Only mRNA and vector virus vaccines for protection against COVID-19 are currently on the market in Europe. Protein-based vaccines are to be added in the coming months, although their effectiveness has yet to be proven. The previous manufacturing processes are complex. The mRNA technology requires highly specialized nanolipid particles and the vector virus process requires that harmless adenoviruses can be grown and their DNA exchanged.
Bacterium brings genes into the plant
The pharmaceutical companies Medicago and GlaxoSmithKline (GSK) now want to produce a new corona vaccine with the help of plants – specifically with Nicotiana benthamiana, a tobacco-like plant that is actually native to Australia. The project is being researched with McGill University.
Called CoVLP, the vaccine can be easily extracted from the leaves after the plant has grown. Before that, the researchers use a bacterium (Agrobacterium tumefaciens) to transfer genes from the spike glycoprotein of SARS-CoV-2 into the plant, which then forms it in its cells.
Large quantities of robust vaccine
The advantage of the technique is that it could potentially deliver large amounts of vaccine. CoVLP is a so-called virus-like particle vaccine, which together with an adjuvant, i.e. an auxiliary substance, is supposed to stimulate the immune defense against COVID-19. In a currently ongoing phase 1 study, however, it is also being tested whether the vaccine alone is sufficient or whether two adjuvants are required. The vaccine should be easy to handle and can be stored at 2 to 8 degrees plus temperature without it becoming unusable.
The ongoing study by Medicago and GSK in Canada on subjects between the ages of 18 and 55 (180 people, divided into nine groups) showed mild to moderate side effects, such as those from AstraZeneca. The use of the adjuvants in particular showed good formation of neutralizing antibodies. The titer was ten times as high as in the serum of people who had already survived COVID-19 disease. They were vaccinated twice each time – at an interval of 21 days. According to the in Nature Medicine published study, the results are so good that they could be commercialized if all safety criteria are adhered to.