Medicago, GSK plant-based COVID vax shows high efficacy

Dec. 7, 2021

Canadian drug developer Medicago announced positive efficacy and safety results from the global phase 3 trial of its plant-based COVID-19 vaccine candidate, developed in combination with GlaxoSmithKline’s pandemic adjuvant.

The overall vaccine efficacy rate in the phase 3 trial against all variants of SARS-COV-2 was 71%. Importantly, the vaccine demonstrated efficacy of 75.3% against COVID of any severity for the globally dominant Delta variant. Efficacy was 88.6% against the Gamma variant. The Omicron variant was not circulating during the study.

This sets the Medicago vaccine candidate apart, as most published phase 3 efficacy trials for currently licensed COVID vaccines were conducted before the delta and gamma variants were circulating. Medicago launched the phase 3 portion of the trial back in March with over 24,000 participants aged 18 years or above in Canada, U.S., UK, Mexico, Argentina and Brazil.

Medicago's plant-based vaccine development process uses living plants as bioreactors to produce a non-infectious particle that mimics the target virus. The process enables vaccines to be produced in large amounts, quickly and affordably — which may be key to vaccination efforts in underdeveloped countries.

The company said it will imminently seek regulatory approval from Health Canada as part of its rolling submission. The Canadian health regulator accepted Medicago’s application for a real-time review of the only home-grown COVID-19 vaccine back in April.