Researchers researchers are studying a new type of immunisation that may be able to protect against many variants of coronaviruses.
in the laboratory of Pamela Björkman, the David Baltimore professor of biology and bioengineering, are working on developing vaccines for a range of related coronaviruses, with the aim of preventing future pandemics.
Led by graduate student Alex Cohen, a Caltech team has designed a protein-based 60-subunit nanoparticle onto which pieces of up to eight different types of coronavirus have been attached. When injected into mice, this vaccine induces the production of antibodies that react to a variety of different coronaviruses, including similar viruses that were not presented on the nanoparticle.
This vaccine platform, called a mosaic nanoparticle, was developed initially by collaborators at the University of Oxford. The nanoparticle is shaped like a cage made up of 60 identical proteins, each of which has a small protein tag that functions like a piece of velcro. The research is described in a paper in the journal Science.
Displaying eight different coronavirus spike fragments with this particle platform generated a diverse antibody response. After inoculation, the antibodies subsequently produced by mice were able to react to many different strains of coronavirus.
Cohen said: “If we can show that the immune response induced by our nanoparticle technology indeed protects against illness resulting from infection, then we hope that we could move this technology forward into human clinical trials, though there are a lot of steps that need to happen between now and then.
“We don’t envision that this methodology would replace any existing vaccines, but it’s good to have many tools on hand when facing future emerging viral threats.”
The antibodies were reactive to related strains of coronavirus that were not present on the nanoparticle.
The researchers suggest that, by presenting the immune system with multiple different coronavirus variants, it learns to recognise common features of coronaviruses and could potentially react to a newly emerging coronavirus.
Björkman said: “Unfortunately, SARS-CoV-2 is unlikely to be the last coronavirus to cause a pandemic.
“We are hopeful that this technology could be used to protect against future animal coronaviruses that cross into humans.
“In addition, the nanoparticles elicit neutralising responses against SARS-CoV-2, so it could be possible to use them now to protect against COVID-19, as well as other coronaviruses with pandemic potential.”