Antibodies that can block Omicron identified
GS Paper - 2 (Diseases)
Scientists have identified antibodies that neutralise Omicron and other variants of coronavirus by targeting areas that remain essentially unchanged as the virus mutates. The research, published in the journal Nature, may help design vaccines and antibody treatments that will be effective against not only Omicron but other variants that may emerge in the future.
- 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, University of Washington School of Medicine said.
- The Omicron variant has an unusually high number of 37 mutations in the spike protein, which the virus uses to enter and infect the human cells.
- To assess the effect of these mutations, the researchers engineered a disabled, nonreplicating 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.
- The researchers first looked to see how well the different versions of the spike protein were able to bind to protein on the surface of cells that the virus uses to latch onto and enter the cell. This protein is called the angiotensin converting enzyme-2 (ACE2) receptor.
- They found the Omicron variant spike protein was able to bind 2.4 times better than spike protein found in the virus isolated at the very beginning of the pandemic.
- That is not a huge increase but in the SARS outbreak in 2002-2003, mutations in the spike protein that increased affinity were associated with higher transmissibility and infectivity.
- They did this by using antibodies from patients who had previously been infected with earlier versions of the virus, vaccinated against earlier strains of the virus, or had been infected and then vaccinated.