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The current surge in Covid-19 infections in China, is believed to be driven by the BF.7 sub-variant of Omicron that is circulating over there.

  • The dominant virus strain in China is BF.7, a sub-variant of Omicron that has been in circulation for over a year now.
  • There are over 500 Omicron sub-variants currently in circulation.
  • BF.7 is the name for the BA., which itself has evolved from the BA.5 sub-variant.
  • BF.7 is not unique to China.
  • It accounted for over 5% of the cases in the US in October, 2022 and over 7% of the cases in the UK.
  • When viruses mutate, they create lineages and sub-lineages— like the main trunk of the SARS-CoV-2 tree sprouting branches and sub-branches.
  • A research study reported that the BF.7 sub-variant has a 4.4-fold higher neutralisation resistance than the original D614G variant— meaning that in a lab setting, antibodies from a vaccinated or infected individual were less likely to destroy BF.7 than the original Wuhan virus that spread worldwide in 2020.
  • A higher neutralisation resistance means there is a higher likelihood of the variant spreading in a population and replacing other variants.

How are New Variants Formed

  • When a virus multiplies, it doesn’t always manage to produce an exact copy of itself.
  • This means that, over time, the virus may start to differ slightly in terms of its genetic sequence.
  • Any changes to the viral genetic sequence during this process is known as a Mutation.
  • Viruses with new mutations are sometimes called Variants. Variants can differ by one or multiple mutations.
  • When a new variant has different functional properties to the original virus and becomes established in a population, it is sometimes referred to as a New Strain of the virus.
  • All strains are variants, but not all variants are strains.