Omicron Sub-Variant BA.2 More Prevalent In India, Says Centre | What Do We Know So Far About The New Subtype

The BA.2 sub-variant of Omicron is more prevalent in India now, the National Centre for Disease Control (NCDC) director said on Thursday at a daily press briefing on the COVID-19 situation in the country.

New Delhi: The BA.2 sub-variant of Omicron is more prevalent in India now, the National Centre for Disease Control (NCDC) director said on Thursday at a daily press briefing on the COVID-19 situation in the country.

The latest variant of COVID-19 called 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 reportedly begun to spread faster.

Earlier, Indian SARS-CoV-2 Consortium on Genomics (INSACOG) said an infectious sub-variant of Omicron BA.2 lineage has been detected in a considerable fraction in India. “BA.2 lineage is a substantial fraction in India and S-gene dropout-based screening is thus likely to give high false negatives. Tests suitable for PCR-based screening applicable to all Omicron lineages have been approved for use”, said the genomics consortium in its bulletin.

The INSACOG has said that while most Omicron cases so far have been asymptomatic or mild, hospitalisations and ICU cases have been increasing in the current wave. The threat level remains unchanged.

“The recently reported B.1.640.2 lineage is being monitored. There is no evidence of rapid spread and while it has features of immune escape, it is currently not a variant of concern,” the bulletin on January 23 read.

Meanwhile, the INSACOG said new COVID variant Omicron has reached in community transmission level in India. “Omicron is now in community transmission stage in India and has become dominant in multiple metros, where new cases have been rising exponentially”, said INSACOG

Concerns over Omicron sub-variant BA.2

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. 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.

Not much information is available if the BA.2 sub-variant of Omicron is a more transmissible strain of COVID.

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.