LONDON, Jan. 21 (Xinhua) -- A new form of Omicron named BA.2 has been designated a "variant under investigation," with 426 cases of the Omicron variant sub-lineage confirmed in the United Kingdom (UK), the UK Health Security Agency (UKHSA) said Friday.
"Overall, the original Omicron lineage, BA.1, is dominant in the UK and the proportion of BA.2 cases is currently low," with the earliest dated Dec. 6, 2021, the agency said in a statement.
In total, 40 countries have uploaded 8,040 BA.2 sequences to the Global Initiative on Sharing All Influenza Data (GISAID) since Nov. 17. At this point, it is not possible to determine where the sub-lineage may have originated, it added.
The first sequences were submitted from the Philippines, and most samples have been uploaded from Denmark (6,411), while other countries that have uploaded more than 100 samples are India (530), Sweden (181), and Singapore (127), according to the agency.
Meera Chand, incident director at the agency, said new mutations are "expected" as the pandemic continues. "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."
Official figures on Friday showed the UK added 95,787 COVID-19 cases in the latest 24 hours, bringing its total caseload to 15,709,059, and 288 more deaths, taking the national death toll to 153,490.
More than 90 percent of people aged 12 and above in the UK have had their first dose of vaccine, more than 83 percent have taken both shots, and more than 63 percent have received booster jabs.