COVID-19 due to the B.1.617.2 (Delta) variant compared to B.1.1.7 (Alpha) variant of SARS-CoV-2: a prospective observational cohort study: a prospective observational cohort study

Kerstin Kläser; Erika Molteni; Mark Graham; Liane S. Canas; Marc F. Österdahl; Michela Antonelli; Liyuan Chen; Jie Deng; Benjamin Murray; Eric Kerfoot; Jonathan Wolf; Anna May; Ben Fox; Joan Capdevila; David M. Aanensen; Khalil Abudahab; Helen Adams; Alexander Adams; Safiah Afifi; Dinesh Aggarwal; Shazaad S.Y. Ahmad; Louise Aigrain; Adela Alcolea-Medina; Nabil Fareed Alikhan; Elias Allara; Roberto Amato; Adrienn Angyal; Tara Annett; Stephen Aplin; Cristina V. Ariani; Hibo Asad; Amy Ash; Paula Ashfield; Fiona Ashford; Laura Atkinson; Stephen W. Attwood; Cressida Auckland; Alp Aydin; David J. Baker; Paul Baker; Carlos E. Balcazar; Jonathan Ball; Jeffrey C. Barrett; Magdalena Barrow; Edward Barton; Matthew Bashton; Andrew R. Bassett; Rahul Batra; Chris Baxter; Sally Forrest

doi:10.1038/s41598-022-14016-0

COVID-19 due to the B.1.617.2 (Delta) variant compared to B.1.1.7 (Alpha) variant of SARS-CoV-2: a prospective observational cohort study: a prospective observational cohort study

Kerstin Kläser
, Erika Molteni
, Mark Graham
, Liane S. Canas
, Marc F. Österdahl
, Michela Antonelli
, Liyuan Chen
, Jie Deng
, Benjamin Murray
, Eric Kerfoot
, Jonathan Wolf
, Anna May
, Ben Fox
, Joan Capdevila
, David M. Aanensen
, Khalil Abudahab
, Helen Adams
, Alexander Adams
, Safiah Afifi
, Dinesh Aggarwal

Shazaad S.Y. Ahmad, Louise Aigrain, Adela Alcolea-Medina, Nabil Fareed Alikhan, Elias Allara, Roberto Amato, Adrienn Angyal, Tara Annett, Stephen Aplin, Cristina V. Ariani, Hibo Asad, Amy Ash, Paula Ashfield, Fiona Ashford, Laura Atkinson, Stephen W. Attwood, Cressida Auckland, Alp Aydin, David J. Baker, Paul Baker, Carlos E. Balcazar, Jonathan Ball, Jeffrey C. Barrett, Magdalena Barrow, Edward Barton, Matthew Bashton, Andrew R. Bassett, Rahul Batra, Chris Baxter, Sally Forrest

King's College London
St Thomas' Hospital
Guy's and St Thomas' NHS Foundation Trust
Zoe Global Limited
University of Oxford
Betsi Cadwaladr University Health Board
Public Health Wales
Cardiff & Vale University Health Board
University of Cambridge
Manchester University NHS Foundation Trust
Wellcome Sanger Institute
Quadram Institute
UK Health Security Agency
University of Sheffield
University Hospital Southampton NHS Foundation Trust
Barking, Havering and Redbridge University Hospitals NHS Trust
Royal Wolverhampton Hospitals NHS Trust
University of Birmingham
Great Ormond Street Hospital for Children NHS Foundation Trust
Royal Devon & Exeter NHS Foundation Trust
South Tees Hospitals NHS Foundation Trust
University of Edinburgh
University of Nottingham
Bournemouth University
North Cumbria Integrated Care NHS Foundation Trust
Northumbria University
Queen's University Belfast

