The World Health Organization provides a draft landscape document outlining the different Covid-19 candidate vaccines. So far there are 16 candidate vaccines in clinical evaluation, and 125 candidate vaccines in preclinical evaluation.
While they do make this list for informational purposes only, the WHO makes it a point to let readers know that “Inclusion of any particular product or entity in any of these landscape documents does not constitute, and shall not be deemed or construed as, any approval or endorsement by WHO of such product or entity (or any of its businesses or activities).”
Taking a look at a few here, the only candidate that appears to be in a Phase 3 clinical trial is a Nonreplicating Viral Vector Candidate from University of Oxford/AstraZeneca. This phase III study is a randomized controlled trial to determine safety, efficacy, and immunogenicity of the non-replicating ChAdOx1 nCoV-19 vaccine. This is the same vaccine that was in the news and on our own blog here for notably protecting monkeys against COVID-19 pneumonia.
CanSino Biological Inc./Beijing Institute of Biotechnology is developing another Nonreplicating Viral Vector Candidate which is the Adenovirus Type 5 Vector Vaccine – it is important to note that adenovirus vectors are the most commonly employed vector for cancer gene therapy. This vaccine is in a Phase II clinical study that is a randomized, double-blinded, placebo-controlled. \
An RNA Vaccine is being developed by Moderna/NIAID which is in Phase II clinical trials. If you read our previous blog post about mRNA vaccines, you’ll remember that The mNRA – Messenger Ribonucleic Acid Vaccine – is an entirely new vaccine that was developed and approved for Coronavirus. “An RNA vaccine or mRNA vaccine is a novel type of vaccine for providing acquired immunity through an RNA containing vector, such as lipid nanoparticles.” This trial is officially titled, “A Phase 2a, Randomized, Observer-Blind, Placebo Controlled, Dose-Confirmation Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of mRNA-1273 SARS-COV-2 Vaccine in Adults Aged 18 Years and Older”
Lastly, we’ll look at another Phase II study from Novavax which uses a Protein Subunit vaccine candidate. Its official title is “A 2-Part, Phase 1/2, Randomized, Observer-Blinded Study To Evaluate The Safety And Immunogenicity Of A SARS-CoV-2 Recombinant Spike Protein Nanoparticle Vaccine (SARS-CoV-2 rS) With Or Without MATRIX-M™ Adjuvant In Healthy Subjects”. “Protein based subunit vaccines present an antigen to the immune system without viral particles, using a specific, isolated protein of the pathogen” The particular protein being used here in this study is the Spike protein we see mentioned so often when discussing Covid-19.
There are many more candidate vaccines in the works listed by the WHO, but these seem to be the most promising as they are in Phase 2 trials, with The University of Oxford’s candidate being the most advanced in a Phase III trial. Please check back with the ABN blog for more information on these vaccine candidates as more information is released upon the completion of these trials.