All You Need To Know About Indian Plant-Based Covid-19 Vaccine

Scientists in India are preparing to begin clinical trials of a plant-based vaccine against Covid-19. According to a top official of India's plant genome research authority, the experts are examining a close relative of the tobacco plant, Nicotiana benthamiana, to build a platform to manufacture Covid-related antigens to elicit the immune response against the SARS-CoV-2 virus.

The research is being carried out by three research groups at the National Institute of Plant Genome Research (NIPGR) in New Delhi, which is part of the Ministry of Science and Technology's Department of Biotechnology, in collaboration with the International Centre for Genetic Engineering and Biotechnology (ICGEB).

According to scientists, antibodies against the so-called N-terminal portion of the SARS-CoV-2 S-glycoprotein contain a receptor-binding domain (RBD), which can effectively disrupt RBD ACE2 (host-receptor) contact. The ACE2 receptor is a protein that allows the novel virus to attach to human cells and infect them.

A spokesperson at NIPGR said: "The leaf extracts of plants expressing the RBD and purified protein will be tested and used for immunisation of mice in collaboration with ICGEB, New Delhi, with different doses to trigger a strong immune response against the virus."

He also stated that "as plant-based vaccines provide ease of administration and monitoring, developing such a vaccine for SARS CoV-2 would assist in executing mass immunisation drives".

Currently, Bharat Biotech's Covaxin, the Indian version of Oxford-AstraZeneca jab—Covishield and Russian vaccine Sputnik V have been given to people in India. Covaxin is an inactivated vaccine that is developed with Whole-Virion Inactivated Vero Cell-derived technology. Covishield has been prepared using the viral vector platform—involving chimpanzee adenovirus. Sputnik V is a vector vaccine based on adenovirus DNA, in which the SARS-CoV-2 coronavirus gene is integrated.

According to Dr Renu Swarup, Secretary, Department of Biotechnology, the vaccine under development is India's first plant-based vaccine against Covid-19. He said: It's an early lead and a very challenging task. Indian scientists are taking up all challenging research while fighting the pandemic."

He also stated that "the current development is in a model system and the vaccine will take some time to develop; if successful, India will be among the first countries to have such a vaccine".

However, other researchers around the world have also been working to develop such plant-based vaccines against Covid-19. For example, Dr Larry Grill, Dean of Research and Research Professor at Keck Graduate Institute in the United States and his colleagues have been working for more than a decade to produce low-cost, plant-derived vaccinations for underdeveloped countries, and they are currently adapting their vaccine for use against Covid-19. In this case, plant viruses are used to make the vaccines developed in Dr Grill's lab.

Canada based Medicago and GlaxoSmithKline in the United Kingdom have started a Phase 3 study of Medicago's Covid-19 vaccine, which consists of recombinant spike protein derived from plants and a GSK adjuvant. According to Medicago's website, the vaccine candidate is in Phase 3 clinical trials since mid-March, and the study is being conducted in North America, Latin America and Europe.

Tobacco plants are exposed to a plant-specific bacterial vector that encodes for a gene sequence of choice—in this case, the key protein used by SARS-CoV-2 to enter human cells. The plants worked for several days to produce virus-like particles, which were extracted and purified.