The universal vaccine against all coronaviruses

A specific portion of the spike protein of the SARS-CoV-2. That would be the target of a pan-coronavirus vaccine, or “universal”, that is, that it could defend us against different types of coronavirus, the new variants, and thus help us to face the current, but also the future, pandemics. To support it are researchers from the Francis Crick Institute in London which have shown, in some preliminary tests, as a very specific region of the spike protein of Sars-Cov-2, different from that at the base of the others vaccines, is a promising target for the development of a vaccine capable of triggering an immune response that recognizes and neutralizes a whole range of different coronaviruses, thus preventing the viruses from entering host cells and replicating. The study was published on Science Translational Medicine.

The research focused on the so-called S2 subunit of the spike protein of Sars-Cov-2, the region that binds it to the virus membrane and allows it to fuse with the host cell membrane. In particular, after some preliminary tests conducted both on mice and in test tubes in which the preliminary Sars-cov-2 S vaccine was studied, the researchers found that the experimental compound was able to create antibodies capable of neutralizing a series of coronavirusboth animal and human, such as the seasonal “common cold” coronavirus Hcov-Oc43, the original Sars -Cov-2 strain, the dominant D614g mutation in the first wave, Alpha, Beta, Delta, Omicron and two bat coronaviruses. “The S2 region of the spike protein is a promising target for a potential pan-coronavirus vaccine because this region is much more similar between different coronaviruses than subunit 1”explains Kevin Ngfirst author of the research. “It is less prone to mutations, and therefore a vaccine that targets this region should be more robust.”

So far, remember, the S2 of the spike protein It has been poorly studied as a basis for the development of a pan-coronavirus vaccine, because some critical targets within it are only revealed after the virus binds to a cell, in an S1-mediated process. As a result, S2 antibodies can have less opportunity to neutralize the virus compared to antibodies that target S1. “The expectation for an S2 targeted vaccine is that it could offer some protection against all current and future coronaviruses “adds George Kassiotis, one of the authors of the research. “This differs from vaccines that target the more variable S1 region which, while effective against the corresponding variant they are designed against, are less able to block other variants or a wider range of coronaviruses.”

The road to the development of a vaccine universal is, however, still long. In fact, researchers will have to continue testing S2 antibodies against various coronaviruses to find the right path in designing and testing a potential vaccine. “Although a potential S2 vaccine would not prevent people from being infected, the idea is that it will help their immune systems provide sufficient protection to survive the initial infection, and respond to a future coronavirus infection.”concludes author Nikhil Faulkner.