Countries reporting B.1.1.7 - Credit CDC
While there are a number of SARS-CoV-2 variants of concern circulating around the world - including P.1 from Brazil and B.1.351 from South Africa - the variant which has spread the farthest, and that we know the most about, is UK B.1.1.7.
Although the alarm was first raised in the UK just 90 days ago, it has now been reported from 94 countries, is the dominant lineage in both the UK and Denmark, and is believed on track to become dominant in the United States sometime in April (see MMWR: Emergence Of SARS-CoV-2 B.1.1.7 Lineage — United States, Dec 29, 2020–Jan 12, 2021).
To make matters worse, not only is B.1.1.7 more transmissible, we've seen mounting evidence that it produces more severe illness - and higher mortality - than the older `wild type' COVID viruses (see Updated NERVTAG Report On Increased Severity With COVID Variant B.1.1.7).
There are admittedly limitations to these studies, and not everyone is on board with these claims of increased mortality (see discussion on Science Media Centre), but we've seen some fairly consistent results coming from independent studies both in the UK and Denmark.
BMJ: Risk of Mortality in Patients Infected with SARS-CoV-2 VOC 202012/1 (B.1.1.7)
SSI: COVID Variant B.1.1.7 Increases Risk of Hospitalization 64%
Today we can add yet another (preprint) study to the list - this time from the London School of Hygiene and Tropical Medicine (LSHTM) - that finds a 55% higher mortality among those infected with this emerging variant.
First some excerpts from the LSHTM news release, followed by a link and the abstract from the preprint.
B.1.1.7 variant linked to 55% higher mortality compared to other strains of SARS-CoV-2
15 March 2021
New variant threatens to cancel out the improvements in COVID-19 treatment
The B.1.1.7 variant is very likely to cause more severe illness than pre-existing SARS-CoV-2 variants, according to new research published in Nature.
The research team at the London School of Hygiene & Tropical Medicine analysed the results of more than two million COVID-19 community tests in England between November 2020 and February 2021.
Linking the test results to a comprehensive database of COVID-19 deaths, they estimated that B.1.1.7 infection was associated with 55% (95% confidence interval 39–72%) higher mortality compared to other strains of SARS-CoV-2 over this time period.
For example, out of 1,000 people in their 60s who test positive for the old variant, six of them might be expected to die from COVID-19 in the four weeks following the test. But this rises to about nine with the B.1.1.7 variant.
The authors concluded that the emergence of new SARS-CoV-2 variants such as B.1.1.7 threatens to cancel out the improvements in COVID-19 treatment that were made over the course of 2020. This work highlights the importance of vaccination programmes to control the spread of the coronavirus.
The findings build on recent research by LSHTM, published in Science, which concluded that this new variant is 43–90% more transmissible than pre-existing variants circulating in England.
Researchers around the world have been working to establish if these variants also cause more severe disease, a threat which this new study aimed to shed more light on.
Dr Nick Davies, lead author from LSHTM’s Centre for the Mathematical Modelling of Infectious Diseases, said:
"England has suffered an enormous toll from B.1.1.7 in the last few months, with 42,000 COVID-19 deaths in January and February 2021 alone. In spite of substantial advances in COVID-19 treatment, we have already seen more deaths in 2021 than we did over the first eight months of the pandemic in 2020. Our work helps to explain why.
The B.1.1.7 variant is more transmissible, and our research provides strong evidence that is also causes more severe illness. This should serve as a warning to other countries that they need to remain vigilant against B.1.1.7, which has already spread to over 90 countries worldwide."
Over the last three months, the world has entered a new phase of the COVID-19 pandemic. While life-saving vaccines against COVID-19 have started to be rolled out in many countries across the globe, SARS-CoV-2, like all viruses, has mutated over time.
Article
Published: 15 March 2021
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Increased mortality in community-tested cases of SARS-CoV-2 lineage B.1.1.7
Nicholas G. Davies, Christopher I. Jarvis, CMMID COVID-19 Working Group, W. John Edmunds,
Nicholas P. Jewell, Karla Diaz-Ordaz & Ruth H. Keogh
Nature (2021) Cite this article
Abstract
SARS-CoV-2 lineage B.1.1.7, a variant first detected in the UK in September 20201, has spread to multiple countries worldwide. Several studies have established that B.1.1.7 is more transmissible than preexisting variants, but have not identified whether it leads to any change in disease severity2.Here we analyse a dataset linking 2,245,263 positive SARS-CoV-2 community tests and 17,452 COVID-19 deaths in England from 1 September 2020 to 14 February 2021. For 1,146,534 (51%) of these tests, the presence or absence of B.1.1.7 can be identified because of mutations in this lineage preventing PCR amplification of the spike gene target (S gene target failure, SGTF1). Based on 4,945 deaths with known SGTF status, we estimate that the hazard of death associated with SGTF is 55% (95% CI 39–72%) higher after adjustment for age, sex, ethnicity, deprivation, care home residence, local authority of residence and test date. This corresponds to the absolute risk of death for a 55–69-year-old male increasing from 0.6% to 0.9% (95% CI 0.8–1.0%) within 28 days after a positive test in the community. Correcting for misclassification of SGTF and missingness in SGTF status, we estimate a 61% (42–82%) higher hazard of death associated with B.1.1.7. Our analysis suggests that B.1.1.7 is not only more transmissible than preexisting SARS-CoV-2 variants, but may also cause more severe illness.
Author information
These authors contributed equally: Karla Diaz-Ordaz & Ruth H. Keogh
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