Acute COVID-19 mortality in England in the omicron era: a national-level matched cohort study

Journal article

Fluctuations in disease severity occurred throughout the COVID-19 pandemic in England due to emerging variants and changing population immunity. Deaths caused by COVID-19 reduced from 2022; however, a smaller reduction was observed in deaths following a COVID-19 test. This study examines whether mortality risk within 28 days of a positive SARS-CoV-2 test remained elevated during a period of reduced disease severity. National-level routinely collected health data containing SARS-CoV-2 test results, vaccination, hospital, and death records were linked to create a population-level cohort. Individuals testing positive and negative were matched on demographic and disease characteristics. Mortality risk was compared using univariable and multivariable conditional logistic regression models for the overall time-period (March 2020–April 2022) and the focus time-period (January–April 2022). Individuals testing positive in the overall time-period had a 228% increased risk of death than those testing negative. In the focused time-period, test positive individuals had 63% higher odds of death, accounting for vaccination and previous hospitalisation. The increased risk of death associated with testing positive was greater among unvaccinated individuals (238%) than vaccinated individuals (155%). Mortality risk following COVID-19 remained elevated at the end of the pandemic, especially among unvaccinated individuals, supporting continued COVID-19 booster vaccination campaigns.

Authors: Hassell, K; Andrews, N; Dabrera, G; Kall, M; Allen, H

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Cambridge University Press
• Journal: Epidemiology & Infection
• Volume: 154
• Article number: e70
• Publication date: 2026-05-05
• Acceptance date: 2026-04-01
• DOI: 10.1017/s0950268826101472
• EISSN: 1469-4409
• ISSN: 0950-2688
• Language: English
• Keywords: vaccination; COVID-19; data linkage; mortality; SARS-CoV-2