It’s the news no-one wanted to hear: on Friday evening, the Prime Minister told Brits that the new variant first picked up in the UK might be more deadly than previous versions of the virus.
But within hours, some experts had appeared to play down the claim. It’s also been suggested that even if it is more dangerous, the death rate in the coming months might still end up lower than last spring’s thanks to better treatment.
Let’s take a look at what we know.
How much worse?
Boris Johnson told reporters on Friday that as well as being more easily transmitted, “it also now appears that there is some evidence that the new variant […] may be associated with a higher degree of mortality”.
The chief scientific advisor, Patrick Vallance, said it could be around 30 per cent more deadly.
He gave the example of 1,000 men in their sixties testing positive for the disease. Previously, we would have expected 10 to die – with the new variant, that would now be “13 or 14”.
It seems the issue isn’t that those in hospital with covid are more likely to die – rather that those who catch the new variant are more likely to end up there.
But Professor Vallance added: “I want to stress that there is a lot of uncertainty around these numbers and we need more work to get a precise handle on it”.
‘Too early to say’
And other scientists echoed his caution. The government’s NERVTAG experts say there is a “realistic possibility” that the new variant is linked to more deaths. According to their terminology, that means chances of the theory being correct are currently between 40 and 50 per cent.
Dr Mike Tildesley of the government’s SPI-M expert group said: “I would be wanting to wait for a week or two more, monitoring a little bit more before we draw really strong conclusions about this”.
“I just worry that where we report things pre-emptively where the data are not really particularly strong”, he said.
Dr Yvonne Doyle of Public Health England told the BBC on Saturday: “There is some evidence, but it is very early evidence. It is small numbers of cases and it is far too early to say”.
We heard similar caution from Ian Jones, professor of virology at the University of Reading, who told FactCheck: “it’s not absolutely clear that the variant does cause higher mortality and the only good confirmation will come from a combination of more numbers and some lab experiments that show how the variant could lead to more pathology (and death).”
Dr David Strain, senior clinical lecturer at the University of Exeter, pointed out that the data comes from a sample of 8 per cent of deaths over a short time period.
And Dr Julian Tang, honorary associate professor and clinical virologist at the University of Leicester, notes that the NERVTAG paper uses “relatively low numbers” of cases of the new variant to make its conclusions, so Professor Vallance’s example of the men in their sixties could be subject to “large changes later”.
What about all those life-saving treatments?
It was suggested over the weekend that even if the new variant is more deadly, the death rate in the next few months might still be lower than in the first wave because of advances in treatment.
But the maths behind this is precarious.
Death rates among covid patients have reduced by about 30 per cent since the start of the pandemic – largely thanks to the steroid drug dexamethasone.
If the new variant increases the death rate by 30 per cent, then it risks cancelling out all those gains.
But, as Dr Strain points out, only about half of hospitalised covid patients currently have the new variant, so for now at least, we might still expect a higher proportion of people to survive than did last spring.
(Though of course, we’d still have been better off with no UK variant at all).
And Dr Strain makes an important point about the severity of the disease itself: the new variant is infecting “younger, fitter patients” so “a mortality that was the same would actually reflect a more serious condition” because it would take a stronger virus to kill otherwise healthy people.
The NERVTAG experts attempted to account for this in some of their analyses. The team at Imperial initially estimated that the new variant is 29 per cent more deadly than earlier ones – but this figure rose to 36 per cent when they adjusted for the healthier new patient population. The London School of Hygiene bumped its estimate up from 28 per cent to 35 per cent for similar reasons.
As we’ve found throughout this pandemic, we need more data before we can say anything for certain.