GSK to develop plant-based COVID-19 vaccine with Canada's Medicago

(Reuters) - The world's largest vaccine-maker GSK <GSK.L> has put its vaccine booster technology to work in a potential new COVID-19 shot, to be developed with a Canadian biopharmaceutical company backed by tobacco company Philip Morris <PM.N>.

Rather than developing its own vaccine in the global race to combat the pandemic, GSK has instead focused on contributing its adjuvant technology to at least seven other global companies, including Sanofi <SAY.PA> and China's Clover.

The latest deal, with Canadian firm Medicago, uses plant-based technology that differs from GSK's other coronavirus-partnerships and boosts the London-listed company's chances of finding a successful candidate and scaling production relatively quickly.

There are no approved vaccines for the respiratory illness caused by the new coronavirus, but 19 vaccines are being trialled in humans globally and some treatments, such as Gilead's <GILD.O> remdesivir, have been approved in certain regions.

Medicago's approach, already used in a flu vaccine awaiting Canadian approval, takes the leaves of a plant as bioreactors to produce one of the three spike proteins of the novel coronavirus, the S-spike, which can be then used in the vaccine with GSK's adjuvant.

GSK said on Tuesday the companies aimed to make their vaccine available in the first half of next year and produce about 100 million doses by the end of 2021. An early-stage human trial of three different dosage levels is expected to begin in mid-July.

Adjuvants, or efficacy boosters, are added to some vaccines to increase the immune response with the aim of achieving more lasting immunity against an infection.

Medicago, headquartered in Quebec City, Canada, is privately owned. PMI has a 33% stake, and Mitsubishi Tanabe Pharma holds the remainder.

PMI has said it is evaluating options for its stake in Medicago. It was not immediately available for further comment.

(Reporting by Pushkala Aripaka in Bengaluru and Alistair Smout in London; Additional reporting by Muvija M and Siddharth Cavale; Editing by Shinjini Ganguli and Barbara Lewis)