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Symptom prevalence, duration, and risk of hospital admission in individuals infected with SARS-CoV-2 during periods of omicron and delta variant dominance: a prospective observational study from the ZOE COVID Study

Open access
Menni, Cristina, Valdes, Ana M, Polidori, Lorenzo, Antonelli, Michela, Penamakuri, Satya, Nogal, Ana, Louca, Panayiotis, May, Anna, Figueiredo, Jane C, Hu, Christina, Molteni, Erika, Canas, Liane, Österdahl, Marc F, Modat, Marc, Sudre, Carole H, Fox, Ben, Hammers, Alexander, Wolf, Jonathan, Capdevila, Joan, Chan, Andrew T, David, Sean P, Steves, Claire J, Ourselin, Sebastien, Spector, Tim D·2022·The Lancet

Abstract

BACKGROUND: The SARS-CoV-2 variant of concern, omicron, appears to be less severe than delta. We aim to quantify the differences in symptom prevalence, risk of hospital admission, and symptom duration among the vaccinated population. METHODS: , had received at least two doses of any SARS-CoV-2 vaccine, were symptomatic, and logged a positive symptomatic PCR or lateral flow result for SARS-CoV-2 during the study period. The primary outcome was the likelihood of developing a given symptom (of the 32 monitored in the app) or hospital admission within 7 days before or after the positive test in participants infected during omicron prevalence compared with those infected during delta prevalence. FINDINGS: Between June 1, 2021, and Jan 17, 2022, we identified 63 002 participants who tested positive for SARS-CoV-2 and reported symptoms in the ZOE app. These patients were matched 1:1 for age, sex, and vaccination dose, across two periods (June 1 to Nov 27, 2021, delta prevalent at >70%; n=4990, and Dec 20, 2021, to Jan 17, 2022, omicron prevalent at >70%; n=4990). Loss of smell was less common in participants infected during omicron prevalence than during delta prevalence (16·7% vs 52·7%, odds ratio [OR] 0·17; 95% CI 0·16-0·19, p<0·001). Sore throat was more common during omicron prevalence than during delta prevalence (70·5% vs 60·8%, 1·55; 1·43-1·69, p<0·001). There was a lower rate of hospital admission during omicron prevalence than during delta prevalence (1·9% vs 2·6%, OR 0·75; 95% CI 0·57-0·98, p=0·03). INTERPRETATION: The prevalence of symptoms that characterise an omicron infection differs from those of the delta SARS-CoV-2 variant, apparently with less involvement of the lower respiratory tract and reduced probability of hospital admission. Our data indicate a shorter period of illness and potentially of infectiousness which should impact work-health policies and public health advice. FUNDING: Wellcome Trust, ZOE, National Institute for Health Research, Chronic Disease Research Foundation, National Institutes of Health, and Medical Research Council.

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Metadata

Authors
Menni, C., Valdes, A. M., Polidori, L., Antonelli, M., Penamakuri, S., Nogal, A., Louca, P., May, A., Figueiredo, J. C., Hu, C., Molteni, E., Canas, L., Österdahl, M. F., Modat, M., Sudre, C. H., Fox, B., Hammers, A., Wolf, J., Capdevila, J., Chan, A. T., David, S. P., Steves, C. J., Ourselin, S., & Spector, T. D.
Venue
The Lancet
Publisher
Elsevier BV
Published
2022-04
Volume
399
Issue
10335
Pages
1618-1624
ISSN
  • 0099-5355 (ISSN-L)
  • 0140-6736
OpenAlex
W4223603433
Cited by
854
References
18
FWCI
93.45
Type
journal article
Language
en
Open access
hybrid

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CoChat. (2026). Citation check: Symptom prevalence, duration, and risk of hospital admission in individuals infected with SARS-CoV-2 during periods of omicron and delta variant dominance: a prospective observational study from the ZOE COVID Study. https://app.cochat.ai/papers/10.1016/s0140-6736(22)00327-0
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Menni, C., Valdes, A. M., Polidori, L., Antonelli, M., Penamakuri, S., Nogal, A., Louca, P., May, A., Figueiredo, J. C., Hu, C., Molteni, E., Canas, L., Österdahl, M. F., Modat, M., Sudre, C. H., Fox, B., Hammers, A., Wolf, J., Capdevila, J., . . . Spector, T. D. (2022). Symptom prevalence, duration, and risk of hospital admission in individuals infected with SARS-CoV-2 during periods of omicron and delta variant dominance: a prospective observational study from the ZOE COVID Study. The Lancet. https://doi.org/10.1016/s0140-6736(22)00327-0

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Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

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