Plant-based SARS-CoV-2 Vaccine Candidates Exhibit Broad Spectrum Protection During Trials

A SARS-CoV-2 vaccine developed using a relative plant of the tobacco proved to be successful after it exhibited cross-neutralization against the Delta and Omicron variants of the virus. The findings support the development of multivalent vaccines for broad spectrum protection of SARS-CoV-2 through plant biopharming.

Experts recognize plant biopharming for its scalability, speed, versatility, and low-production costs, making it a promising molecular pharming vaccine platform for human health. The method produces virus-like particles (VLPs). They are considered safe and efficacious because their non-replicating shells lack the viral genome but mimic the native virion with repetitive epitopes to induce both innate and adaptive immunity.

The idea of molecular pharming led the scientists from South Africa to create vaccine candidates using Nicotiana benthamiana-produced SARS-CoV-2 VLPs which exhibited the S-protein of the Beta variant of concern. New Zealand white rabbits received the vaccine candidates at a dose of 5ug to test immunogenicity. This resulted in robust neutralizing antibody responses after booster vaccination. The vaccine candidates also conferred cross-immunity against the Delta and Omicron variants.

The study demonstrated the successful development of a plant-produced VLP vaccine composed of a cocktail of selected VLPs that can result in broad spectrum protection against SARS-CoV-2. The scientists recommended a glycosylation profile of clinical grade SARS-CoV-2 VLPs for future studies.

The full paper can be found in Vaccine.