The new strain of coronavirus is at least 30 per cent deadlier than the original disease, leading to significantly higher deaths in Britain, two leading scientists have concluded.
Whereas one in 55 people who tested positive for Covid-19 in the first wave died, now at least one in 40 is dying, according to a medical paper seen by The National.
The findings could have significant political fallout, with countries across Europe already under pressure to shut their borders to travellers from Britain.
British Prime Minister Boris Johnson corroborated these findings at Friday's Covid press briefing. He said the data could explain why the health service has come under intense pressure in recent weeks.
"There is some evidence the new variant...may be associated with a higher degree of mortality," he said.
"It is largely the impact of this new variant that means the NHS is under so much intense pressure."
He announced that a further 1,401 Covid deaths had been recorded in the past 24 hours, along with another 40,261 cases.
The report, titled Abrupt Increase in the UK Coronavirus Death-case Ratio in December 2020, was compiled in the past week by Professor Sir David Wallace and Prof Graeme Ackland, who are among Britain's most respected computer modellers.
They studied infection and fatality figures since early December, when the new variant began to dominate testing results in some areas, and have suggested that not only is it more infectious but it kills more people.
There is now a possibility that Britain's death toll could double to 200,000, Prof Ackland told The National. "We might get out of this pandemic with 140,000 deaths but if something else happens, if there's a worse variant, or our fears about the new variant being deadlier are confirmed, then it might go to 200,000 deaths," he said.
Public Health England previously said the mutant strain had the same mortality rate as the original Covid, but slow and skewed reporting of deaths and infections over the Christmas period may have hidden that the new strain is deadlier.
“We have shown that the relationship between positive tests and subsequent deaths in the UK changed significantly around early December,” the mathematicians said.
In a worrying conclusion for senior government figures and medical staff, the paper states that the increased number of cases-to-fatality rate suggests that the new mutation VOC [Variant of Concern] is the “possible causation”.
Sir David and Prof Ackland wrote: “We can identify several possibilities. One interpretation would be that the new variant of the coronavirus produces a more severe infection as well as being more transmissible.”
However, the pair, who have rapidly published their findings, said there was “currently no clinical evidence” to support their arguments and the R rate in the UK has fallen sharply since last week, suggesting the lockdown is having an impact on spread of the virus.
Case rate drops but 100,000 Covid deaths milestone looms
The R, which refers to the number of people that an infected person will pass Covid-19 on to, fell to between 0.8 and 1 across the UK, according to the Science and the Scientific Advisory Group for Emergencies (SAGE) on Friday. It had stood at 1.2 to 1.3.
Despite this, Britain’s significantly high number of fatalities – with an average 1,220 deaths a day over the past week – is expected to hit 100,000 early next week.
Many countries are now considering blocking all travel from Britain as a result of the variant.
With Germany just crossing the threshold of 50,000 deaths, Chancellor Angela Merkel on Thursday referred to the “British virus”, suggesting its impact might mean a longer and harder lockdown. “We know the British virus is here, any easing strategy has to be done very carefully,” she said.
The scientists' paper examined the reason for the number of deaths since December that had been “higher than expected from the number of positive tests”.
The paper said: “A higher morbidity for the VOC [Variant of Concern] is one among many possible reasons. Its appearance at a significant level in the south-east in December matches the timing of the increase in expected deaths. This increase is delayed in regions such as Yorkshire where the VOC arrived later.”
However, the latest data from the Office of National Statistics on Friday shows that regions outside the south-east are now experiencing higher infection rates from the new strain.
The paper cited top statistician David Spiegelhalter, whose previous figure of one death to every 55 positive Covid tests had been accepted as accurate, but the paper says that ratio is no longer viable.
“This relationship begins to fail in December, with unexpectedly high death rates. This may be correlated in time and region with the emergence of the Variant of Concern (VOC) B117,” it said.
“Throughout October and November 2020, deaths in England are well described as 1/55th of detected cases from 12 days previously. After that, the relationship no longer holds and deaths are significantly higher.”
In reference to London and the south-east of England, where the strain first emerged, it stated: "This is especially true in regions affected by the VOC B117. In early December, some new factor emerged to increase the case-fatality rate in the UK."
Are younger people dying from the new variant?
While it is currently unclear whether younger people are dying from the virus there is evidence for significantly higher numbers of under 40s contracting it, possibly after gathering over the Christmas period. “UK data was highly skewed by underreporting over Christmas and New Year,” the paper said.
The paper has been submitted to the Medical Archive for peer review, but has already been read by several experts, the authors said.