A sub-lineage of the Omicron strain has been formally designated as a “variant under investigation” by the UK Health Security Agency.
Just 53 cases of BA.2 have been detected in the UK up to 10 January, the UKHSA said.
Unlike the original Omicron variant, which accounts for the majority of infections in the UK, BA.2 does not carry a unique mutation that was used as a proxy to first track and compare its early spread against Delta last month.
UKHSA said further analysis will be carried out into the sub-variant.
“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,” said Dr Meera Chand, incident director at the agency.
“Our continued genomic surveillance allows us to detect them and assess whether they are significant.”
BA.2 has been spreading quickly in places like India and the Philippines, and early signs show it is growing in the UK, Germany and Denmark. It’s not clear where the sub-variant first emerged.
There are some indications it may be more transmissible, but experts say there is no conclusive evidence as of yet. Nor is it known whether BA.2 causes more severe disease than the original Omicron variant.
Tom Peacock, a virologist at Imperial College London, speaking to Yahoo News, said the early data “suggest there is no dramatic difference in severity compared to BA.1 [Omicron].
“There is likely to be minimal differences in vaccine effectiveness against BA.1 and BA.2.”
