Lessons from the UK on a more contagious Covid-19 variant

“Increasingly, since this version of the virus was discovered, we’ve actually been running two separate pandemics,” said Jason Leitch, Scotland’s national clinical director. “This is a warning to other countries.”

British scientists detected the new variant in November and, in early December, located its first appearance in the United Kingdom as far as Kent County, in southern England, in September. The country was closed in November to suppress a deadly wave of infection that had been building since the fall. British public health officials were baffled by the continued spread of the virus in the south of England despite these restrictions.

When scientists examined the genome of the variant, they found an unusually large number of mutations, some of which pointed to the possibility that the new variant could spread faster than pre-existing versions. Additional sequencing — and a peculiarity of evidence that served as a reliable proxy for the presence of the variant — revealed how quickly the variant reached the domain.

When the blockade was lifted in early December, the new variant was national. The overall rate of cases per 100,000 people multiplied by five in London and the new variant was soon detected in almost every corner of the UK Another stricter national closure was imposed on 4 January to stop its spread . Since then, charges have receded and the government has released plans for a gradual reopening in the coming months.

Public health officials began investigating the contact patterns of people known to be infected with the new variant, now known as B.1.1.7. They found evidence that people infected with the variant infected more people than those infected with the previously dominant strain. This finding reinforced genetic analysis that pointed to a more transmissible version of the pathogen.

“We haven’t seen anything like the UK variant in terms of its growth rate, in terms of its transmissibility,” said Nick Loman, a professor of microbial genomics and bioinformatics at the University of Birmingham.

Even more worryingly, when officials and public health teams from UK universities began examining clinical data on those known to have been infected with B.1.1.7, they detected signs that the variant could be associated with a increased risk of death.

A preliminary analysis, from Scotland, suggested that infection with the variant could be 65% more likely to cause hospitalization and 37% more likely to end in death than contracting the previous version of the virus. Scientists say these findings are not definitive and some studies suggested that the link to higher mortality was weak or that the variant could even be associated with a lower risk of dying.

However, the evidence was enough for a group of scientists to advise the UK government to say this month that B.1.1.7 is likely to carry a higher risk of hospitalization and death than established versions.

Patient surveys conducted by the UK Office for National Statistics between November and January made another finding: B.1.1.7 infection can cause slightly different symptoms, which may help doctors spot possible cases.

The classic symptoms of Covid-19 (fever, cough, and shortness of breath) were slightly more common among those with the new variant than the old one. Patients who reported a loss of taste or smell were less common. And gastrointestinal complaints were more frequent in the case of the new variant.

A cold comfort for the UK, according to public health officials, is that the new variant is now so dominant and so transmissible that other variants of concern to epidemiologists, such as those identified in South Africa and Brazil, have not gained too much. traction. Another reason for optimism is that laboratory tests and some clinical studies, as well as actual vaccination in the UK, suggest that the variant may be neutralized with the current range of vaccines.

Dr. Philip Dormitzer, Pfizer Inc

the scientific head of viral vaccines told British lawmakers on Wednesday that the company saw protection against the British variant in real-world data from Israel and the UK “equivalent to the protection we saw in controlled trials before this variant circulated “.

However, the rapid advancement of the variant and the unusual features make it a concern, disease experts say, especially if vaccine implants do not keep pace.

“It’s a new beast,” said Eric Topol, a professor of molecular medicine at Scripps Research in California. He said he did not believe it was widely appreciated that the new variant could create a new pandemic, “driven by a more difficult virus to fight.”

—Jason French, Andrew Levinson, Max Rust, Josh Ulick, Dov Friedman and Randy Yeip contributed to this article.

Write to Jason Douglas to [email protected] and Joanna Sugden to [email protected]