Research output: Contribution to journal › Article › peer-review

48 Citations (Scopus)

Abstract

The Delta (B.1.617.2) variant was the predominant UK circulating SARS-CoV-2 strain between May and December 2021. How Delta infection compares with previous variants is unknown. This prospective observational cohort study assessed symptomatic adults participating in the app-based COVID Symptom Study who tested positive for SARS-CoV-2 from May 26 to July 1, 2021 (Delta overwhelmingly the predominant circulating UK variant), compared (1:1, age- and sex-matched) with individuals presenting from December 28, 2020 to May 6, 2021 (Alpha (B.1.1.7) the predominant variant). We assessed illness (symptoms, duration, presentation to hospital) during Alpha- and Delta-predominant timeframes; and transmission, reinfection, and vaccine effectiveness during the Delta-predominant period. 3581 individuals (aged 18 to 100 years) from each timeframe were assessed. The seven most frequent symptoms were common to both variants. Within the first 28 days of illness, some symptoms were more common with Delta versus Alpha infection (including fever, sore throat, and headache) and some vice versa (dyspnoea). Symptom burden in the first week was higher with Delta versus Alpha infection; however, the odds of any given symptom lasting ≥ 7 days was either lower or unchanged. Illness duration ≥ 28 days was lower with Delta versus Alpha infection, though unchanged in unvaccinated individuals. Hospitalisation for COVID-19 was unchanged. The Delta variant appeared more (1.49) transmissible than Alpha. Re-infections were low in all UK regions. Vaccination markedly reduced the risk of Delta infection (by 69-84%). We conclude that COVID-19 from Delta or Alpha infections is similar. The Delta variant is more transmissible than Alpha; however, current vaccines showed good efficacy against disease. This research framework can be useful for future comparisons with new emerging variants.

Original language	English
Article number	10904
Journal	Scientific Reports
Volume	12
Issue number	1
DOIs	https://doi.org/10.1038/s41598-022-14016-0
Publication status	Published - 1 Dec 2022
Externally published	Yes

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 3 Good Health and Well-being

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Cite this

Kläser, K., Molteni, E., Graham, M., Canas, L. S., Österdahl, M. F., Antonelli, M., Chen, L., Deng, J., Murray, B., Kerfoot, E., Wolf, J., May, A., Fox, B., Capdevila, J., Aanensen, D. M., Abudahab, K., Adams, H., Adams, A., Afifi, S., ... Forrest, S. (2022). COVID-19 due to the B.1.617.2 (Delta) variant compared to B.1.1.7 (Alpha) variant of SARS-CoV-2: a prospective observational cohort study: a prospective observational cohort study. Scientific Reports, 12(1), Article 10904. https://doi.org/10.1038/s41598-022-14016-0

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title = "COVID-19 due to the B.1.617.2 (Delta) variant compared to B.1.1.7 (Alpha) variant of SARS-CoV-2: a prospective observational cohort study: a prospective observational cohort study",

abstract = "The Delta (B.1.617.2) variant was the predominant UK circulating SARS-CoV-2 strain between May and December 2021. How Delta infection compares with previous variants is unknown. This prospective observational cohort study assessed symptomatic adults participating in the app-based COVID Symptom Study who tested positive for SARS-CoV-2 from May 26 to July 1, 2021 (Delta overwhelmingly the predominant circulating UK variant), compared (1:1, age- and sex-matched) with individuals presenting from December 28, 2020 to May 6, 2021 (Alpha (B.1.1.7) the predominant variant). We assessed illness (symptoms, duration, presentation to hospital) during Alpha- and Delta-predominant timeframes; and transmission, reinfection, and vaccine effectiveness during the Delta-predominant period. 3581 individuals (aged 18 to 100 years) from each timeframe were assessed. The seven most frequent symptoms were common to both variants. Within the first 28 days of illness, some symptoms were more common with Delta versus Alpha infection (including fever, sore throat, and headache) and some vice versa (dyspnoea). Symptom burden in the first week was higher with Delta versus Alpha infection; however, the odds of any given symptom lasting ≥ 7 days was either lower or unchanged. Illness duration ≥ 28 days was lower with Delta versus Alpha infection, though unchanged in unvaccinated individuals. Hospitalisation for COVID-19 was unchanged. The Delta variant appeared more (1.49) transmissible than Alpha. Re-infections were low in all UK regions. Vaccination markedly reduced the risk of Delta infection (by 69-84\%). We conclude that COVID-19 from Delta or Alpha infections is similar. The Delta variant is more transmissible than Alpha; however, current vaccines showed good efficacy against disease. This research framework can be useful for future comparisons with new emerging variants.",

