BF.7 Variant of the Coronavirus

• 22 Dec 2022

Why in News?

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.

What is the BF.7 Variant of Coronavirus?

• 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.5.2.1.7, 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.

UPSC Civil Services Examination, Previous Years Question (PYQ)

Q. In the context of vaccines manufactured to prevent COVID-19 pandemic, consider the following statements: (2022)

1. The Serum Institute of India produced COVID-19 vaccine named Covishield using mRNA platform.
2. Sputnik V vaccine is manufactured using vector-based platform.
3. COVAXIN is an inactivated pathogen-based vaccine.

Which of the statements given above are correct?

(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Ans: (b)

Exp:

• COVISHIELD vaccine is based on the platform which uses a recombinant, replication-deficient chimpanzee adenovirus vector encoding the SARS-CoV-2 Spike (S) glycoprotein. Following administration, the genetic material of part of coronavirus is expressed which stimulates an immune response. Hence, statement 1 is not correct.
• Sputnik V is the world's first registered vaccine based on a well-studied human adenovirus vector platform. It has been approved for use in 71 countries with a total population of 4 billion people. The vaccine is named after the first Soviet space satellite. The vaccine’s efficacy is 97.6%, based on the analysis of data on the incidence of coronavirus among Russians vaccinated with both vaccine components between December 5, 2020 and March 31, 2021. Hence, statement 2 is correct.
• Covaxin is an inactivated viral vaccine. This vaccine is developed with Whole-Virion Inactivated Vero Cell-derived technology. They contain inactivated viruses, which cannot infect a person but still can teach the immune system to prepare a defence mechanism against the active virus. Hence, statement 3 is correct.
• Hence, option (b) is correct.

Source: IE