How British scientists discovered the new Covid-19

On December 8, the group, known as the Covid-19 Genomics UK Consortium, found a new variant of the virus, with 23 mutations, in a sample taken from a patient in Kent, near the center of the outbreak in late September. They found the same variant in someone tested in London a day later.

Some of the new mutations have had the potential to increase the transmissibility of the virus.

“Gathering genome data and details from a Kent outbreak led to the key connection,” said Sharon Peacock, a Cambridge University microbiologist who leads the genomics team. She said in an email that it was the “light bulb moment” of scientists.

New information continued to flow, and the British government first expressed concerns about the variant on December 14, when Health Secretary Matt Hancock told British lawmakers he was responsible for 1,000 cases in London and the south. -Eastern England and spreads.

“The initial analysis suggests that this variant is growing faster than the existing ones,” Mr Hancock said.

Meanwhile, scientists have delved deeper into the nature of the mutations of the new variants.

Viruses move all the time – although coronaviruses are slower than other common viruses, such as the flu. What was noticed in the new variant was that a larger than usual number of mutations affected the code for the amino acids that produce the proteins that produce the virus.

A mutation alters the virus’s spike protein in a known way to make it easier for the virus to stick to cell walls and enter the body. Along with two other mutations, the change has the potential to give the variant a possible advantage over previous versions in infecting humans.

It was a variant that had not been seen before – and the number and nature of its mutations were, scientists say, unprecedented.

“It’s kind of on a branch, it’s really pretty striking that it’s so different from everything else around the UK,” Dr Peacock said.

At the time of the discovery of the new variant, it accounted for 62% of all cases registered in London. And the infections continued to grow rapidly.

The latest data show that the seven-day average of cases from week to Wednesday in the UK has risen by 61% over the previous week, even though the number of cases is declining in most of the rest of Europe. Hospitalizations and deaths – delayed indicators of the spread of the virus – increased by 16% and 20%, respectively.

The “underlying mechanism” that spreads the rapid spread “is not entirely clear – it could be that the virus reproduces faster, which means you get higher viral loads, which means you are more infectious.” Peter Horby, chairman of the New Emerging Respiratory Virus Threats Advisory Group advising the British government, told lawmakers on Wednesday.

Another hypothesis is that it may take less time between being exposed and being infectious, which would lead to faster transmission. Or it could mean that the duration of the infection is longer, said Dr. Horby.

Researchers are now working to answer two key questions: Will the new variant cause more serious diseases and be able to evade vaccines?

British scientists say they do not have enough evidence at this time to answer definitively, but they are working hard to find out.

On the vaccine, they test blood samples from people who have had the vaccine against the new variant to see if it has a different response compared to the previous version.

Widespread opinion among scientists and Pfizer developers Inc.

– The BioNTech SE vaccine is that the vaccine produces antibodies that attack several different sites of the virus, so changes in a small area are unlikely to neutralize the potency of the vaccine.

As for the severity of the disease caused by the new variant, they are waiting for the data on hospitalization and death, which are the cases of delay, to say more.

As they delved deeper into the new variant, British researchers spent the last few weeks quietly searching for the zero patient. They investigated the contacts of the two people who were first identified with the variant, neither of them was ill and others who were infected early.

One hypothesis is that the variant appeared in a person with a compromised immune system. People with deficient immune systems are often the host when viruses undergo a large number of mutations because the virus is able to survive in their system for so long.

“Ideally, you would know who the index case was,” said Dr. Peacock. “We don’t know at all if this happened to a patient in the UK or if he was introduced, we can’t say for sure at this time.”

In the week following the publication of the new variant, new data and epidemiological modeling have made British scientists increasingly convinced that the new variant is reproducing faster than its predecessors. Some models have suggested that it is 50% to 70% more transmissible than other versions.

By December 18, as new infections in the region continued to accelerate, a meeting between government officials and scientists alarmed the government, leading to a significant policy change.

The next day, Prime Minister Boris Johnson announced new blockades for regions where the virus was spreading rapidly and reduced a planned five-day Christmas relaxation to just one day in the rest of the country.

Write to Joanna Sugden at [email protected] and Stephen Fidler at [email protected]