South African mutant Covid strain could be more deadly – after scientists warn Kent variant is 30% more fatal

THE new South African coronavirus strain may be more deadly, scientists say. 

The variant, which is more easily spread, has been detected in 77 coronavirus cases in the UK so far.

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It comes after the shocking announcement that the Kent variant is up to 30 per cent more fatal in Covid patients.

The evidence on the Kent strain has been assessed by scientists on the New and Emerging Respiratory Virus Threats Advisory Group (Nervtag), who feed into the government advisory group SAGE.

Nervtag scientists said today they had done some analysis on data in South Africa, finding “a hint of increased mortality”.

But they cautioned there has not been detailed research into the mortality of the South African variant, as there has been with the Kent one, so they cannot be confident in the finding.

To work out if a new strain is truly more deadly, scientists have to do a “controlled” study, where they control for factors that may skew the results.

Speaking at a virtual Science Media Centre briefing today, Nervtag member Prof John Edmunds, London School of Hygiene & Tropical Medicine, said: “In terms of looking at the other variants, we have done some analysis on the South African variant. 

“There may be a hint of increased mortality. But we haven't been able to control... this is just doing analysis from a long way away.

“First of all, it's just a hint. Secondly, that is just looking at it very crudely, rather than what we've done here in the UK where we have matched people very carefully, with the new strain.

“That's the kind of study that has to be done to determine if there is an increased risk of death associated with the South African or Brazil variants, and that has not been done as far as I am aware. I've seen no data at all along those lines.”

Prof Peter Horby, chair of Nervtag, University of Oxford, said: “Obviously we have very detailed data on our patients in the UK strain, we just don't have access to data in South Africa or Brazil so we have much less clarity about those viruses.”

A total of 77 coronavirus cases caused by the South African variant have been found in the UK - however, these cases were picked up from randomly studying samples, so it could be the case that infections of the variant are much higher.

Nine cases have been blamed on a new variant from Brazil, according to the Health Secretary Matt Hancock.

Another Brazilian variant, detected in Manaus and travelers arriving in Japan, has not been diagnosed in the UK.

The government has attributed sky-high infection rates that led to the third lockdown in part to the new variant first identified in Kent, which is now prevalent across the UK and the rest of the world.

'Pretty solid' evidence the Kent strain is more deadly

The Nervtag scientists said the evidence for the Kent variant causing more deaths was strong, after criticism the Government made that statement on Friday evening with a lack of proof. 

Prof Edmunds said: “I think [the data] is pretty solid.

“I think if we’d have not said something about it, you would be criticizing the government for not saying something about it, and trying to keep this thing swept under the carpet. I do think the government were right to raise it.

“We would like to look at this in more detail, look at other data sets… but we haven't really had time to do that as of yet.

“But it's not as if this result came up overnight - we've been working for weeks on it.

“There is quite a lot of evidence, and the effect is not small.”

Prof Edmunds said the data was “statistically significant”, essentially meaning there is confidence in the findings. 

Uncertainty surrounding the figures comes down to the fact mortality has not been studied in hospital patients.

Researchers have matched patients who have both tested positive for Covid on the same day, and in the same location, with either the original strain or the Kent strain, to study the outcomes for either variant.

Three separate groups of experts advising the Government have looked at the impact of the more contagious Kent variant on mortality.

They have found the Kent variant is 30 per cent more deadly, with results ranging between 10 per cent and 50 per cent.

At Friday night’s press conference, The Prime Minister Boris Johnson told the nation from No10: "In addition to spreading more quickly, it also now appears that there is some evidence that the new variant - the variant that was first identified in London and the south east - may be associated with a higher degree of mortality.”

'Too early' for conclusions, experts say

But top scientists played the risk down; Public Health England's medical director Dr Yvonne Doyle said more work was needed to determine whether it is accurate there is a higher mortality rate.

"There are several investigations going on at the moment. It is not absolutely clear that that will be the case. It is too early to say," she told BBC Radio 4's Today programme 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 this will actually happen."

Prof Horby said on Saturday people needed to put the new data "in perspective".

The Nervtag lead told BBC Breakfast: "If you look at it as a relative change like 30 or 40 per cent then it sounds really bad but a big change in a very small risk takes it from a very small number to a slightly bigger, but still very small number, so for most people the risk is very, very small."

It is thought the Kent variant may be more deadly because it has a biological advantage which makes it easier to bind to cells in the body.

Chief scientific adviser Sir Patrick Vallance said studies were currently going on to work out why the Kent Covid variant might be more deadly.

He told the press conference on Friday: “In terms of why it might be transmitting more readily, people are looking at this in laboratories all over the world for all of these variants.

“It may be that it binds more solidly to the receptor for the virus and gets into cells more easily as a result.

“It may be that it grows more readily in certain cell types. Those are things that people are looking at and more information will come.

“What we can conclude is that there must be some mechanism by which it can actually bind or enter cells somehow.”