EXPLANATOR: Britain’s new variant of the coronavirus: How worrisome is it?

A new variant of the SARS-CoV-2 pandemic coronavirus is spreading rapidly in Britain and is causing high levels of concern among its European neighbors, some of whom have cut transport links.

The strain, which some experts refer to as the B.1.1.7 lineage, is not the first new variant of the pandemic virus to emerge, but is said to be up to 70% more transmissible than the previously dominant strain in the UK. .

Are the concerns justified?

Most scientists say yes. The new variant has quickly become the dominant strain in COVID-19 cases in parts of southern England and has been linked to an increase in hospitalization rates, especially in London and the adjacent county of Kent.

While it was first seen in Britain in September, in the week of December 9 in London, 62% of COVID-19 cases were due to the new variant. That compared to 28% of cases three weeks earlier.

The governments of Australia, Italy and the Netherlands say they detected cases of the new strain. It was identified in the Netherlands in early December.

Iceland and Denmark have also reported some cases of COVID-19 with the new variant to the ECDC, the European disease monitoring agency. Media reports in Belgium say cases have also been detected there.

“It’s okay to take it seriously,” said Peter Openshaw, professor of experimental medicine at Imperial College London.

Shaun Fitzgerald, a visiting professor at the University of Cambridge, said the situation was “extremely worrying.”

Why?

The main concern is that the variant is significantly more transmissible than the original strain. It has 23 mutations in its genetic code, a relatively high number of changes, and some of them are affecting its ability to spread.

Scientists say it is between 40% and 70% more transmissible. The UK government said on Saturday that it could increase the reproduction rate “R” by 0.4.

This means that it is spreading faster in Britain, making the pandemic even more difficult to control and increasing the risk that it will spread rapidly in other countries as well.

“The new B.1.1.7 … still appears to have all the human lethality that the original had, but with a higher transmission capacity,” said Martin Hibberd, professor of emerging infectious diseases at the School of Hygiene and Tropical Medicine. London.

Will covid-19 vaccines protect against this variant?

The scientists say there is no evidence that the vaccines currently being rolled out in the UK, made by Pfizer and BioNtech, or other COVID-19 injections in development, do not protect against this variant. ” , effect on the efficacy of the vaccine, “said Adam Finn, a vaccine specialist and professor of pediatrics at the University of Bristol.

Britain’s chief scientific adviser, Patrick Vallance, also said that COVID-19 vaccines appeared to be suitable for generating an immune response to the variant of the coronavirus.

“We are not seeing … any serious spike protein changes that reduce the effectiveness of the vaccine so far,” said Julian Tang, professor and clinical virologist at the University of Leicester.

Does the new variant affect testing?

Up to a point, yes.

One of the mutations in the new variant affects one of the three genomic targets used by some PCR tests. This means that in those tests, that target area or “channel” would be negative. “This has affected the ability of some tests to detect the virus,” said Robert Shorten, a microbiology expert at the Association for Clinical Biochemistry. & Laboratory medicine.

However, since PCR tests generally detect more than one target gene, a mutation in the spike protein only partially affects the test, reducing the risk of false negative results.

Are there other important variants of SARS-CoV-2?

Yes. In recent months, strains of the virus that cause COVID-19 have emerged in South Africa, Spain, Denmark and other countries that have also raised concern.

However, so far, none have been found to contain mutations that make them more deadly, or more likely to evade vaccines or treatments.

Did this new variant originate in Great Britain?

Vallance said on Saturday that he thought the new variant could have started in the UK. Some scientists in Europe have credited British expertise in genomic surveillance to identify the mutation.

“The UK has one of the most comprehensive genetic surveillance programs in the world: 5-10% of all virus samples are genetically tested. Few countries are doing better, ”Steven Van Gucht, director of viral diseases at the Belgian Institute of Health, told a news conference on Monday.