Study Confirms UK COVID-19 Variant Is More Transmissible, Could Cause Resurgences

A variant of SARS-CoV-2 that was first identified in southeast England in November 2020 has been confirmed to be more transmissible than other variants, according to a press release.

Notably, the study authors said their analyses suggest that the variant could lead to large resurgences of COVID-19 cases. In a press release, they advised continued control measures to avoid further breakouts.

“Without stringent control measures, including limited closure of educational institutions and a greatly accelerated vaccine roll-out, COVID-19 hospitalizations and deaths across England in 2021 will exceed those in 2020,” the authors wrote.

Evidence began to emerge in December that the variant was quickly outcompeting preexisting variants in England. As of February 15, 2021, it comprised approximately 95% of new SARS-CoV-2 infections in the country and was identified in at least 82 countries. Continued research around its growth rate, disease severity, and impact are essential to implement effective policy responses, according to the study.

After analyzing 150,000 sequenced SARS-CoV-2 samples from across the United Kingdom, the team found that the relative population growth rate of the variant in the first 31 days following its initial observation was higher than that of all 307 other virus variant lineages. To understand the potential biological mechanisms for this, the investigators used an age- and regionally-structured mathematical model of transmission to test several assumptions, including that the variant has a higher viral load or longer shedding period.

Based on their analysis, the researchers identified increased transmissibility as the model best explaining the variant’s rapid spread. They estimate that the novel variant has a 43% to 90% higher reproduction number than preexisting SARS-CoV-2 variants in England.

The investigators also used modeling to further analyze how interventions could reduce the potential burden of the variant in the United Kingdom. From the scenarios they assessed, the researchers concluded that a substantially increased vaccine roll-out and school closures throughout 2021 may be necessary to prevent more COVID-19 deaths and hospitalizations.

The investigators did acknowledge some limitations to their analysis, including having only considered a small number of interventions and vaccination scenarios. Despite these limitations, however, they concluded that their projections point to “an urgent need to consider what new approaches may be required to sufficiently reduce the ongoing transmission of SARS-CoV-2.”

REFERENCE
SARS-CoV-2 variant that emerged in UK more transmissible; could spark resurgences [news release]. EurekAlert; March 3, 2021. https://www.eurekalert.org/pub_releases/2021-03/aaft-svt030321.php. Accessed March 4, 2021.