LONDON – All week, a fleet of courier ferries has been refrigerating the waste from half a million Covid 19 tests to a genome sequencing facility in Cambridgeshire, eastern England.
The day-to-day work is part of the Covid 19 surveillance system that has made the UK the world’s leading sequencer of the coronavirus genome and led to the discovery of a more infectious and potentially deadly variant of the virus that would have long gone undetected in most countries.
Sequencing the virus – creating a kind of bar code for it – has become crucial in recent months in the global hunt for versions of the pathogen that are better suited to infect people, escape vaccines and ultimately kill them. The virus variants first identified in the UK, South Africa and Brazil have raised concerns among experts.
The sequencer variant found in the UK, which is now the dominant variant in the country, has a mutation that appears to bind better to human cells. Studies show that this variant is 50% more transmissible than the previously common variant, while other studies suggest that it could be at least 30% more deadly.
New viral variants are more likely in the UK than elsewhere. From 29. By January, the UK had archived 44%, or about 190,000, of the genomes in the world library managed by the nonprofit organization Global Initiative for Sharing All Influenza Data, or Gisaid. This represents about 5.1% of the nearly four million cases in the UK.
The United States is rapidly expanding its sequencing capacity, but few other countries have contributed more than 1% of the library, meaning that scientists understand where and how the virus mutates and that it is inconsistent.
This is a weakness in the global response to the pandemic: Early detection of new variants allows governments to impose restrictions and limit travel from countries where new problematic variants occur. It can also help vaccine developers update vaccines.
The UK says it intends to address this weakness by exporting its expertise to countries with limited capacity to work coherently.
Half of the UK genome sequences were generated at the Wellcome Sanger Institute in Cambridgeshire, where samples and genome sequences from Covid-19 positive test by-products from five major UK laboratories are stored, sorted and selected.
Frozen Covid-19 test samples awaiting gene sequencing at the Wellcome Sanger Institute in Hinxton, England.
Dan Ross/Agence France-Presse/Getty Images
Since December, the United States has increased its contribution to the global coronavirus genome database and has now added 20% of the total. She estimated that the incidence of Covid 19 in America is about 0.3%.
The chief medical officer for the Covida 19 pandemic told CBS Sunday that U.S. authorities should expand genomic surveillance to identify variants of the virus.
Britain’s capabilities are partly based on history. British scientists discovered the double helix of DNA and were part of an international team that sequenced the human genome for the first time.
The UK was one of the first countries in the world to recognise the need for a viral genome sequencing infrastructure and we supported it with a huge investment long before Covid arrived, the health minister said.
said in his speech on Tuesday.
The country’s National Health Service, which has a wealth of data, is also closely linked to an extensive network of researchers in universities and the pharmaceutical industry.
Nevertheless, large-scale sequencing of coronaviruses has hardly begun in the UK.
British Health Minister Matt Hancock spoke about the coronavirus last week.
John Sibley/Zuma Press
On the fourth. March, when four cases of Covid-19 were reported in the UK, microbiologist.
contacted by phone a group of other scientists who agreed with her that sequencing the genome of the virus to monitor mutations would be critical to tracking the spread of the virus across the country and determining the source of outbreaks.
They met the opposition. Some scientists thought that large-scale sequencing of the genome of a virus that mutates more slowly than some others, such as influenza, would not make sense.
At the time, some people said there weren’t enough mutations to make it worthwhile, says Dr. Peacock, who is now director of Covid-19 Genomics, a British network that tracks the lineage of coronaviruses.
The eleventh. In March, on the same day that the World Health Organization announced a global pandemic, Dr. Peacock met in London at the Wellcome Trust with 19 others, including clinical virologists, technologists, human genome sequencing experts, and vaccine specialists, to develop a plan for large-scale sequencing of the coronavirus.
It was no ordinary scientific meeting, it was a big debate about how we could do it, Dr. Peacock recalls. By the end of the day, they had the drawing, and on the 18th. In March they presented it to the Chief Scientist of England. It was accepted and adopted at 1. In April, £20 million, equivalent to $27 million, was allocated to the creation of COG-UK.
I am pleased that our consortium of over 600 people can contribute to our understanding of the disease, she added.
However, the country’s success in opening options seems to have more to do with intuition than strategy.
The UK Genome Sequence Inference Scale, which assessed up to 10% of all positive coronavirus tests in the UK at specific times during the pandemic, was developed to identify superproliferation events where identical sequences closely related to their progenitors occur simultaneously.
When an RNA virus like the one that causes Covid-19 multiplies in a new host, errors in the genetic code can occur. Most are not applicable, some are corrected and straightened out, and sometimes there are no errors at all. But some of the bugs, or mutations, in large numbers or of importance in modifying the virus to affect its biology, in rare cases, give it an advantage over its predecessors.
For example, coronaviruses mutate more slowly than some other viruses. B. influenza, so scientists initially did not think there would be enough mutations to make large-scale genome sequencing worthwhile.
But because the virus has infected so many people – more than 100 million worldwide – it has had ample opportunity to mutate. Some changes, including the British variant, which has now been spotted in at least 64 countries, offer evolutionary advantages over their predecessors, making this version of the virus more transmissible.
The new variant came to the attention of experts in November, when a variant with bigger changes than its predecessor began to cluster in a corner of southeast England, resulting in a series of identical genomes that lit up red on genomologists’ screens.
this month in London, where a new variant of the virus emerged in September.
Initially, sequencers did not know whether this variant gained popularity due to widespread disregard for coronavirus restrictions or whether it led to an increase in new cases,
director of the Covid-19 genomics initiative at the Wellcome Sanger Institute, said so during a webinar this month.
By the last week of November, it was clear that a cluster of mutated genomes was occurring at the same site, with Covid-19 cases increasing in the community despite the application of the national blockade.
By examining genomic databases, the sequencers found the first occurrence of the highly mutated variant at age 20. September in Kent, in the south-east of England, and another one a day later in London. The geographical overlap of the genome cases allowed the virus detectives to say with a high degree of certainty that it was not a coincidence, and to label the virus as one of the problem cases.
Email Joanna Sugden at [email protected]
Copyright ©2020 Dow Jones & Company, Inc. All rights reserved. 87990cbe856818d5eddac44c7b1cdeb8