LONDON- The UK Health Security Agency on Friday said it had designated a sub-lineage of the dominant and highly transmissible Omicron coronavirus variant as a variant under investigation.

BA.2, which does not have the specific mutation seen with Omicron that can be used as a proxy to easily distinguish it from Delta, is being investigated but has not been designated a Variant Of Concern.

"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," Dr Meera Chand, incident director at the UKHSA, said.

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

(Reporting by Alistair Smout. Editing by Andrew MacAskill) ((alistair.smout@thomsonreuters.com; +44 207 542 7064; Reuters Messaging: alistair.smout.thomsonreuters.com@reuters.net))