In a study from Penn State University, scientists found a vaccine design approach that could protect against new variants of SARS-CoV-2 (the virus that causes COVID-19) but also potentially protects against other coronaviruses.
This is one step closer to an adaptation-proof COVID-19 vaccine.
SARS-CoV-2’s surface spike protein—a major antibody target—allows the virus to enter host cells by engaging with a receptor called angiotensin-converting enzyme 2.
Existing vaccines target the receptor binding domain (RBD) of the spike protein, but the susceptibility of RBD to mutations provides escape routes for the virus from neutralizing antibodies.
The team identified areas of the spike protein that are least likely to mutate and used that information to engineer new proteins.
This could be used to develop a vaccine that protects more broadly against not only future COVID-19 variants but potentially other related coronaviruses.
Just weeks after the Centers for Disease Control and Prevention approved a new bivalent COVID-19 vaccine, the researchers published a study about the design and efficacy of their immunogens, which target the virus in a different way.
Unlike current vaccines on the market, these immunogens are designed based on conserved regions of the spike protein, areas that are less susceptible to mutation.
The team designed the immunogens by using computational biology to identify three regions of the spike protein that remain conserved in millions of theoretical mutations that could occur.
These areas, called epitopes, were then matched and grafted, or attached, to protein scaffolds, which provided stability to the epitopes while in solutions.
The immunogens were then optimized through various design modifications, including stabilizing mutations.
The team used the recombinant expression, a technique where bacteria are given the genetic instructions to make proteins, to create the virtually designed immunogens.
In the end, the researchers developed four stable immunogen designs which were used to immunize mice, who then produced antibodies against SARS-CoV-2.
Each design produced antibodies to varying degrees, but one design, ED2, had a robust immune response.
Through further testing, the researchers found these antibodies bound to the SARS-CoV-2 spike protein.
They found that the antibodies in COVID-19 patient serum samples were able to bind to the ED2 immunogens, demonstrating that they might also be used for diagnostic applications.
According to researchers, further studies will be done to optimize the design and immune response of the immunogens. Once perfected, they could someday be used as vaccine candidates in clinical trials.
If you care about COVID, please read studies about vitamin D deficiency linked to severe COVID-19 and death, and why diabetes is a big risk factor for severe COVID-19.
For more information about COVID, please see recent studies about people who have less severe COVID-19 infections, and results showing people with mild COVID-19 should use antiviral drug.
The study was conducted by Nikolay Dokholyan et al and published in Advanced Functional Materials.
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