Scientists have discovered human antibodies that can kill multiple different coronaviruses, paving the way for the development of a pan-coronavirus vaccine.
According to the University of Washington study, these antibodies have been found in some persons who have recovered from COVID-19.
The study, which was published in the journal Science, is based on five human monoclonal antibodies that can cross-react with a variety of beta-coronaviruses.
The researchers looked into COVID-19 convalescent donors’ memory B cells. Memory B cells are white blood cells that recognize and react to pathogens that have previously attempted to harm the host.
The scientists chose to focus on one of the five promising antibodies they discovered, called S2P6. This human monoclonal antibody displayed outstanding breadth, according to molecular structure and functional research, as it was able to kill three separate subgenera of beta-coronaviruses. It did so, according to the researchers, by preventing the virus from fusing with cell membranes.
These antibodies attack a component in the spike protein of these viruses called the stem helix. The capacity of the virus to conquer host cells is dependent on the spike protein.
During the evolution of certain coronaviruses, the stem helix in the spike protein has remained conserved. That means it is less susceptible to genetic alterations and is comparable in different coronaviruses, according to the main scientist Dora Pinto of the University of Washington’s School of Medicine in Seattle.
These include bat-borne diseases that have evolved into hazardous human pathogens, a subgenus that causes a fatal human lung illness spread by dromedary camels, and a few other subgenera that give basic common cold symptoms.
The researchers next used hamsters to see if the S2P6 stem helix antibody might protect them from SARS-CoV-2 by giving it to them 24 hours before exposure. They discovered that this antibody lowered SARS-CoV-2 viral load by limiting virus entrance and increasing antiviral and virus-clearing cellular immune responses.
Researchers looked at plasma from pre-pandemic human samples, as well as COVID-vaccinated and COVID-recovered people, to examine how frequently the stem-helix targeting antibodies occurred.
People who had recovered from COVID-19 and subsequently were vaccinated had the highest frequency. Overall, the findings of this investigation suggest that, while SARS-CoV-2 does generate plasma stem-helix antibody responses, they are somewhat infrequent.
