Time to watch out for BF.7

Time to watch out for BF.7

Subject : Science & technology

Context : For almost a year now, omicron and its lineages and sub-lineages have dominated the global COVID-19 variant map. This is the first time since the pandemic’s start that a variant of concern and its off springs have circulated for so long.

Concept :

• A new variant of COVID-19 termed BF.7, an alias for B.1.1.529.5.2.1.7, is slowly but surely gaining a foothold in several countries. Most cases for this variant have been reported from Belgium, accounting for 25 per cent of the global share.
• Denmark, Germany and France have recorded 10 per cent each of the global caseload of this variant, according to data from cov-lineages.org, a COVID data repository.
• Its presence has doubled rapidly from just 0.8 per cent to 1.7 per cent in the last two weeks in the US, data from the US Centers for Disease Control and Prevention showed.
• It remains to be seen whether BF.7 will behave any differently in terms of severity or its immunity-evading characteristic. However, it does have changes in its spike protein which may give it a growth advantage, allowing it to infect people even more quickly. Alpha, beta, gamma, delta and omicron were unrelated evolutionary events from the same starting point. But all these recent sub-variants build on omicron.
• Variant-specific boosters offer some hope as countries face a surge in cases as fall and winter inches closer. However, uptake of even the first booster of the original vaccine remains low — at just 31 per cent globally, according to Our World in Data.
• According to the World Health Organisation, a variant of concern translates to a rise in transmissibility, an increase in fatality and a significant decrease in effectiveness of vaccines, therapy and other health measures.
• 275 Emerges as major sublineage in Maharastra
• Since the first case of SARS-CoV-2 in March 2020, India has witnessed three pandemic waves. Delta (B.1.617.2) and its sublineages caused the second wave, and Omicron (B.1.1.529) and its sublineages (BA.1 and BA.2) are driving the third wave.
• After the waning of the third wave, India saw a surge in COVID-19 cases from May 2022. On sequencing, these variants were characterised as BA.2 by Pangolin.
• However, the predominance of BA.2 after the waning of the third COVID wave was unexplainable. Subsequently, the Indian isolates of BA.2 were further classified into sub-lineages BA.2.74, BA.2.75 and BA.2.76.
• Since their designation, these new sub-lineages have already spread to over 40 countries.
• They have acquired additional mutations in their spike protein compared to BA.2. These added mutations, over and above those of the parental BA.2 variant, have raised concerns about their impact on viral pathogenicity, transmissibility, and immune evasion properties of the new variants.

  About Omicron

• The 1.1.529 variant (Omicron) was first reported to WHO from South Africa on 24 November 2021 and the WHO’s Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE) on 26th November 2021 has classified it as Variant of Concern (VoC) in view of large number mutations noted in the variant, some of which may make this mutation more transmissible and have immune escape behavior.