With around 1,14,475 active cases of COVID-19 in India, the sudden surge in the cases has made scientists express concern over the spread of Omicron’s sub-variant BA.2.75 which may be the reason behind the sudden surge. The sub-variant has an 18 per cent growth advantage over others of its kind.

Scientists across the world have flagged the emergence of a new coronavirus variant in India, the BA.2.75, which is said to be cropping up increasingly in samples, and may have an increased ability to infect people who have been infected before, as well as those who are vaccinated. 

BA.2.75 is a sub-lineage of the Omicron variant. Sub-lineages of Omicron have become the dominant variants circulating across the globe, with new mutations continuously evolving. 

At least 23 samples of the BA.2.75 variant have been detected in India so far, in Maharashtra, Karnataka and Jammu & Kashmir, according to the data uploaded on Nextstrain, an open-source platform of genomic data. 

Worldwide, just about 37 samples of the variant have been detected, including in Australia, Germany, Canada and New Zealand, according to the Nextstrain data. 

There has been no official communication about the variant from the Indian government, or the Indian SARS-CoV-2 Genomics Consortium (INSACOG), a genomic surveillance agency functioning under the health ministry. However, independent scientists from many parts of the world have flagged BA.2.75 on various online platforms, pointing out that the accumulation of different mutations on the spike protein of this variant is a cause for concern. 

As per reports, the sub-variant was a dominant strain earlier this year and was one of the most commonly detected sub-variant in recent results of genome sequencing.

The medical experts have labelled the three sub-variants of Omicron BA.2.74, BA.2.75 and BA.2.76, and flagged subvariant BA.2.75 for special observation.

Thomas Peacock, a scientist at Imperial College London, wrote in a Twitter thread, “Surveillance-minded folks- worth keeping a close eye on BA.2.75 that has a lot of spike mutations, probable second-generation variant, apparent rapid growth and wide geographical spread.”

As per reports, 10 states have reported BA.2.75 variants including Delhi and Maharashtra. However, the Health Ministry is yet to make an official statement regarding the detection of the sub-variant in the country. Also, around 85 sequences of the sub-variant from eight countries including India have been reported.

As per reports, the BA.2.75 sub-variant has shown more than 16 new mutations. Most of the mutations have occurred in the spike region.

The Bloom Lab at the Fred Hutch research institute in the US tweeted, flagging two mutations as key: G446S and R493Q.

The lab further pointed out that the G446S is one of the most potent sites of escape from antibodies elicited by current vaccines. This means that mutations in the site can result in the virus’ increased capability to dodge antibodies and attach itself better to human cells. This would further mean that the virus has increased capability to infect people who have been infected before, as well as those who have been vaccinated.

Dr Shay Fleishon of the Central Virology Laboratory at Sheba Medical Centre in Tel Hashomer (Israel) observed that the sub-variant is showing behaviour that is different from its other second-generation counterparts.

The medical expert explained that the sub-variant is the first of a second-generation type that has spread across different geographies. He said that whether BA.2.75 will succeed in initiating a wave or not, its growth has shown that even second-generation variants can get better with time.

Dr Rajesh Karyakarte, Vice Dean and Head of Department of Microbiology in BJ Government Medical College (Pune) tweeted in June saying that BA.2 and BA.2.38 are still the dominant lineages. He also said that as per a clinical study, BA.4 and BA.5 show no signs of hospitalization and intensive health care.

As of now, the sub-variant BA.2.75 is competing with other BA.2 sub-lineages now.

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