British public health officials were devastated. Nationwide restrictions reduced the spread of coronavirus across much of the country by the end of November. But in one part of the south-east of England disease was largely prevalent.
Epidemiologists wanted to investigate, initially assuming that there had been an event of some kind or that people were evading social distance rules at work, in illegal house parties, or elsewhere . They found nothing. Stumped, they turned to a team of scientists monitoring mutations in the virus genome.
On 8 December the group, known as the UK Covid-19 Genomics Consortium, discovered a new strain of the virus, with 23 mutations, in a sample taken from a patient in Kent, near the center of the virus. out at the end of September. They found the same difference in someone who was diagnosed in London a day later.
Some of the new mutations had the potential to increase the transmission of the virus.
“Combining the genome data and details of a revolution in Kent became the key link,” said Sharon Peacock, a Cambridge University microbiologist who leads the genomics team. She said in an email that the scientists had “the light bulb moment”.
The UK increased restrictions after announcing a new version of the coronavirus that appears to be more portable.
New information continued to flow and the British government publicly raised its concerns about the opposite on December 14, when health secretary Matt Hancock told British lawyers he was responsible for 1,000 cases in London and beyond. southeast of England and that it was spreading.
“The initial study shows that this variable is growing faster than the current changes,” said Hancock.
At the same time, scientists were digging deeper into the mutated nature of the new variables.
Viruses circulate all the time – although coronaviruses are slower than some other common viruses such as the flu. What stood out in the new variant is that a larger than normal number of mutations affected the code for the amino acids that make up the proteins that make up the virus.
One mutation alters the virus’s spike protein in a way that is known to make it easier for the virus to adhere to cell walls and enter the body. Along with two other modifications, the change has the potential to take advantage of the variance over previous versions in infecting humans.
It was an unprecedented change – and the number and nature of its mutations, scientists say, were unparalleled.
“It’s a bit out of line, it’s really interesting that it’s so different from everything else around it in the UK,” said Dr Peacock.
At the time the new variant was discovered, it made up 62% of all cases recorded in London. And diseases have continued to rise rapidly.
The latest data shows that the UK average of seven days of cases per week to 23 December was up 61% over the previous week, even as case numbers fall in the UK. most of the rest of Europe. Hospitals and deaths – signs of a slow spread of the virus – were up 16% and 20%, respectively.
The “basic tool” that drives a quick spread is not entirely clear – this could be because the virus reproduces faster, which means you get higher viral loads which means you are more infectious, ”said Peter Horby, chairman of the New Respiratory Virus Threats featuring an Advisory Group briefing the British government, telling lawyers on 23 December .
Another possible idea is that it takes a shorter time between being open and being infectious, which would lead to faster spread. “Or it could mean a longer period of infection,” said Dr Horby.
Researchers are now working to answer two important questions: Will the new variant make disease more dangerous and will it be able to avoid vaccines?
British scientists say they do not currently have enough evidence to respond definitively but are working hard to find out.
On the vaccine, they test blood samples from people who have been vaccinated against the new variant to see if they show a different response to the one who received the previous version.
The widespread view among scientists and developers of the Pfizer / BioNTech vaccine is that the vaccine produces antibodies that attack several different sites of the virus and therefore the changes in a small area are unlikely to negate the strength of the vaccine.
On the severity of the disease caused by the new variant, they are waiting for hospital and death data, which counts weak cases, to tell them more.
As they have gotten into the new variant, British researchers have spent a few weeks quietly hunting for zero patients. They have moved through the ties of the two who were first identified with the variant, none of whom were ill, and others who were infected early.
One hypothesis is that the variant arose in a person with an immune system. People with immune systems are often the guest when viruses come through many mutations because the virus is able to live in their system for so long.
“In exceptional circumstances you would know what the index issue is,” said Dr Peacock. “We do not know at all, if this has arisen in patients in the UK or if it has been introduced, we cannot state clearly at this time.”
In the week after the new variant was announced, new data and epidemiological modeling more and more confirmed to British scientists that the new variant was breeding faster than before. Some models suggested that it was 50% to 70% more mobile than other versions.
By December 18, as new diseases in the region accelerated, a meeting between government officials and scientists alarmed the government, prompting a major shift in policy.
The next day, Prime Minister Boris Johnson announced new locks for regions where the virus was spreading rapidly and cut a planned five-day Christmas break of restrictions to just one day in the rest of the week. country.
This article was published by The Wall Street Journal.