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Project #80:
Analysis of the relative severity of the SARS-CoV-2 Alpha variant compared to wild type virus

The SARS-CoV-2 Alpha variant was first identified in Kent, UK in autumn 2020. The variant was more transmissible than the prevalent wild type virus and quickly became the dominant circulating form of the virus.

This study aimed to estimate the relative severity of the SARS-CoV-2 Alpha variant compared to the previously circulating wild type virus.

The study population was defined by all people testing positive for SARS-CoV-2 in the window 16th November 2020 to 11th January 2021, with data available on the gene marker that can differentiate between the two virus types (SGTF).

The exposure of interest was infection with the Alpha variant. The outcomes of interest were hospital admission, admission to the intensive care unit (ICU), and all-cause mortality.

The key finding of this research is that infection with the Alpha variant is associated with a 70% increased risk of all-cause death compared to wild type virus.


  • Study leads: daniel.grintroz.eggo
  • Organisation: University of Oxford and London School of Hygiene and Tropical Medicine
  • Project type: Research
  • Topic area: Risk from COVID (short term) [e.g. hospitalisation/death]
  • Code on GitHub: opensafely/SGTF-CFR-research