UK Health Security Agency (UKSHA) said on Friday that 28 COVID-19 cases linked to the highly mutated variant BA.2.86 had been identified at a care home in Norfolk.

Six others have been reported elsewhere.

The Omicron offshoot carries more than 35 mutations in key portions of the virus compared with XBB.1.5, the dominant variant through most of 2023, a number roughly on par with the Omicron variant that caused record infections.

Of the 34 confirmed cases identified as of Sept. 4, five patients were hospitalised and no deaths had been linked to the new emerging variant.

Moderna (MRNA.O) and rival Pfizer (PFE.N) said on Wednesday their updated COVID-19 vaccines generated strong responses in testing against the BA.2.86 subvariant.

BA.2.86 was first spotted in Denmark on July 24. It has since been detected in other symptomatic patients, in routine airport screening, and in wastewater samples in countries like Switzerland and South Africa in addition to Israel, Denmark, and the U.S.

Based on the new data, it is early to draw any conclusions about the behaviour of BA.2.86 in the wider UK population, but the variant may be sufficiently transmissible in close contact setting, said the agency.

“It is clear that there is some degree of widespread community transmission, both in the UK and globally, and we are working to ascertain the full extent of this”, said Renu Bindra, incident director, UKHSA.UK