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Plant Based Vaccines

Vaccines have been a part of our lives from when we were babies. In Western countries everyone starts a regime of vaccinations weeks after birth that continues through school and beyond. In some jobs vaccines are a requirement, such as in the military. But now, with the global pandemic of covid, everyone is getting vaccinated, everywhere in the world and all at the same time. Vaccines are not animal friendly. They can involve animal based ingredients and, in many countries, all medicines, including vaccines, must be tested on animals before they can be used on people.


A Brief History of Vaccines

The first vaccine in Western medicine was the smallpox vaccine. In 1796 a doctor, Edward Jenner, found that injecting people with the fluid from cowpox pustules stimulates the immune system to develop antibodies against the virus. If the person came into contact with the smallpox virus after this their immune system treated it the same as the cowpox virus and killed it, protecting the person. Many consider this the first vaccine, however there is evidence that the Chinese had been using a similar technique as early as 1000 CE. It was also practiced in Africa and Turkey as well, before it spread to Europe and the Americas.


How Vaccines Are Normally Made

In the modern age, egg-based methods remain the most common practice used for commercial production of vaccines. It is easy to create a cheap and fast vaccine factory with the use of chicken eggs. However, the technology cannot be used for the COVID-19 pandemic because of the long production time in initially developing the vaccine and, most importantly, the fact that SARS-CoV-2 does not replicate in hens’ egg cells. Instead, many vaccine developers are using advanced platforms, such as DNA, RNA, protein subunits, inactivated viruses and virus-like particles (VLP).


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Soon our vaccines will be made here, not in test tubes

This has progressed into researchers having developed a plant-based COVID-19 vaccine that has been shown to produce a strong antibody response. The vaccine uses plants to create virus-like particles (VLPs), which are non-infectious and do not harm the plant. Phase 3 clinical trials have already started and the vaccine maker hopes the vaccine will be available in the U.S. and Canada soon. Like other COVID-19 vaccines, the plant-based option would be two-doses, 21 days apart and some of these vaccines have shown that subjects developed a strong antibody response after receiving the jab - “about 10 times higher than those seen in people recovering from natural disease,” Brian Ward, MD, Medicago’s chief medical officer involved in the trials has said.


“And those antibody [measurements] are higher than almost all of the other vaccines that have been reported to date.”

Brian Ward MD


These new vaccines are effectively grown in greenhouses. The scientists begin by isolating and then finding a way to reproduce the viral antigen, the molecule that stimulates an immune response. With Medicago’s vaccine, plants produce this antigen. The plant produces non-infectious the virus-like particles (VLPs), which the plant will do when a little bit of DNA is inserted into the plant cell to produce proteins.


“It's very similar to what AstraZeneca and the Johnson & Johnson vaccines do, except they do it in the human body,” Ward says. “They use adenovirus to deliver a little tiny piece of DNA into our muscle cells, and then our muscle cells produce the [SARS-COV-2] spike protein.”


With the plant-based vaccines, once the DNA is injected into the plant cell, the spike proteins move to the surface where they form little VLPs. They don't contain any genetic information, so they can't replicate and they’re non-infectious.


“We purify those virus-like particles (VLPs), and we inject it into your muscle with…something that helps to stimulate the immune response,” Ward stated.


These VLPs are basically an empty shell of the COVID-19 virus, they look like covid, but there's nothing on the inside. This means that your immune system will be exposed to more parts of the virus, not just the spike protein as is the case with the mRNA, producing a more rounded immune response that could give more protection against variants.


There are some clear benefits to developing plant-based vaccines. They are cheap to develop and plant-based vaccines are also faster to produce than other traditional vaccines. Medicago has also developed a plant-based flu vaccine which is currently being reviewed by Health Canada. The company says it takes five to six weeks to produce this new vaccine compared to the five to six months it takes when using egg-based production.


Will These Be The First Vegan Vaccines?

Although these vaccines will not use any animal derived ingredients or components they will still need the legally required testing for each country in which they are to be used and, in almost every case, this means animals testing. There are many different methods for testing drugs that do not involve the use of animals, but, like makeup testing, it takes a long time for the technology to become trusted and accepted. For more information about animal testing check out our posts Covid Vaccines and Animal Testing and Do We Really Need To Test On Animals.


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