New vaccine developments (30-03-2021)
Canada-based Medicago is developing the CoVLP (Coronavirus-Like-Particle) vaccine, the efficacy of which is still
unknown. The proposed dose administration guideline is two doses three weeks apart by intramuscular injection.
The vaccine is stable at refrigerator temperatures. The effort is being conducted using a plant called Nicotiana
benthamiana, a wild species related to tobacco. Plant leaf cells infected with a virus carrying SARS-CoV-2 protein
genes are used. The proteins are produced in the leaves of the plant.
In July 2020, Medicago initiated phase 1 trials of this COVID-19 vaccine, combined with adjuvants to stimulate the
immune system's response to viral proteins. That study found that an adjuvant made by GSK produced promising
levels of antibodies in volunteers. On 23 October, the company announced that it had reached an agreement with
the Canadian government to supply 76 million doses. On 12 November 2020, a phase 2/3 trial of the vaccine began.
On 16 March 2021, Medicago and GSK began a phase 3 trial.
Available at: https://www.clinicaltrials.gov/ct2/show/NCT04636697
At the same time, Cuba's Center for Genetic Engineering and Biotechnology began a test in late November using a
coronavirus vaccine called Abdala, which consists of a part of the coronavirus spike protein known as the receptorbinding
domain. On 1 February, the Center held a press conference to announce the start of a phase 2 trial, and on
18 March began a phase 3 trial that will recruit up to 48,000 participants.
Live attenuated vaccines, which are usually highly immunogenic, are also in development. They cause an immune
response similar to that generated by an infection. For SARS-CoV-2, the single-dose intranasal COVI-VAC vaccine is
in a phase 1 clinical trial. Its developers claim to have introduced 283 silent mutations in the gene coding for the
virus's spike protein. Additional information about the clinical trial is available at:
Another COVID-19 vaccine designed to prevent infection is the orally administered VXA-CoV2-1 vaccine, consisting
of a non-replicating vector virus, specifically a modified adenovirus encoding the SARS-CoV-2 and nucleocapsid S
protein. This vaccine is undergoing clinical evaluation in a phase 1 trial.
More on this clinical trial can be found at:
At present, it is not known whether such a wide range of next-generation COVID-19 vaccines will be needed;
however, it is worth highlighting the extensive effort that has been made at the global level to develop new
vaccines. The WHO COVID-19 candidate vaccine landscape and tracker indicates that, as of 16 March 2021, there
were 82 vaccines under clinical evaluation and 182 in the preclinical stage. Information available at: