New Covid-19 variants spreading across the globe, what risk do they pose?

Subject : Science

Context-

2,060 new infections were recorded in the country over the last 24 hours– omicron sub-variants such as the BF.7 and recombinant variants such as XBB are spreading in several countries.

Latest situational report of WHO-

The BA.5 sub-variant of omicron continues to be the dominant one across the globe, accounting for 76.2 per cent of the cases, according to the latest situation report by the World Health Organisation.
In India, BA.4 and BA.5 sub-variants never became the dominant variants.
At present, BA.2.75 continues to cause most of the infections.

New variants across the globe-

New variants scientists are watching out for, In the United States,BQ.1, BQ.1.1, and BF.7 are being monitored as variants of concern because of an increase in cases caused by them.
As per data from the Centre for Disease Control– USA, BQ.1 and BQ.1.1 each account for 5.7 per cent of the total cases, while BF.7accounts for 5.3 per cent.
In the United Kingdom, the BQ.X variant and BF.7 are under the scanner as they gain ground over the dominant BA.5.
According to the UK Health Security Agency, BF.7 accounted for 7.26 per cent of Covid-19 cases and is showing a relative growth advantage of 17.95 per cent over BA.5.
Closer home, recombinant variant XBB– which is a combination of two omicron sublineagesBJ.1 and BA.2.75 – is driving up infections in Singapore, accounting for 54 per cent of the local cases.

New variant in India-

XBB is spreading in India too.
BA.2.75 was the dominant variant in India, accounting for almost 98 per cent of cases till as recently as last week.
However, XBB is on the rise, causing 20 to 30 per cent of infections in some states, like Maharashtra.
The scientist, however, added that the three big labs in Maharashtra, Gujarat, and West Bengal have been sequencing more samples than other parts of the country, and hence newer variants are being identified there.

Risk posed by new variants-

Although these variants are causing a larger share of infections, they are not leading to more hospitalisations and deaths.
Hospitalisation was down 4.4 per cent and deaths 8.5percent in the USA.
United Kingdom, on the other hand, has seen an increase in hospitalisations and deaths in October.
Singapore has also reported an increase in hospitalisation, but the number of severe cases has remained low.
As for India although XBB seems to be more transmissible, there hasn’t been any increase in hospitalisations or deaths.
The emerging variants are becoming more transmissible and better able to escape immunity.
A large chunk of the population now has immunity either through vaccination or infection, so the virus needs to adapt to continue to survive.

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.

The WHO has decided to name the variants after the letters of the Greek alphabet, to avoid the countries that first detected them being stigmatised.