Plant-Based Vaccines: The Way Ahead?

Zacharie Leblanc,Peter Waterhouse,Julia Bally

doi:10.3390/v13010005

Abstract

Severe virus outbreaks are occurring more often and spreading faster and further than ever. Preparedness plans based on lessons learned from past epidemics can guide behavioral and pharmacological interventions to contain and treat emergent diseases. Although conventional biologics production systems can meet the pharmaceutical needs of a community at homeostasis, the COVID-19 pandemic has created an abrupt rise in demand for vaccines and therapeutics that highlight the gaps in this supply chain’s ability to quickly develop and produce biologics in emergency situations given a short lead time. Considering the projected requirements for COVID-19 vaccines and the necessity for expedited large scale manufacture the capabilities of current biologics production systems should be surveyed to determine their applicability to pandemic preparedness. Plant-based biologics production systems have progressed to a state of commercial viability in the past 30 years with the capacity for production of complex, glycosylated, “mammalian compatible” molecules in a system with comparatively low production costs, high scalability, and production flexibility. Continued research drives the expansion of plant virus-based tools for harnessing the full production capacity from the plant biomass in transient systems. Here, we present an overview of vaccine production systems with a focus on plant-based production systems and their potential role as “first responders” in emergency pandemic situations.

Highlights

Academic Editor: Jeanmarie Verchot Received: 21 November 2020 Accepted: 19 December 2020 Published: 22 December 2020Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.Biopharming is the use of a living system as a host for the manufacture of non-natively produced, biologic drugs
This technological development was a boon for commercialization and Chinese Hamster Ovary (CHO) cells were quickly adopted as the preferred large-scale production host for complex therapeutic molecules
In 2017, the monoclonal antibodies market was valued at 123 billion USD with 87% of newly approved mAb products being produced in CHO cells [5]

Summary

Introduction

Academic Editor: Jeanmarie Verchot Received: 21 November 2020 Accepted: 19 December 2020 Published: 22 December 2020. The low infrastructure cost and simple biomass amplification requirements associated with plants compared to fermentation-based systems spurred an immense amount of interest in the possibilities of using plants as cheap biofactories and, by using the appropriate crop species, edible vaccines This was soon followed by efforts to demonstrate the capacity for scaling plant-based biologics production in fields by using stably transformed crop plants such as maize, barley, safflower, and rice as production hosts. Protalix Biotherapeutics of Israel uses a transgenic carrot cell suspension system to produce taliglucerase alfa, for treatment of Gaucher disease [17] Their production system is bioreactor-based and claims to have lower initial investment and running costs compared to mammalian-based systems [18]. Viral vector systems have provided the highest boosts in product yield in this transient system

Viral Expression Vectors in Plants

Systems for Vaccine Manufacture

Findings

Conclusions and Future Perspectives