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Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) alpha variant (B.1.1.7) is associated with higher transmissibility than wild-Type virus, becoming the dominant variant in England by January 2021. We aimed to describe the severity of the alpha variant in terms of the pathway of disease from testing positive to hospital admission and death. Methods: With the approval of NHS England, we linked individual-level data from primary care with SARS-CoV-2 community testing, hospital admission, and Office for National Statistics all-cause death data. We used testing data with S-gene target failure as a proxy for distinguishing alpha and wild-Type cases, and stratified Cox proportional hazards regression to compare the relative severity of alpha cases with wild-Type diagnosed from 16 November 2020 to 11 January 2021. Results: Using data from 185 234 people who tested positive for SARS-CoV-2 in the community (alpha=93 153; wild-Type=92 081), in fully adjusted analysis accounting for individual-level demographics and comorbidities as well as regional variation in infection incidence, we found alpha associated with 73% higher hazards of all-cause death (adjusted hazard ratio [aHR]: 1.73; 95% confidence interval [CI]: 1.41-2.13; P

Original publication




Journal article


Clinical Infectious Diseases

Publication Date





E1120 - E1127