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A fast-spreading variant of Sars-CoV-2, the virus that causes Covid-19, forced Boris Johnson to scale back his government’s “Christmas bubble” plans for England, including a “stay at home” order that it covers London and much of the south and east of England.
These additional restrictions for millions of people may need to stay in place for several months until vaccines are rolled out across the UK. But what can scientists tell us so far about this variant? Should we be concerned?
What do we know about this new variant?
All viruses, and indeed coronaviruses, mutate all the time, so it is not unexpected that this new variant has emerged.
Dr Muge Cevik, a member of the New and Emerging Respiratory Virus Threat Advisory Group (Nervtag), said that more than 4,000 Sars-Cov-2 mutations have been observed so far, of which perhaps a handful appear to have some. importance.
England’s chief medical officer Chris Whitty said the new variant discovered in the South East could be up to 70% more transmissible and could increase the R-value by 0.4 or more. Given the data so far, it does not appear to increase the risk of severe disease or the death rate.
In a Nervtag summary published Sunday, the experts wrote that they had “moderate confidence” that the variant demonstrated a substantial increase in transmissibility compared to other variants.
However, they cautioned that the data was preliminary and based on models. Results depend on the quality and quantity of data you provide, Cevik said. “Right now, we can’t establish a causal relationship, it’s just an association effect,” he said.
The data accumulated so far is consistent with the understanding that the variant is more infectious or capable of spreading more efficiently, but we have no laboratory confirmation of that or any idea why it is spreading faster, said Stuart Neil. , a professor of virology at King’s College, London.
The variant was associated with 10% to 15% of cases in certain areas a few weeks ago, but last week it jumped to about 60% of cases in London, he said.
What do we not know?
What worries scientists most at the moment are changes in the variant’s spike protein, the part of the virus that allows it to infiltrate cells in the lungs, throat, and nasal cavity by interacting with a receptor called ACE. -2, Neil said.
The mutation in the spike protein may enhance the virus’s ability to interact with ACE-2, giving it a growth advantage, he said. On the other hand, the spike protein is the part of the virus that vaccines are designed to develop antibodies against, so this mutation could prevent the vaccine from doing its job. “It’s something that really needs to be monitored,” he said.
Another big concern is that it is not yet clear how many factors have been driving the broadcast in recent weeks, Cevik said. The variant is likely to have influenced transmissibility, but high rates of transmission have also been observed in areas with greater restrictions.
“Sometimes it comes back to the uncomfortable fact of social inequalities. The locks have limited effects on people who cannot work from home, ”he said.
Should restrictions be tightened if there are so many unknowns?
It’s always difficult to make decisions based on limited data, but given what we know so far about this variant, experts say it’s important to err on the side of caution.
“We may see trends, but they may not materialize later. In this current situation, I think … it’s probably too early to tell. But, it was a bit difficult not to act on it, especially since there was a plan for families to get together over Christmas, “said Cevik.
Professor Andrew Hayward, Professor of Infectious Disease Epidemiology at University College London and a member of the Scientific Advisory Group for Emergencies (Sage), said: “London and the South East are far ahead, but it only took them a week or two to pass really from relatively low levels to very high levels, so I feel like it will be inevitable that more stringent restrictions will be needed across the country.
“As usual, as always, actually, it’s better to go harder earlier if you want to avoid the most deaths.”
He said the stricter restrictions were an effort to reduce transmission until as many vulnerable people as possible could be protected.
“That would give us many more weeks in which we could vaccinate people and save … in my opinion, tens of thousands of lives.”
Is the orientation of social distancing sufficient if the variant is more transmissible?
We don’t understand enough about the variant to know its impact on existing orientation in terms of social distancing and wearing masks, experts say.
Catherine Noakes, Professor of Environmental Engineering for Buildings at the University of Leeds and a Sage Fellow, said: “I think a lot of people are pretty relaxed right now about distancing, and we have to remember that the risk increases the closer you get. tosomeone.
“We need to take all the measures we can to reduce our potential exposure to it … where interactions are necessary, that we are really rigorous in applying the measures that we have.”
Should schools reopen in January, given what we know about the variant?
It is a huge advantage that schools are not open at this time, Hayward said. “I think one of the questions for me is is it really sensible to go back in early January even with a staggered start to plan for all students to go back to school.
Neil said: “The scientist in me says that the most effective way to block the transmission of the virus is to limit any contact between anyone who can transmit the virus. But there’s the other half of me, the parent, who sees how potentially damaging the effect of limiting children’s development and education by closing schools can have.
“My feeling is that the last thing I should possibly consider is closing schools. However, I would recommend a much more aggressive prospective evaluation of staff in schools. “
Should we be worried?
“I think we already have enough information to know that this variant has the potential to cause a new, larger epidemic, worse than we had previously predicted,” Hayward said, noting that an increase in transmissibility, even with the same mortality rate , would lead to many more deaths.
Noakes said: “I think over the next several months we are going to balance the restrictions … until we have enough vaccine coverage to be able to relax a bit.”
