling down. But now is not the time to rebel. We’ve lived through a year of this, we can soldier on for a few more months. Please, please, don’t stop wearing your masks, staying home and practising social distancing. If we stop caring now, we’ll only guarantee more suffering and more lockdowns. Stay safe and stay healthy.


Referenced material:

World Heath Organization. (n.d.). Plant derived vaccines. Retrieved 2020, August 28. https://www.who.int/biologicals/vaccines/plant_derived_vaccines/en/

Rybicki, E. P. (2014). Plant-based vaccines against viruses. Virology Journal, 11(205). https://doi.org/10.1186/s12985-014-0205-0

Laere, E., Ling, A. P. K., Wong, Y. P., Koh, R. Y., Lila, M. A. M., Husseing, S. (2016). Review Article: Plant-based vaccines: Production and challenges. Journal of Botany. http://dx.doi.org/10.1155/2016/4928637

Takeyama, N., Kiyono, H., Yuki, Y. (2015). Plant-based vaccines for animals and humans: recent advances in technology and clinical trials. PubMed, 3(5-6):139-154. https://doi.org/10.1177/2051013615613272

Lugadem A., A. Kalathil, S., Heald, J. L., Thanavala, Y. (2010). Transgenic plant-based oral vaccines. Immunological Investigations, 39(4-5): 468-482. https://doi.org/10.3109/08820131003622643

Rosales-Mendoza, S., Márques-Escobar, V. A., González-Ortega, O., Nieto-Gómez, R., Arévalo, Villalobos, J. I. (2020). What does plant-based vaccine technology offer to the fight against COVID-19. Vaccines, 8(2): 183. https://doi.org/10.3390/vaccines8020183

Medicago. (n.d.). Pipeline: Coronavirus. Retrieved 2020, August 31 from: https://www.medicago.com/en/pipeline/#coronavirus

Medicago. (2020). Safety, tolerability and immunogenicity of a Coronavirus-like particle COVID-19 vaccine in adults aged 18-55. ClinicalTrials. Retrieved from: https://clinicaltrials.gov/ct2/show/NCT04450004?draw=2

Rosales-Mendoza, S. (2020). Will plant-made biopharmaceuticals play a role in the fight against COVID-19. Expert Opinion on Biological Therapy, 20(6): 545-548. https://doi.org/10.1080/14712598.2020.1752177

iBio. (n.d.). iBio200: COVID-19 (VLP). Retrieved 2020, August 31 from: https://www.ibioinc.com/therapeutics-and-vaccines/ibio-200

Bridge, S. & Roumeliotis, I. (2021, January 12). Canada building facilities to make vaccines for COVID-19 and other viruses. CBC. Retrieved 2021, January 27 from: https://www.cbc.ca/news/health/vaccine-development-production-in-canada-1.5868398

Raymond, T. (2020, November 28). Quebec company making plant-based COVID-19 vaccine candidate here at home. CTVNews. Retrieved 2021, January 25 from: https://ottawa.ctvnews.ca/quebec-company-making-plant-based-covid-19-vaccine-candidate-here-at-home-1.5208573

ISAA. (2020, September 2). Experts Review Potential of Plant-Based Edible Vaccines. Retrieved 2021, January 28 from: https://www.isaaa.org/kc/cropbiotechupdate/article/default.asp?ID=18299

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