A group of researchers from the Higher Council for Scientific Research (CSIC) with experience in developing vaccines against HIV, Ebola, Zika or Chikungunya focus their efforts on a vaccine for the new coronavirus SARS-CoV-2, responsible for the COVID-19 pandemic.
The strategy of the team of the National Center for Biotechnology (CNB-CSIC) led by the scientist Mariano Esteban is to generate viral vectors based on a modification of the Vaccinia virus or vaccine virus, used in the eradication of smallpox.
The team of scientists is working to create modified Vaccinia viral vectors that contain a SARS-CoV-2 surface protein and that are capable of generating an immune response with the ability to protect the body from exposure to the coronavirus.
Based on the publication of the first sequences of the virus genome, in early January of this year, researchers have chosen to use the protein S (spike), which is on the surface of the virus and serves to bind to the cell of the virus. host, in addition to being the largest inducer of protective antibodies.
“Multiple virus plaques have been isolated to achieve those containing the protein S gene. It now remains to be shown that this protein is stable and has the ability to induce the specific immune response in an animal model, including the production of antibodies that neutralize the virus, “explains Esteban.
Another methodology to get the vaccine
By not using the full SARS-CoV-2 virus, researchers can work under conditions of a lower level of biological safety and, therefore, less experimental complexity is required when developing the vaccine.
As the researcher points out, “our approach is different from that of Luis Enjuanes’s group (also from the CNB), since it uses only a viral component and not the complete virus, but it is the most important component from the immune and protection”.
The approach from the Vaccinia virus has managed to induce high protection with a single dose in vaccines developed by this group against Ebola, Zika and Chikungunya. In addition, the virus vector, which has been used in numerous clinical trials, is already licensed as a smallpox vaccine by U.S. regulatory agencies. Food and Drug Administration (FDA), of the USA, and the European Medicines Agency (EMA).
“That is why we believe that the MVA-COVID-19 vaccine would be safe and could be administered to all types of population in all age groups, including people with immunodeficiencies,” concludes the scientist.