UK variant B.1.1.7 linked to higher risk of death and hospitalisation from COVID-19
Simon Collins, HIV i-Base
On 11 February 2021, the UK government scientific advisory group (SAGE) released a report that convincingly linked the B.1.1.7 variant to higher risks of mortality compared to previous UK strains. Previously, the variant has only been linked with a higher risk of transmission, often stressing a lack of concern for worse clinical outcomes.
The new report includes results from nine different research groups. While noting the importance of additional research that will be compiled over the next few weeks, the largest databases all reported an independent increased risk of mortality from variant B.1.1.7.
- The London School of Hygiene and Tropical Medicine (LSHTM) reported 71% increased risk of death (relative hazard 1.71: 95% CI: 1.48 to 1.97).
- University College London (UCL) reported 36% increased risk of death using case fatality ratio (CFR 1.36: 95%CI 1.18 to 1.56).
- Exeter University: 71% increased risk of death (CFR 1.7: 95% CI 1.3 to 2.2).
- Public Health England (PHE) reported 65% increased risk of death (death risk ratio 1.65: 95%CI: 1.21 to 2.25).
Although these research groups used different methods and smaller studies didn’t always find the same research, there is sufficient evidence to recognise the likelihood that B.1.1.7 has significantly worse outcomes.
The 12-page report includes more details on all studies, including the different mythologies. It concludes that based on these analyses “it is likely that infection with B.1.1.7 is associated with an increased risk of hospitalisation and death compared to infection with [non-variant] viruses.
These results are also plausible. A virus that is easier to transmit (approximately 30% higher) could easily lead to higher levels of virus that in turn could increase severity of symptoms.
SAGE. NERVTAG: Update note on B.1.1.7 severity. (12 February 2021)
This report was first published on 13 February 2021.