New coronavirus variant: what do we know?

By James Gallagher
Health and Science Correspondent

A computer generated graphic of the virus in front of red blood cells

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The rapid spread of a new variant of the coronavirus has been blamed for introducing strict fourth-tier mixing rules for millions of people, stricter restrictions on mixing for Christmas in England, Scotland and Wales, as well as other countries where the UK has banned travel.

So how did it go from non-existence to the most common form of the virus in parts of England in just a few months?

The government advisors on new infections have “moderate” confidence

it can transmit better than other variants.

All work is at an early stage, contains great uncertainties and a long list of unanswered questions.

As I wrote earlier, viruses are constantly mutating and it is important to focus the laser on whether the virus is changing its behavior.

Why is this variant cause for concern?

Three things come together, which means that it gets attention:

  • It quickly replaces other versions of the virus
  • It has mutations that affect a part of the virus that is likely to be important
  • Some of these mutations have been shown in the laboratory to increase the virus’ ability to infect cells

All of this together makes a case for a virus that is easier to spread.

However, we are not absolutely certain. New varieties can emerge more frequently if they are in the right place at the right time – for example in London, where until recently there were only second tier restrictions.

However, the justification for Tier 4 restrictions is already in part to reduce the spread of the variant.

“Lab experiments are required, but would you like to wait weeks or months? [to see the results and take action to limit the spread]? Probably not under these circumstances, “said Prof. Nick Loman from the Covid-19 Genomics UK Consortium.

How much faster does it spread?

It was first discovered in September. In November, around a quarter of the cases in London were the new variant. This reached almost two thirds of the cases in mid-December.

You can see how the variant has dominated test results at some centers like the Milton Keynes Lighthouse Laboratory.

Mathematicians used the numbers for the diffusion of different variants to calculate how much edge they might have.

However, it is difficult to tell apart what is due to human behavior and the virus.

The figure mentioned by Prime Minister Boris Johnson said the variant could be up to 70% more transferable. He said this could add 0.4 to the R-number – which indicates whether an epidemic is growing or shrinking.

That 70% figure appeared in a presentation by Dr. Erik Volz from Imperial College London.

During the conversation he said, “It’s really too early to say … but from what we’ve seen so far, it’s growing very quickly, it’s growing faster than [a previous variant] ever grown, but it’s important to keep this in mind. “

There is no “nailed” number for how much more contagious the variant could be. Scientists whose work is not yet public have given me numbers that are both much higher and much lower than 70%.

However, questions remain as to whether it is even more contagious.

“The amount of evidence in the public domain is absolutely insufficient to form a strong or firm opinion on whether the virus really increased transmission,” said Prof. Jonathan Ball, a virologist at the University of Nottingham.

How far has it spread?

The variant is believed to have either occurred in a patient in the UK or was imported from a country with a lower ability to monitor for coronavirus mutations.

The variant can be found across the UK, with the exception of Northern Ireland, but is heavily concentrated in London, the southeast and east of England. Cases elsewhere in the country don’t seem to have worked.

Data from Nextstrain, which has been monitoring the genetic codes of virus samples around the world, suggests cases in Denmark and Australia originated in the UK. The Netherlands have also reported cases.

A similar variant that has emerged in South Africa shares some of the same mutations, but does not appear to be related to this one.

Has that happened before?

The virus, which was first discovered in Wuhan, China, is not the same one that you find in most corners of the world.

The D614G mutation appeared in Europe in February and became the dominant form of the virus worldwide.

Another, called A222V, spread across Europe and was associated with the summer vacation of the people of Spain.

What do we know about the new mutations?

An initial analysis of the new variant was published and identified 17 potentially important changes.

The spike protein has been altered – this is the key that the virus uses to open the door to our body’s cells.

A mutation called N501Y changes the most important part of the tip known as the “receptor binding domain”.

This is where the tip comes into contact with the surface of the body’s cells for the first time. Any changes that make it easier for the virus to get inside the virus are likely to give it an edge.

“It looks and smells like an important adjustment,” said Prof. Loman.

The other mutation – an H69 / V70 deletion in which a small part of the tip is removed – has already occurred several times, even in infected mink.

Work by Prof. Ravi Gupta at the University of Cambridge has shown that this mutation doubles the infectivity in laboratory experiments.

Studies by the same group suggest that the mutation makes antibodies from the blood of survivors less effective at attacking the virus.

Prof. Gupta told me, “It is increasing rapidly, this is what is worrying the government, we are concerned, most scientists are concerned.”

Where does it come from?

The variant is unusually strongly mutated.

The most likely explanation is that the variant occurred in a patient with a weakened immune system who was unable to defeat the virus.

Instead, her body became a breeding ground for the virus to mutate.

Does it make the infection more deadly?

There is no evidence of this, although this needs to be monitored.

However, increasing the transmission would be enough to cause problems for hospitals.

If the new variant means more people are infected more quickly, this in turn would lead to more people needing hospital treatment.

Will the vaccines work against the new variant?

Almost certainly yes, or at least for now.

All three leading vaccines develop an immune response against the spike that is present, which is why the question arises.

Vaccines train the immune system to attack different parts of the virus. Even though part of the top has mutated, the vaccines should still work.

“But if we allow more mutations to be added, you will worry,” said Prof. Gupta.

“This virus may be on its way to escape the vaccine. It has taken the first steps in that direction.”

The vaccine leak occurs when the virus changes, so it evades the full effects of the vaccine and continues to infect people.

This is possibly the most worrying element of what is happening to the virus.

This variant is just the latest, showing that the virus continues to adapt as it infects more and more of us.

A presentation by Prof. David Robertson of the University of Glasgow on Friday concluded: “The virus will likely be able to produce vaccine mutants.”

That would put us in a similar situation to the flu, where vaccines need to be updated regularly. Fortunately, the vaccines we have are very easy to tweak.

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