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

“Increasingly, since this version of the virus was discovered, we’ve really had two separate pandemics,” said Jason Leitch, National Clinical Director for Scotland. “It’s a warning to other countries.”

British scientists detected the new variant in November and in early December traced its first appearance in the UK in Kent County, southern England, in September. The country was on lockdown in November to quell a wave of deadly infection that had built up since the fall. British public health officials have been mystified by the continued spread of the virus in southern England despite these restrictions.

When scientists examined the variant’s genome, they found an unusually high number of mutations, some of which pointed to the possibility that the new variant could spread faster than the pre-existing versions. Further sequencing – and a testing quirk that served as a reliable proxy for the presence of the variant – revealed how quickly the variant became dominant.

When the lockdown was lifted in early December, the new variant went national. The overall rate of cases per 100,000 population has increased fivefold in London, and the new variant was quickly detected in almost every corner of the UK. Another, stricter national lockdown was imposed on January 4 to stop its spread. The number of cases has since declined and the government has released plans to reopen in stages in the coming months.

Public health officials have started probing the contact patterns of people known to be infected with the new variant, now widely 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 discovery reinforced the genetic analysis indicating a more transmissible version of the pathogen.

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

Even more worrying, when public health officials and teams at UK universities began looking at clinical data on people known to have been infected with B.1.1.7, they detected signs that the variant could be associated at a higher risk of death.

A preliminary analysis, carried out in Scotland, suggested that infection with the variant could be 65% more likely to result in hospitalization and 37% more likely to end in death than to contract the older version of the virus. Scientists say these results are not definitive, and some studies have suggested that the link to higher mortality is weak, or that the variant may even be associated with a lower risk of dying.

Still, there was enough evidence for a panel of scientists advising 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 came to another conclusion: an infection with B.1.1.7 can cause slightly different symptoms, which can help doctors spot cases. possible.

Classic symptoms of Covid-19 – fever, cough, and shortness of breath – were slightly more common in people with the new variant than in the old one. Patients reporting loss of taste or odor 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 much ground. . Another reason for optimism is that laboratory tests and some clinical studies – as well as real-world vaccination in the UK – suggest that the variant can be neutralized by the current range of vaccines.

Dr Philip Dormitzer, Pfizer Inc. of

The chief scientist for viral vaccines told UK lawmakers on Wednesday the company sees protection against the UK variant in real-world data from Israel and the UK “equivalent to the protection we’ve seen in controlled trials before this variant circulates ”.

Still, the variant’s rapid advance and its unusual characteristics mean it remains a concern, disease experts say, especially if vaccine deployments don’t keep pace.

“It’s a new beast,” said Eric Topol, professor of molecular medicine at Scripps Research in California. He said he didn’t think it was widely appreciated that the new variant could create a new pandemic, a “push by a virus that is harder to fight.”

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

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