QUEBEC CITY, Quebec — Scientists claim to have created a COVID vaccine — from a tobacco plant. It boosts antibodies tenfold, say researchers, and could combat the global vaccine shortage. Clinical trials are being launched across the world after initial successful results.
The vaccine is unique because it is derived from Nicotiana benthamiana, a plant that grows in Australia. It contains nicotine and is used as a stimulant by the indigenous people. Now scientists genetically engineered the shrub to fight the coronavirus. This opens the door to mass production of the vaccine on an industrial scale.
The vaccine produces a virus-like particle (VLP) that mimics the potentially lethal spike protein that hooks onto cells. The outer structure is the same, making it easily recognizable for the immune system. But it is harmless, as there is no genetic material for it to reproduce and spread inside the body.
The 180 Canadian study-participants, aged 18 to 55, received two doses of the vaccine, named CoVLP, three weeks apart. After six weeks, they produced numbers of neutralizing antibodies up to ten times higher than those seen in recovering COVID-patients. The vaccine worked best when combined with a chemical cocktail used in routine flu drugs, known as AS03.
“The plant-derived candidate vaccine was well-tolerated and elicited an immune response,” says the study’s corresponding author Dr. Brian Ward of biopharmaceutical company Medicago, Quebec City, in a statement per South West News Service. The vaccine cannot cause an infection but still teaches the body how to fight it, leading to immunity.
“Several COVID vaccines are being deployed, but the global need greatly exceeds the supply, and different formulations might be required for specific populations,” adds Dr. Ward. All formulations were well tolerated, with side effects short-lived and mild to moderate.
“Although considerable progress has been made in caring for patients, current treatment options remain relatively limited,” he adds. “No single vaccine can be produced in sufficient quantities to address the global need fast enough, and different formulations may be required for varied populations and environments. One such formulation is CoVLP, a virus-like-particle candidate vaccine that incorporates the SARS-CoV-2 spike protein, produced in the plant, Nicotiana benthamiana.”
The original volunteers are being monitored for 12 months. A two-dose regime of CoVLP with AS03 has entered into a larger phase two in studies in Canada, the U.K., Brazil, and the USA. Similar projects are also being planned for other countries in Europe and Latin America, where cases are increasing.
“Creating a sufficient supply of COVID-19 vaccines within the next year is a challenge which will require multiple approaches, with different technologies,” said says Dr. Bruce Clark, president and CEO of Medicago. “Our proven plant-based technology is capable of contributing to the collective solution to this public health emergency.”
Producing VLP vaccines in plants is a complex process, but it takes just six to eight weeks, much quicker compared to the six months in a chicken egg, another source of vaccines. It also eliminates ethical concerns surrounding reliance on animal products.
The scientists genetically engineered a special plant-infiltrating bacterium called Agrobacterium to turn the nicotine plants into miniature VLP “factories.” Specific sequences of viral DNA that produce the coronavirus’ outer structure proteins are inserted into its genome. Then, Agrobacterium is allowed to infect the plant.
Once inside the cells, the genetically modified Agrobacterium delivers the inserted viral DNA to the plant so it can use it as a template to produce the virus-like particle. Once the plant is infected by the Agrobacterium, it will reliably produce the virus-like particles. All that’s left is harvesting the plant and purifying the VLPs from its tissue.
The study is published in the prestigious British journal Nature Medicine.
SWNS writer Mark Waghorn contributed to this report.