Worrying graphics show just how mutated the newly-emerged Omicron variant is - as scientists around the world scramble to find out if vaccines work against it.
Illustrations released by the Genomics UK Consortium (COG-UK) show that it has a worrying 32 mutations on its spike protein.
By comparison Delta - which tore through the population last winter and has since become the world's dominant strain - has seven.
Experts have said Omicron, which was first identified by scientists in South Africa, is the most mutated Covid variant they have yet encountered.
This morning a spokesman for the UK Health Security Agency told The Mirror that targeted testing is being carried out for the variant.
This means that not every positive PCR test is screened for the new strain.
At the weekend Boris Johnson announced a range of measures aimed at halting Omicron's spread, including compulsory PCR testing for all travellers arriving in the UK from abroad.
Contacts of those identified as having the strain are also required to isolate for 10 days, regardless of whether they have vaccinated.
Officials say it is too early to tell how worried we should be about the variant, with Brits urged to show caution.
The strain has been classified as "of concern" by the World Health Organisation (WHO).
It is feared that Omicron could prove resistant to vaccines because of the number of mutations in its spike protein.
This affects how it responds to antibodies in the immune system, and the way it enters human cells.
This week South African Raquel Viana, Head of Science at one of South Africa's biggest private testing labs, said she had "a sinking feeling" when she discovered the new strain while genetically testing positive swabs in the country.
She told Reuters: "I was quite shocked at what I was seeing. I questioned whether something had gone wrong in the process."
Early indications show most Omicron coronavirus cases are "mild", the World Health Organisation has said.
The official believes there is no evidence to suggest the efficacy of vaccines reduces when battling against the new variant.
The organisation, quoted by Reuters, suggested "most" cases so far examined are not severe.
They cautiously added there is still a lot not yet known about the new strain.
