Lessons From the U.K. About a More-Contagious Covid-19 Variant
LONDON—The U.K. has become a testing ground for how a more-contagious and possibly deadlier coronavirus variant spreads through communities, displacing its less-transmissible ancestors and complicating vaccine rollouts and the lifting of lockdowns. The variant has now been identified in more than 70 countries and 40 U.S. states, and its advance in Britain could help scientists understand its likely trajectory in the U.S. These charts show the spread of the variant around the U.K. and what British scientists are learning about it—including its higher transmissibility and lethality.
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When scientists examined the variant’s genome, they found an unusually large number of mutations, some of which pointed to the possibility the new variant could spread more rapidly than pre-existing versions. Further sequencing—and a testing quirk that served as a reliable proxy for the variant’s presence—revealed how quickly the variant rose to dominance. When lockdown lifted in early December, the new variant went national. The overall case rate per 100,000 people increased fivefold in London, and the new variant was soon detected in almost every corner of the U.K. Another, stricter nationwide lockdown was imposed Jan. 4 to arrest its spread. Caseloads have since fallen back and the government has published plans for a staged reopening in the coming months.
Public-health officials began 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 went on to infect more people than those infected with the previously dominant strain. That finding reinforced the genetic analysis pointing to a more transmissible version of the pathogen... More worrying still, when public-health officials and teams at U.K. universities began examining clinical data on those known to have been infected with B.1.1.7, they detected signs the variant might be associated with a higher risk of death.
One preliminary analysis, from Scotland, suggested infection with the variant could 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 aren’t definitive, and some studies suggested the link with higher mortality was weak or the variant may even be associated with a lower risk of dying. Still, the evidence was sufficient for a panel of scientists advising the U.K. government to say this month that it is likely B.1.1.7 carries a greater risk both of hospitalization and death than established versions.
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One cold comfort for the U.K., 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, haven’t gained much traction. Another reason for optimism is that lab tests and some clinical studies—as well as real-world vaccination in the U.K.—suggest the variant can be neutralized by the current range of vaccines.
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https://www.wsj.com/articles/lessons-from-the-u-k-about-a-more-contagious-covid-19-variant-11614253429 (subscription)