The B.1.1.7 variant of the coronavirus first identified in the U.K. last year does not cause more severe disease among hospitalized patients despite being able to spread more easily according to a new study which comes just a week after the CDC announced that the fast-spreading has now become the dominant strain in the U.S.

Key Facts

The study published in The Lancet medical journal on Monday looked at hospitalization data from last fall in two U.K. hospitals and found that patients infected with the B.1.1.7 variant were not at increased risk of severe illness or death.

The study also found that patients infected with the B.1.1.7 strain had higher viral loads or more quantity of the virus in their bodies.

One of the study’s lead authors Dan Frampton told NBC News the higher viral loads in patients infected with the U.K. variant may be the reason why the virus is more transmissible.

The study observed that patients infected with the B.1.1.7 strain were more likely to be given supplemental oxygen however it noted that this may not correlate with disease severity as several unrelated factors may lead to its administering.

The study, however, did not cover the two other fast-spreading strains first discovered in South Africa and Brazil, both of which have been shown to blunt the effectiveness of Covid-19 vaccines.


Despite the latest findings, there is no clear consensus yet on B.1.1.7 variant’s virulence. A study published in the journal Nature last month found that the variant may be associated with a 61% higher risk of death compared to previous variants. Another study published in the British Medical Journal last month found that people over 30 had a 64% higher risk of death from the U.K. variant compared to other strains.

Key Background

Last week, Rochelle Walensky, the director of the Centers for Disease Control and Prevention (CDC) announced the B.1.1.7 variant had now become the dominant strain of the virus circulating in the U.S. The B.1.1.7 variant was first detected in England late last year and was believed to be behind the surge in cases in the U.K. in January which prompted another lockdown. Since then B.1.1.7 has also become the dominant variant spreading in Europe and is believed to be the cause of the latest surge in cases in the continent.

Big Number

20915. That’s the total number of B.1.1.7 Covid-19 cases that have so far been detected in the U.S. according to CDC’s tracker. The actual number of people infected with the B.1.1.7 variant is likely to be many folds higher as all cases are not genomically sequenced.

Further Reading

U.K. variant isn’t linked to more severe disease or death, study finds (NBC News)

U.K. Strain Doesn’t Result in More Severe Covid-19 Among Hospitalized Patients, Study Finds (Wall Street Journal)