Indore lab detects 21 COVID-19 cases of Omicron sub-variant BA.2; is new 'stealth Omicron' more transmissible?

Twenty-one COVID-19 cases caused by the Omicron variant's sub-lineage known as BA.2 have been found in tests conducted over the past 18 days in the laboratory of a private medical institute in Madhya Pradesh's Indore.

Those infected with this sub-lineage of Omicron variant include six children, an official from the private facility said on Monday.

Since January 6, a total of 21 cases of BA.2 sub-lineage of the Omicron variant have been found during tests conducted in our Molecular Virology Diagnostic and Research Lab, which is recognized by the Centre, Vinod Bhandari, founder chairman of Sri Aurobindo Institute of Medical Sciences (SAIMS) told PTI.

"Lung involvement ranging from 1 per cent to 50 per cent was observed in six out of 21 patients of this Omicron sub-lineage. Three patients are still hospitalized, while 18 have been discharged. Of the 21, a total of 15 adults have taken both doses of the COVID-19 vaccine," Bhandari informed.

Indore, the worst coronavirus-hit district in Madhya Pradesh, has a caseload of 1,86,216, including 1,409 deaths.

Even as Omicron has been showing signs of peaking, some European countries are seeing the rise of Omicron subvariant BA.2, sparking concern among the scientific community.

The subvariant BA.2, dubbed with the moniker "Stealth Omicron," appears to be gaining ground in certain parts of the world, including Denmark and the UK, Euronews reported.

It is rapidly outpacing other Omicron subvariants, and sparking fears that a more transmissible strain of Covid is actively spreading through the community.

The UK Health Security Agency, recently, designated the BA.2 as a variant under investigation.

"53 sequences of the BA.2 sub-lineage of Omicron had been identified in the United Kingdom," it said in a statement.

"This sub-lineage, which was designated by Pangolin on December 6, does not have the spike gene deletion at 69-70 that causes S-gene target failure (SGTF), which has previously been used as a proxy to detect cases of Omicron.

'UKHSA are continuing to monitor data on the BA.2 sub-lineage closely," the statement said.

"It is the nature of viruses to evolve and mutate, so it's to be expected that we will continue to see new variants emerge as the pandemic goes on," Dr Meera Chand, Incident Director of the UKHSA, was quoted as saying.

"Our continued genomic surveillance allows us to detect them and assess whether they are significant," she added.

Omicron, which is also referred to as B.1.1.529, has three main substrains, BA.1, BA.2, and BA.3, according to the World Health Organisation (WHO).

Up until now, it has been BA.1 that has been dominating with the WHO estimating it makes up a large majority of all Omicron cases.

However, in some places, the BA.2 has begun to spread faster, the report said.

In Denmark, it now makes up almost half of all Omicron cases. Other countries such as Norway and Sweden are also experiencing an increase in BA.2 cases, although not to the same extent.

"Initial analysis shows no differences in hospitalisations for BA.2 compared to BA.1," said Denmark's Statens Serum Institut, a government-run infectious disease research centre, in a statement.

"Analyses regarding infectiousness and vaccine efficiency etc. are ongoing, including attempts to cultivate BA.2 in order to perform antibody neutralisation studies."

The institute stated that vaccines likely have an effect against severe illness from BA.2 infection.

With agencies inputs