The rapid rise in the mutant variant has seen a surge in Covid-19 cases and hospitalisations and is behind the new Tier 4 restrictions - with Boris Johnson set to update the public further on Monday, December 21.
Where has the new strain of Covid come from?
The new strain's scientific name is VUI 2020/01, with VUI standing for Variant Under Investigation.
Essentially, the mutant strain's origins are still being probed by Public Health England laboratories at Porton Down, Wiltshire.
With no concrete evidence so far explaining how and where it comes from, it can only be assumed to have emerged in England — because that was where most of the known cases were originally reported.
Scientists believe it mutated within a Covid patient's body.
The new variant appears to be prominent in and around the south of England.
Up to 9 December, the mutated virus accounted for:
- South East: 43 per cent of cases and 28 per cent of hospitalisations
- East: 59 per cent of cases and 38 per cent of hospitalisations
- London: 62 per cent of cases and 34 per cent of hospitalisations
In contrast, the new strain is linked to just five per cent of recent cases in Yorkshire.
Case rates across the UK increased by more than 50 per cent between November 29 and December 13.
The new strain is believed to be able to increase the country’s R rate - which is currently estimated to be between 1.1 and 1.2 - by 0.4 per cent.
Meanwhile, the new strain has been detected in Australia, Denmark, Gibraltar and Holland.
Why is the new strain of Covid more contagious?
The new Covid strain is said to be around 70 per cent more infectious than its original form and has sparked rocketing case numbers across London and the south east.
The number of new UK infections on Sunday, December 20 — the date the Tier 4 lockdown came into force — was at an all-time high for recorded cases and was nearly double the 18,447 cases reported the week before.
Why is the new strain spreading faster?
Porton Down scientists said the new strain includes a mutation in the spike protein that may make the virus more infectious.
As he announced the new Tier 4 measures, Prime Minister Boris Johnson said: "Without action the evidence suggests that infections would soar, hospitals would become overwhelmed and many thousands more would lose their lives.
"Yes Christmas this year will be different, very different.
"We're sacrificing the chance to see our loved ones this Christmas so that we have a better chance of protecting their lives, so that we can see them at future Christmases."