• BA.2 subvariant of omicron is spreading quickly
  • It is slowly replacing the BA.1 sub-strain in India
  • UK Health Security Agency is investigating the BA.2 sub-variant

After spreading in 40 countries, including the United Kingdom, India and Demark, the BA.2 subvariant of omicron has now been detected in the United States.

Health officials announced Monday that the variant, commonly called the "stealth Omicron," has been detected in Washington.

According to the World Health Organisation, the omicron variant of coronavirus has three sub-strains — BA.1, BA.2, and BA.3. While the BA.1 sub-strain is currently dominant among the omicron infections reported across the world, the BA.2 sub-strain is spreading quickly and has been detected in 40 countries since Nov. 17, 2021.

The UK Health Security Agency announced last week that it was investigating the BA.2 sub-variant.

"There is still uncertainty around the significance of the changes to the viral genome, and further analyses will now be undertaken," the agency said in a statement.

The Indian SARS-CoV-2 Genomics also confirmed that the BA.2 sub-variant is slowly replacing the BA.1 sub-strain 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," the organization further said.

Early analysis has shown that the BA.2 is more transmissible than the BA.1 sub-strain. However, scientists haven’t been able to spot any significant difference between the two strains.

"So far, there is insufficient evidence to determine whether BA.2 causes more severe illness than Omicron BA.1, but data is limited and UKHSA continues to investigate," Dr. Meera Chand, COVID-19 incident director at UKHSA, noted.

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

Meanwhile, the sub-variant is being called "stealth omicron" by scientists as "it lacks the deletion that allows it to be picked up by PCR tests," Sunit K Singh, Professor of Molecular Immunology and Virology, Institute of Medical Sciences, Banaras Hindu University, told India Today.

"The BA.2 lineage lacks deletion. So, the S gene target failure is not seen in BA.2 which was seen in BA.1 (original omicron). Most of the monoclonal antibodies are not effective against Omicron due to many mutations in their spike. Of course, there might be more infections as already being seen but I do not see any possibility of more severity. Things might be more or less the same as prevailing in today's scene, but people should get vaccinated and take precautionary measures," he added.

WHO chief Tedros Adhanom Ghebreyesus says the Omicron variant is killing people and overwhelming hospitals
WHO chief Tedros Adhanom Ghebreyesus says the Omicron variant is killing people and overwhelming hospitals AFP / Justin TALLIS