UK COVID-19 variant not associated with higher disease severity, mortality among hospitalized patients, study finds

New study data suggest that the variant of COVID-19 originating in the United Kingdom does not cause more severe illness among hospitalized patients.

Formally known as B.1.1.7, the variant is known to be more transmissible than prior strains, and last week was declared by the CDC to be the most common strain of coronavirus currently circulating in the United States.

“Our data, within the context and limitations of a real-world study, provide initial reassurance that severity in hospitalized patients with B.1.1.7 is not markedly different from severity in those without, and this study provides a model to answer the same question again as we move into an era of emerging variants,” the researchers wrote in the study.

Led by University College London researchers and published yesterday in The Lancet Infectious Diseases, the investigation monitored 496 patients admitted to two London hospitals between November 9, 2020 and December 20, 2020. Of the 341 of these patients for whom sequencing data were available, 58% had B.1.1.7.

Although the researchers found increased viral load among those with the B.1.1.7 variant, they found similar rates of severe disease and mortality in unadjusted analyses, and analyses adjusted for age, sex, comorbidities, ethnicity and admitted hospital. The researchers did not correct their outcomes comparisons for receipt of treatments.

Patients with the variant strain were more often younger, had fewer comorbidities and more often were an ethnic minority. The only significant difference in treatment between the two groups was more frequent receipt of oxygen among those with B.1.1.7.

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The researchers noted that these findings do not speak to whether infection with B.1.1.7 over another strain increases the risk of hospitalization. It’s possible that increased transmissibility alone could be responsible for the uptick in hospitalization volume tied to the variant, they wrote.

The good news on COVID-19 variants from the U.K. study came around the same time early data from an Israeli investigation suggests that Pfizer’s COVID-19 vaccine protects against the B.1.351 variant first identified in South Africa — but not quite to the extent that it does against B.1.17 or other strains.

These findings, which have yet to be peer-reviewed and should not be used to inform clinical practice, were generated among members of Clalit Health Services, Israel’s largest healthcare organization, with documented COVID-19 infection.

Meanwhile, the CDC came out with its own study this week highlighting higher rates of COVID-19 hospitalizations among racial and ethnic minority groups, particularly Latinos and Hispanics, compared to white patients in the U.S. This analysis reviewed administrative discharge data from roughly 300,000 hospitalized patients collected between March 2020 to December 2020.