An international team of scientists have identified antibodies that neutralize Omicron and other SARS-CoV-2 variants. These antibodies target areas of the virus spike protein that remain essentially unchanged as the viruses mutate.
The Omicron variant has 37 mutations in the spike protein, which it uses to latch onto and invade cells. The highly unusually high number of mutations likely explain why the variant has been able to spread so rapidly, to infect people who have been vaccinated and to reinfect those who have previously been infected.
By identifying the targets of these “broadly neutralizing” antibodies on the spike protein, it might be possible to design vaccines and antibody treatments that will be effective against not only the omicron variant but other variants that may emerge in the future, said David Veesler, an investigator with the Howard Hughes Medical Institute.
In the study, the team tested a larger panel of antibodies that had been generated against earlier versions of the virus and identified four classes of antibodies that retained their ability to neutralize Omicron.
Members of each of these classes target one of four specific areas of the spike protein present in not only SARS-CoV-2 variants but also a group of related coronaviruses, called arboviruses. These sites on the protein may persist because they play an essential function that the protein would lose if they mutated. Such areas are called “conserved”
The finding that antibodies can neutralize via recognition of conserved areas in so many different variants of the virus suggests that de- signing vaccines and antibody treatments that target these regions could be effective against a broad spectrum of variants that emerge through mutation, Veesler said.
“This finding tells us that by focusing on antibodies that target these highly conserved sites on the spike protein, there is a way to overcome the virus’ continual evolution,” said Veesler, Associate Professor of biochemistry at the University of Washington School of Medicine in Seattle. The findings were published in the journal Nature.
Further, the team also engineered a disabled, non-replicating virus, called a pseudovirus, to produce spike proteins on its surface, as coronaviruses do. They then created pseudoviruses that had spike proteins with the Omicron mutations and those found on the earliest variants identified in the pandemic.