Japanese researchers claimed that the DNA-based vaccine they are developing have successfully neutralized SARS-CoV-2.
Researchers from the Osaka University in Osaka, Japan used two methodologies in the study: the pseudovirus assay as well as the binding assay, which involves Receptor Binding Domain recombinant protein (RBD) with angiotensin-converting-enzyme 2 (ACE2).(Photo : REUTERS/Dado Ruvic)
A woman holds a small bottle labeled with a “Vaccine COVID-19” sticker and a medical syringe in this illustration taken April 10, 2020.
However, the study is still on the preliminary stage, published on October 21 in bioRxiv, a pre-print server for scientific reports, which are not yet peer-reviewed. Thus, the Osaka University study cannot be regarded as conclusive or treated as recognized data.
DNA-induced vaccine against COVID-19
The Japanese researchers developed a DNA-based vaccine that targets the glycoprotein on the spike of SARS-CoV-2 spike, which is used to attach to the cell’s ACE2 receptor. The virus uses the ACE2 to enter healthy human cells and infect the body.
Researchers got the DNA vaccine, called pVAX1, from Invitrogen in the United States. They also acquired the SARS-CoV-2 virus RNA from the National Institute of Infectious Disease. They also obtained the alum phosphate, which they used as adjuvant in the study, from U.S.-based company InVivogen.
Then, researchers used an in-silico gene optimization to develop a highly-optimized DNA sequence encoding of the virus’ spike glycoprotein. This optimization algorithm boosts expression and immunogenicity or the body’s immunity response. The DNA sequence encoding was injected into the pVAX1 plasmid.
They measured antibody production using an antigen-specific enzyme-linked immunosorbent assay to denote the response as well as an antigen-dependent cell activation using an enzyme-linked immunosorbent spot (ELISpot) assay to analyze cellular responses. Similarly, they used the pseudovirus neutralization assays to assess immune responses.
DNA-based vaccine Phase 1/2
Currently, the vaccine is early phase of the clinical trial in Japan. Fortunately, preliminary data shows the vaccine produced no adverse effects, which is similar to safety profile data in previous studies of DNA vaccines used for other infectious diseases.(Photo : Soraie8288 / Wiki Commons)
Osaka University Toyonaka Campus Main Entrance
Pre-clinical trial’s initial results show that the immunogenicity of the DNA vaccine, which target on S-protein can be used as basis to evidence, so researchers can proceed with clinical trials. They believe DNA-based vaccines against COVID-19 may alleviate the current health crisis that continues to ravage the world.
As of this writing, there are about 41.7 million confirmed COVID-19 cases across the globe with at least 1.14 million deaths. In the U.S., there are already 8.46 million cases and at least 223,000 deaths reported.
The vaccine’s future Phase 3 trial in the U.S.
On October 22, Hilda Bastian, a health advocate and scientists shared in Twitter that the DNA vaccine being developed by Osaka University may be soon undergo Phase 3 trial in the U.S. She pointed out signs of such possibility.
These include the publication of the preprint and the announcement of AnGes, the partner company of Osaka University in developing this COVID-19 vaccine, in Sept that it had a deal to collaborate with a U.S. company Brickell Biotech, Inc. in preparation for Phase 3 trials once the phase 1/2 goes well. Also, AnGes projected that the vaccine will get into the market by 2021.