UK’s mutant strain ‘is 40% more deadly’

Scientists warn of ‘realistic possibility’ that it raises risk – as well as spreading more easily

THE new variant of coronavirus sweeping through the country is significantly more deadly, scientists believe.

Boris Johnson warned last night the mutated virus ‘may be associated with a higher degree of mortality’.

Experts believe vaccines will still work against the variant but it may explain why hospitals have suffered so badly in recent weeks.

Sir Patrick Vallance, the Government’s chief scientific adviser, told the Downing Street briefing last night the new variant – known as B117 – is thought to increase mortality by 30 to 40 per cent.

But others have calculated the death risk may be up to 91 per cent.

Ministers were only informed about the development yesterday morning after scientists on the New and Emerging Respiratory Virus Threats Advisory Group (Nervtag), a subcommittee of Sage, discussed the issue on Thursday.

The group concluded there was a ‘realistic possibility’ that the variant resulted in an increased risk of death when compared with the original strain.

Evidence for increased mortality remains thin – Nervtag papers reveal that the term ‘realistic possibility’ is used when scientists are only 40 to 50 per cent confident something is true.

But the decision to reveal the new information just hours after learning of the development is a yardstick of how alarmed ministers are.

The Prime Minister told the Downing Stret briefing: ‘We’ve been informed today that in addition to spreading more quickly it also now appears that there is some evidence that the new variant – first identified in London and the South East – may be associated with a higher degree of mortality.’

The B117 variant first emerged in September and has since spread throughout the country.

According to the Office for National Statistics Covid infection survey published yesterday, 60 per cent of cases in England – and 70 per cent in London – now involve the mutation.

Scientists quickly realised the new variant is up to 70 per cent more transmissible than the original version.

But it was only after they were able to monitor its impact on hospitalisations and deaths for a few weeks that they were able to make any conclusions about lethality.

Sir Patrick said that even now the science is at an early stage.

‘These data are currently uncertain and we don’t have a very good estimate of the precise nature or indeed whether it is an overall increase, but it looks like it is,’ he added.

He said for men in their 60s, the average risk was that for 1,000 who got infected, roughly 10 would be expected to die, but with the new variant it might be 13 or 14. That equates to an increased relative risk of 30 to 40 per cent.

The Nervtag summary document presented to ministers reveals scientists at Exeter University believe the increased death risk could be 91 per cent.

Two studies by Public Health England have put the risk at up to 65 per cent – although a third puts it at zero.

Studies by Imperial College London and the London School of Hygiene and Tropical Medicine puts the additional mortality risk at roughly a third.

Sir Patrick noted that estimates vary

– and stressed some concluded there was no additional risk – but said his best guess was that deaths increase by about 30 to 40 per cent.

He added: ‘The death rate is awful and it’s going to stay, I’m afraid, high for a little while before it starts coming down – that was always what was predicted from the shape of this.’

Nervtag, chaired by Professor Peter Horby of Oxford University, concluded that death rates have not increased among those in hospital.

But evidence suggests it raises the risk of being hospitalised in the first place, driving up the overall death figures.

Labour’s health spokesman Jonathan Ashworth said the news was ‘deeply

‘Data currently uncertain’

‘The death rate is awful’

alarming’. He added: ‘We urge ministers to go further and faster on vaccination roll- out to save lives and introduce proper financial support for those needing to isolate.’

Professor Rowland Kao, of the University of Edinburgh, said last night: ‘It would appear the new variant is also responsible of the increased, unexpectedly high burdens in hospitals seen especially around London.’

Sir Patrick said there was growing evidence vaccines would be effective against the UK variant, but uncertainty over how well they would work against those from South Africa and Brazil.

‘They are definitely of more concern than the one in the UK at the moment, and we need to keep looking at it and studying it very carefully,’ he added.

But he stressed there was no sign that the South African or Brazilian variants had any ‘transmission advantages’ over the UK one so would not necessarily be expected to spread more quickly.