The recent upsurge in Covid-19 cases in China has bolstered concern among global health experts due to the role of the BF.7 sub-variant of Omicron in driving infections. As a significant strain of the virus, it is essential to understand the characteristics of the BF.7 variant and its impact on the pandemic’s trajectory.
Understanding the BF.7 Variant of Coronavirus
Dubbed BA.5.2.1.7 or more commonly BF.7, this sub-variant of Omicron is currently predominant in China. The virus has been circulating for over a year, and there are around 500 Omicron sub-variants globally.
BF.7, which has evolved from the BA.5 sub-variant, is not unique to China. In fact, in October 2022, it accounted for over 5% of cases in the US and approximately 7% in the UK. The process in which viruses mutate generates lineages and sub-lineages – similar to a tree’s main trunk sprouting branches and sub-branches.
Scientists found that BF.7 presents a 4.4-fold higher neutralisation resistance compared to the original D614G variant. This indicates that antibodies from vaccinations or previous infections are less successful at destroying the BF.7 variant in lab settings, compared to the original virus first identified in Wuhan in 2020. A high neutralisation resistance suggests a greater likelihood of the variant spreading widely in a population and supplanting other variants.
The Birth of New Variants
When a virus reproduces, it occasionally fails to produce an exact genetic duplicate of itself. Consequently, over time, the virus may begin to exhibit minor differences in its genetic structure. These alterations in the viral genetic sequence are referred to as mutations.
Viruses with new mutations are often identified as variants. They can vary in one or more mutations. When a new variant showcases unique functional attributes compared to the original virus and becomes firmly established within a population group, it is occasionally labelled as a new strain of the virus. However, it’s essential to note that while all strains fall under variants, not all variants can be classified as strains.
Understanding Vaccine Platforms: Examining Previous UPSC Civil Services Examination Questions
The Union Public Service Commission (UPSC) Civil Services Examination often tests the understanding of concepts related to the Covid-19 pandemic. For instance, a 2022 question examined understanding of different vaccine platforms used for Covid-19 immunisation as follows:
The question requested candidates to identify correct statements among the following:
1. The Serum Institute of India developed Covishield using an mRNA platform.
2. Sputnik V vaccine employs a vector-based platform.
3. Covaxin is an inactivated pathogen-based vaccine.
The correct answer was statements 2 and 3. This was because Covishield utilises a recombinant, replication-deficient chimpanzee adenovirus vector encoding the SARS-CoV-2 Spike (S) glycoprotein, rather than an mRNA platform. On the other hand, Sputnik V, which has been approved in 71 countries, leverages a human adenovirus vector platform. Similarly, Covaxin is an inactivated viral vaccine developed with Whole-Virion Inactivated Vero Cell-derived technology.
