The future of vaccines may resemble, an edible vaccine, eating a salad, more than receiving an injection in the arm. Scientists at the University of California, Riverside are investigating the feasibility of transforming edible plants such as lettuce into mRNA vaccine factories.
COVID-19 vaccines employ mRNA or messenger RNA technology, which teaches our cells to recognize and defend against infectious diseases.
mRNA vaccines must be kept cold
One of the challenges with this new technology is that it must be kept cold during transport and storage to maintain its stability. If this new project is successful, edible plant-based mRNA vaccines that can be stored at room temperature will be able to overcome this obstacle.
The project’s objectives, made possible by a $500,000 grant from the National Science Foundation, are threefold: demonstrating that DNA-containing mRNA vaccines can be successfully delivered to the portion of plant cells where it will replicate; demonstrating that the plants can produce enough mRNA to rival a traditional injection; and determining the optimal dosage.
The ideal plant would generate enough mRNA to immunize just one person
“The ideal plant would generate enough mRNA to immunize just one person, according to Juan Pablo Giraldo, an associate professor in the Department of Botany and Plant Sciences at UC Riverside who is leading the research in collaboration with scientists from UC San Diego and Carnegie Mellon.
Spinach and Lettuce as an edible vaccine
“We are currently testing this method with spinach and lettuce, and our long-term goal is for individuals to grow it in their own gardens,” Giraldo explained. Farmers could eventually cultivate entire fields with it.
Chloroplasts, which are organelles in plant cells that convert sunlight into energy the plant can use, are crucial to this process. “They are tiny, solar-powered factories that produce sugar and other molecules necessary for plant growth,” Giraldo explained. Additionally, they are an untapped source for producing desirable molecules, for developing this edible vaccine.
Giraldo has demonstrated that it is possible for chloroplasts to express genes that are not normally found in plants. This was accomplished by sending foreign genetic material into plant cells encased in a protective shell. Determining the optimal characteristics of these casings for delivery into plant cells is the laboratory’s specialty.
Gene delivery to plants
For this project, Giraldo collaborated with Nicole Steinmetz, a professor of nanoengineering at UC San Diego, to use nanotechnologies developed by her team to deliver genetic material to chloroplasts.
“Our concept is to repurpose naturally occurring nanoparticles, specifically plant viruses, for gene delivery to plants,” explained Steinmetz. “Some engineering is required to direct the nanoparticles to the chloroplasts and render them non-infectious to plants.”
For Giraldo, the opportunity to develop this concept using mRNA fulfills a lifelong ambition. “One of the reasons I began working in nanotechnology was to apply it to plants and develop innovative technological solutions. Not only for food but also for high-value products such as pharmaceuticals,” said Giraldo.
Additionally, Giraldo is a co-leader of a project that uses nanomaterials to deliver nitrogen, a fertilizer, directly to chloroplasts, where plants require it.
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Nitrogen is scarce in the environment, but it is essential for plant growth. The majority of farmers add nitrogen to the soil. Consequently, approximately half of it contaminates groundwater, causing algal blooms and interacting with other organisms. In addition, it generates nitrous oxide, another pollutant.
This alternative method would get nitrogen into the chloroplasts through the leaves and regulate its release, a significantly more efficient method of application that could aid farmers and improve the environment.
The National Science Foundation has awarded Giraldo and his colleagues $1,600,000 to develop this targeted nitrogen delivery system.
Giraldo stated, “I am very enthusiastic about all of this research.” I believe it could have a significant impact on people’s lives.
How does an edible vaccine work
An edible vaccine is a food, usually a plant, that has vitamins, proteins, or other nutrients that protect against disease. When a plant, fruit, or product made from a plant is eaten, it boosts the immune system.
On the other hand, edible vaccines are easy to make, clean, sanitise, and spread.Since they do not need expensive equipment to make, only good soil, the cost of growing vaccines is much lower.[3] Also, edible vaccines do not need sterilised production facilities or the expensive biosafety standards needed to grow certain pathogens for traditional vaccines.[1] They are also easier and cheaper to store because they do not have to be kept in the fridge.
