Tobacco-grown COVID-19 vaccine moves ahead

Medicago and GlaxoSmithKline have begun a Phase 3 study of Medicago’s COVID-19 vaccine, which comprises recombinant spike protein derived from plants and an adjuvant developed by GSK. The companies aim to enroll 30,000 people in the placebo-controlled trial of a two-dose vaccine regimen. Medicago exposes tobacco plants 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 spent several days making viruslike particles, which are extracted and purified.