Toronto – Given the alternative, would you rather get vaccinated by taking a shot in your hand or eating a bowl of vegetables?

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Scientists at the University of California, Riverside (UCR) are currently studying whether they can turn edible plants like lettuce and spinach into mRNA vaccines people can develop themselves.

The research project has three goals: to show that DNA containing mRNA vaccines can be successfully integrated into plant cells; To demonstrate that plants can replicate enough mRNA to compete with current injection methods; and to determine the correct dosage.

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“Ideally, a single plant would produce enough mRNA to vaccinate a person,” said lead researcher and associate professor Juan Pablo Giraldo, from UCR’s Department of Botany and Plant Sciences. News release.

“We are testing this approach with spinach and lettuce and have long-term goals for people to grow it in their own gardens,” he said. “Farmers can eventually grow entire fields of it as well.”

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According to Giraldo, the key to producing mRNA vaccines in plants are the chloroplasts, which are small organelles in plant cells that are responsible for photosynthesis.

“They are small, solar-powered factories that produce the sugar and other molecules that allow the plant to grow,” Giraldo said. “They are also an untapped source for making desirable molecules.”

Previous laboratory work by Giraldo showed that chloroplasts can express genes that are not naturally part of the plant. This was achieved by sending foreign genetic material into plant cells inside a protective covering.

Similar research into an edible COVID-19 vaccine is also being conducted closer to home.

A team of scientists led by Alison McLean, an assistant professor in the University of Ottawa’s Department of Biology, has been working on alternative means of vaccination against the virus for more than a year.

His method involved the expression of viral antigens in edible plants, including lettuce and spinach, which people then ate. The vaccine has already begun trials under a partnership with Ottawa Hospital.

The mRNA technology used in some conventional COVID-19 vaccines works by using mRNA to provide genetic instructions to human cells to make antibodies against specific diseases. However, one of the challenges of mRNA vaccines is that they must be kept at cool temperatures to maintain stability during transport and storage.

If the UCR research project is successful, it could make possible not only edible mRNA vaccines, but also an mRNA vaccine capable of being stored at room temperature.

“I’m very excited about all this research,” Giraldo said. “I think it could have a huge impact on people’s lives.”

The research project is being supported by a US$500,000 grant from the US National Science Foundation.