‘Very thin evidence’ on new variant of coronavirus, say scientists after Matt Hancock’s announcement

Scientists monitoring the new coronavirus variant have said they currently have “very thin evidence” on the strain, after Matt Hancock made a national announcement suggesting it may be behind rising cases in southeast England.

The health secretary used a Downing Street press conference on Monday to warn of a rise in new cases and to move Greater London and parts of Essex and Hertfordshire into the highest tier of restrictions, and risked further alarming the public by announcing the existence of a new strain and suggesting it “may be associated with the faster spread in some areas”.

But the following day, Professor Sharon Peacock, director of the Covid-19 Genomics UK (COG UK) consortium – which identified the new set of mutations in September – said: “We are still dealing with very thin evidence at the moment about this variant.”

Her COG-UK colleague Nick Loman rejected the idea of tightening Christmas restrictions based on the variant’s discovery, saying: “You make those sort of decisions based on the growth rate of the virus, you make it based on whether cases are going up or going down and the predicted R. 

“You don’t make it on the basis of whether there’s a variant or not, particularly one where we’re at the very early stages of characterising its biological importance.”

Asked during a Science Media Centre briefing why the new variant had been so heavily publicised, Prof Loman said there were two main reasons for concern.

“The first is, it’s quite strongly frequency-associated with the areas of the country where we’re seeing a growth in the numbers of coronavirus,” he said, adding: “This is a correlation, and by no means can we ascertain causation simply from the genomic data, however it is quite a striking growth in that variant – much more than we would see typically in our surveillance so far.”

“The second line of evidence that makes this concerning are simply the sheer number of the mutations which make up this variant – quite a significantly larger number than we would normally expect to see, for reasons unknown, and the characteristics of some of those mutations.”

Prof Loman said there were a “striking” 17 mutations in the new variant – compared with a typical discovery of one or two mutations per new strain. 

“Quite a number of those” are found within the spike protein used to infect human cells, he added.

Prof Loman said that “initial modelling has shown that this [variant] is growing faster than” the strain which first originated in Spanish farmers, spread to the UK in the summer and is now the UK’s “dominant strain”.

“And we don't have that same epidemiological link with a large number of importations” he said, referring to the way the Spanish variant arrived in the UK. “We've not seen that, it's not quite the same idea, which does make you wonder exactly what's going on.”

He added: “None of those things are smoking guns, none of those things are causation, and I think as we’ve been careful to say, all of these things need careful lab experiments to determine whether any of them are important. However, I think there is a sufficient amount of circumstantial evidence … to really think this is something urgent that needs following up with lab work.”

The new variant – named “VUI – 202012/01” – was first identified in September by COG-UK, a government-backed consortium of scientists analysing genome data from some 140,000 coronavirus patients, partly to track mutations.

Prof Loman, of the University of Birmingham, suggested it was “ground-breaking” for scientists to be able to identify a variant’s spread and prevalence in almost real-time, as opposed to retrospectively.

He said there was no evidence to suggest it had come from another country and remarked it “does sort of seem to have come out of nowhere, and then we have a long gap between the first cases that we saw of this variant, which was late September, and what happened before that – a long, unexplained gap”.

There are “very few examples of this variant in other countries at the moment, so it’s really sort of a UK phenomenon,” Prof Loman added.

Professor Tom Connor, of Cardiff University, added that “the observation of the increase over time and results that came initially from modelling [were] so stark that this is something that seemed a bit out of the ordinary in terms of our experience”. 

Referring to whether it was appropriate for the government to announce it on Monday, he said: “There is a question of – ‘is this the sort of thing that you keep under wraps and do stuff on and then it becomes a nasty surprise later on?’ 

“Or do you push it out into the open, share it transparently, and let people understand what’s happening?

“Clearly the government’s taken its own decision on that, but the way we operate in [COG-UK] is we share all of our data freely on the internet, so all of the sequence data is made available to everybody. So actually if people had been looking at our data and analysing it, they would have spotted this increase in our data anyway, and drawn their own conclusions.”

Judith Breuer, of University College London, said that while COG-UK has data to suggest that the new variant has increased in numbers – which scientists think could due to changes in transmission – "we don’t know, and changes in transmission can be due to anything.

“It can be due to more mixing, it could be due to the virus – we don't know," she added.

As stressed by the health secretary, Prof Breuer also said there was “absolutely no data to show anything related to disease severity” and “no data to suggest that this variant is evading immunity in the population or is behaving any differently to the other variants”.

And Prof Loman said it was “very unlikely these mutations are in any way a response to vaccination”, adding: “Mutations that we observe are going to be really important when we do have a large number of doses of the vaccine administered. 

“But there’s nothing about this that is innately worrying relating to the vaccine that’s currently being administered.”