UK lessons on a more contagious Covid-19 variant

“Increasingly, since this version of the virus was discovered, we really have 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, tracked its first appearance in the United Kingdom in Kent County in southern England in September. The country was closed in November to suppress a deadly wave of infection that had been growing since the fall. British public health officials were puzzled by the continued spread of the virus in southern England, despite these restrictions.

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

When the blockade was lifted in early December, the new variant became national. The overall case rate per 100,000 people increased five times in London, and the new variant was soon detected in almost every corner of the UK. Another stricter national blockade was imposed on January 4 to contain its spread. Since then, the number of cases has declined and the government has published plans for a scheduled reopening in the coming months.

Public health officials began investigating 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 started to infect more people than those infected with the previously dominant strain. This finding reinforced the genetic analysis that pointed to a more transmissible version of the pathogen.

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

More worryingly, when public health officials and staff at UK universities began to examine clinical data on those known to be infected with B.1.1.7, they detected signs that the variant may be associated with an increased risk of death .

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

Still, the evidence was sufficient for a panel of scientists advising the UK government to say this month that B.1.1.7 is likely to carry a greater risk of hospitalization and death than established versions.

Patient surveys conducted by the UK’s Office of National Statistics between November and January revealed another finding: infection with B.1.1.7 can result in slightly different symptoms, which can help doctors detect 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 with the old. Patients who reported loss of taste or smell were less common. Gastrointestinal complaints were more frequent in the case of the new variant.

A cold consolation for the United Kingdom, according to public health officials, is that the new variant is now so dominant and transmissible that other variants of concern to epidemiologists, such as those identified in South Africa and Brazil, have not gained much momentum. . Another reason for optimism is that laboratory tests and some clinical studies – as well as vaccination in the real world in the UK – suggest that the variant may be neutralized by the current variety of vaccines.

Dr. Philip Dormitzer, Pfizer Inc.’s

scientific director of viral vaccines, told UK lawmakers on Wednesday that the company was seeing protection against the UK variant in real-world data from Israel and the UK “equivalent to the protection we saw in controlled tests before this circular variant “.

Still, the variant’s rapid advance and unusual characteristics mean that it remains a concern, say disease experts, especially if vaccine launches don’t 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 think it was widely appreciated that the new variant could create a new pandemic, “driven by a more resistant virus 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]