The Kent coronavirus variant is more deadly than original strains of the virus, another study has claimed.
Researchers analysed the lethality of the highly transmissible strain which is now the dominant type circulating in the UK and found it was worse than earlier variants.
Data from around 55,000 Brits revealed the variant, known as B117, likely increased the risk of death after infection by 64 per cent and potentially as much as doubled it.
Experts said this would equate to the virus killing around 0.41 per cent of everyone it infected in the general public — or one in 250 people.
For comparison, the original Covid strain had a lethality rate of around 0.25 per cent, British experts concluded.
The research, carried out by academics at the universities of Exeter, Bristol, Warwick and Lancaster, was published in the British Medical Journal.
It comes after No10’s top scientific advisers spooked the nation in January when they warned the variant, which first emerged in Kent in September, was up to 30 per cent deadlier than older versions.
Boris Johnson, Sir Patrick Vallance and Professor Chris Whitty told a Downing Street press conference that hospital data suggested the variant could increase the risk of death for a man his 60s from 1 per cent to 1.3 per cent.
But confusion mounted following the claims, with a senior Public Health England boss playing down the fears and insisted it was not ‘absolutely clear’ if it was any deadlier.
The data used to present the findings to the public contained 10 different studies sent to SAGE, with the lethality estimates varied vastly and one study even found the strain was less deadly than the older version.
The new study bolsters the claims, with experts saying the findings mean relaxing lockdown too soon would be a ‘reckless gamble’.
Epidemiologists from the Universities of Exeter and Bristol said the data suggests the variant is associated with a significantly higher mortality rate among adults diagnosed in the community compared with previously circulating strains.
Robert Challen, from the University of Exeter, lead author of the study, said: ‘In the community, death from Covid-19 is still a rare event, but the B117 variant raises the risk.
‘Coupled with its ability to spread rapidly, this makes B117 a threat that should be taken seriously.’
Researchers looked at death rates among people infected with the new variant and those infected with other strains.
They found that the variant first detected in Kent led to 227 deaths in a sample of 54,906 patients – compared with 141 among the same number of closely matched patients who had the previous strains.
The variant is more transmissible and is thought to have contributed towards the rapid increase in cases before new lockdown rules were introduced across the UK.
According to the study, published in the British Medical Journal, the higher transmissibility of the Kent strain meant that more people who would previously have been considered low risk were admitted to hospital with the newer variant.
Leon Danon, from the University of Bristol, senior author of the study, said: ‘We focused our analysis on cases that occurred between November 2020 and January 2021, when both the old variants and the new variant were present in the UK.
‘This meant we were able to maximise the number of ‘matches’ and reduce the impact of other biases. Subsequent analyses have confirmed our results.
‘Sars-CoV-2 appears able to mutate quickly, and there is a real concern that other variants will arise with resistance to rapidly rolled out vaccines.
‘Monitoring for new variants as they arise, measuring their characteristics and acting appropriately needs to be a key part of the public health response in the future.’
Ellen Brooks-Pollock, from the University of Bristol, said: ‘It was fortunate the mutation happened in a part of the genome covered by routine testing.
‘Future mutations could arise and spread unchecked.’
In January a paper from the New And Emerging Respiratory Virus Threats Advisory Group (Nervtag) said there was a ‘realistic possibility’ that the variant was associated with an increased risk of death.
But scientists warned there was a lot of uncertainty around the data.
Mutations of the virus have raised concerns about whether vaccines would be effective against the new strains, including the now-dominant Kent strain.
But research suggests the Pfizer jab is just as effective against the Kent variant of coronavirus as it was against the original pandemic strain, while other data indicates the Oxford/AstraZeneca jab has a similar efficacy against the variant.