Increased risk of mortality in patients infected with SARS-CoV-2 variant of concern 202012/1

blogs.bmj.com March 19, 2021

We started estimating the SARS-CoV-2 reproduction number in the UK using Public Health England data in March 2020, contributing to the Scientific Pandemic Influenza Modelling subgroup (SPI-M) weekly consensus estimates.

In December 2020, after B.1.1.7 was identified as a variant of concern, data were shared with the SPI-M research groups which allowed us to identify these infections.

These were used by the London School of Hygiene and Tropical Medicine (LSHTM) team to develop estimates of increased transmissibility of B.1.1.7.

We started investigating epidemiological signatures associated with B.1.1.7, including the reproduction number, presentation, and outcome by S-gene status. On 13 January 2021, the LSHTM team presented an analysis to SPI-M which showed a concerning rise in mortality associated with B.1.1.7.

However, given the mounting pressure on intensive care units, the risk of confounding resulting from unavoidable compromises in patient care meant SPI-M could not reach consensus that the new variant was more deadly, based on their work alone.