U.K. COVID-19 Variant More Deadly Than Other Strains, Researchers Say

COVID-19 variant illustration.

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Key Takeaways

  • The U.K. strain of SARS-CoV-2 appears to be much more lethal as well as more transmissible than other strains of the virus. 
  • Researchers in England have found that infection with B.1.1.7 is between 32% and 104% more likely to cause death than infection with other strains. 
  • These results demonstrate the ongoing importance of masking, social distancing, and taking other basic public health safety precautions. 

Recently, researchers at the University of Bristol and the University of Exeter found that infection with B.1.1.7, a strain of SARS-CoV-2 that first surfaced in the U.K. in October, is associated with a higher risk of death than infection with other previously known strains of the virus.

Designated a “variant of concern” by Public Health England in December, B.1.1.7 has already spread to more than 50 countries around the world, including the United States and Canada, and has even emerged as the dominant strain of the novel coronavirus in some regions.

In the U.K., it now accounts for three-quarters of all infections; in Florida, more than half, according to Robert Challen, PhD, a postdoctoral research associate in the department of mathematics at the University of Exeter and a lead author of the study; in Connecticut, more than a quarter. What’s more, it shows no signs of slowing down. 

Thus far, doctors and scientists have tentatively attributed some of B.1.1.7's early success to one or more genetic mutations that enhance the ability of the virus’ spike proteins to bind to host cell receptors. Most likely thanks to these mutations, B.1.1.7 is more easily transmitted than earlier strains.

But Challen’s work suggests it may also be more lethal. The March study was published in The British Medical Journal

“The increase in transmissibility and in severity means more caution is required, and in the face of a wave of new variant infections, public health bodies should be prepared to act quicker to prevent hospitals being overrun,” Challen tells Verywell. 

What This Means For You

Even as COVID-19 vaccination increases, COVID variants are a cause for concern. The U.K. variant in particular can be more easily transmitted and may be deadlier. In order to protect yourself from COVID-19 variants, continue practicing safety precautions like wearing a mask and washing your hands. But consider taking your measures one step further by double-masking or wearing a three-layer face mask.

Just How Much More Dangerous Is the U.K. Strain?

Challen and colleagues analyzed data on COVID-19 cases that occurred in the U.K. between October 2020 and January 2021. They compared death rates between 54,906 people infected with B.1.1.7 and 54,906 similar people infected with other strains of the novel coronavirus.

During the study, 227 of the people infected with B.1.1.7 died and 141 of the people infected with other strains died. B.1.1.7 caused 86 more deaths than its counterparts.

The significant difference in death suggested a significant difference in disease lethality, which the authors determined as “a 32% to 104% increased risk of death, with the most probable hazard ratio estimate of 1.64, or a 64% increased risk of death.”

Put another way, 4.1 out of every 1,000 B.1.1.7 infections are fatal, compared to only 2.5 out of every 1,000 non-B1.1.7-SARS-CoV-2 infections. Going forward, the authors warn, clinicians and public health officials should expect death rates to increase in proportion to B.1.1.7's prevalence.

However, Stanley Perlman, MD, PhD, professor of microbiology and immunology at the University of Iowa’s Carver College of Medicine who was not involved with the study, cautions against jumping to conclusions. While these findings are concerning, after all, they are also brand-new. Additionally, B.1.1.7 has not yet exhibited any vaccine resistance to the currently authorized vaccines.

“B.1.1.7 may be slightly more lethal, but this is preliminary,” Perlman tells Verywell. 

Preliminary or not, Challen advises against taking unnecessary chances with your health. If we loosen COVID-19 safety precautions too soon, variants may cause a resurgence in cases. “The public should take more stringent measures to protect themselves and others around them, according to local public health advice,” Challen says. 

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Challen R, Brooks-Pollock E, Read J M, Dyson L, Tsaneva-Atanasova K, Danon L et al. Risk of mortality in patients infected with SARS-CoV-2 variant of concern 202012/1: matched cohort study. BMJ. 2021;372(579). doi:10.1136/bmj.n579

  2. University of Exeter. Variant B.1.1.7 of COVID-19 associated with a significantly higher mortality rate, research shows. March 10, 2021.

By Caroline Tien
Caroline Tien is a journalist with degrees in English and biology. She has previously written for publications including Insider and Cancer Health.