Why the scientists are worried about the new variant of COVID 19: Omicron variant?

• Omicron variant: there are many confirmed cases of a new variant of COVID 19 infection in South Africa, Botswana and Hong Kong, and Europe.
• The World Health Organization (WHO) designated B.1.1.529 & named it “Omicron” on November 26, 2021.
• Omicron genome sequence:
  • Around 50 unusual heavy mutations across the entire genome.
  • > 30 mutations in the part of the genome that codes for its spike protein that allows the virus to invade its host cells.
    • The receptor-binding domain (RBD) part of the spike binds to a receptor ACE2 on the membrane of human cells.
      the crucial target for COVID-19 vaccines is RBD to prevent the virus from infecting cells.
    • Mutations in the RBD part of the genome.
      1. The Beta variant has 3 mutations
      2. The Delta variant has 2 mutations
      3. The Omicron varient has 15 mutations
  • Several mutations induced resistance to neutralizing antibodies including therapeutic monoclonal antibodies.
  • A mutation is associated with resistance to the innate immune system.
• Origin of Omicron variant: It’s speculated that the Omicron variant might have evolved from an unvaccinated individual with a compromised immune system & an unvaccinated population gives the virus millions of opportunities & enough time to replicate, adapt against our immune system select more fit variants.
• Predicted effects of the mutations:
  • Evade the immune system: prevent antibodies production by vaccines through vaccination or an encounter with an older variant of the virus or resistance against neutralizing antibodies or resistance to innate immunity
  • Enhanced transmissibility & efficient entry into host cells.
  • Emphasis:  the full impact of the combination of these mutations remains uncertain (combination of mutations might yield into either a severe form or a very mild form of SARS in reality) & currently there is no data on how much protection the available vaccines will provide against Omicron.

Do you want to read more about this topic?

1. Heavily mutated Omicron variant puts scientists on alert, Nature 600, 21 (2021), doi: https://doi.org/10.1038/d41586-021-03552-w.