author = "Kerstin Kl{\"a}ser and Erika Molteni and Mark Graham and Canas, \{Liane S.\} and {\"O}sterdahl, \{Marc F.\} and Michela Antonelli and Liyuan Chen and Jie Deng and Benjamin Murray and Eric Kerfoot and Jonathan Wolf and Anna May and Ben Fox and Joan Capdevila and Aanensen, \{David M.\} and Khalil Abudahab and Helen Adams and Alexander Adams and Safiah Afifi and Dinesh Aggarwal and Ahmad, \{Shazaad S.Y.\} and Louise Aigrain and Adela Alcolea-Medina and Alikhan, \{Nabil Fareed\} and Elias Allara and Roberto Amato and Adrienn Angyal and Tara Annett and Stephen Aplin and Ariani, \{Cristina V.\} and Hibo Asad and Amy Ash and Paula Ashfield and Fiona Ashford and Laura Atkinson and Attwood, \{Stephen W.\} and Cressida Auckland and Alp Aydin and Baker, \{David J.\} and Paul Baker and Balcazar, \{Carlos E.\} and Jonathan Ball and Barrett, \{Jeffrey C.\} and Magdalena Barrow and Edward Barton and Matthew Bashton and Bassett, \{Andrew R.\} and Rahul Batra and Chris Baxter and Sally Forrest",

year = "2022",

month = dec,

day = "1",

doi = "10.1038/s41598-022-14016-0",

language = "English",

volume = "12",

journal = "Scientific Reports",

issn = "2045-2322",

publisher = "Nature Research",

number = "1",

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Kläser, K, Molteni, E, Graham, M, Canas, LS, Österdahl, MF, Antonelli, M, Chen, L, Deng, J, Murray, B, Kerfoot, E, Wolf, J, May, A, Fox, B, Capdevila, J, Aanensen, DM, Abudahab, K, Adams, H, Adams, A, Afifi, S, Aggarwal, D, Ahmad, SSY, Aigrain, L, Alcolea-Medina, A, Alikhan, NF, Allara, E, Amato, R, Angyal, A, Annett, T, Aplin, S, Ariani, CV, Asad, H, Ash, A, Ashfield, P, Ashford, F, Atkinson, L, Attwood, SW, Auckland, C, Aydin, A, Baker, DJ, Baker, P, Balcazar, CE, Ball, J, Barrett, JC, Barrow, M, Barton, E, Bashton, M, Bassett, AR, Batra, R, Baxter, C & Forrest, S 2022, 'COVID-19 due to the B.1.617.2 (Delta) variant compared to B.1.1.7 (Alpha) variant of SARS-CoV-2: a prospective observational cohort study: a prospective observational cohort study', Scientific Reports, vol. 12, no. 1, 10904. https://doi.org/10.1038/s41598-022-14016-0

TY - JOUR

T1 - COVID-19 due to the B.1.617.2 (Delta) variant compared to B.1.1.7 (Alpha) variant of SARS-CoV-2: a prospective observational cohort study: a prospective observational cohort study

AU - Kläser, Kerstin

AU - Molteni, Erika

AU - Graham, Mark

AU - Canas, Liane S.

AU - Österdahl, Marc F.

AU - Antonelli, Michela

AU - Chen, Liyuan

AU - Deng, Jie

AU - Murray, Benjamin

AU - Kerfoot, Eric

AU - Wolf, Jonathan

AU - May, Anna

AU - Fox, Ben

AU - Capdevila, Joan

AU - Aanensen, David M.

AU - Abudahab, Khalil

AU - Adams, Helen

AU - Adams, Alexander

AU - Afifi, Safiah

AU - Aggarwal, Dinesh

AU - Ahmad, Shazaad S.Y.

AU - Aigrain, Louise

AU - Alcolea-Medina, Adela

AU - Alikhan, Nabil Fareed

AU - Allara, Elias

AU - Amato, Roberto

AU - Angyal, Adrienn

AU - Annett, Tara

AU - Aplin, Stephen

AU - Ariani, Cristina V.

AU - Asad, Hibo

AU - Ash, Amy

AU - Ashfield, Paula

AU - Ashford, Fiona

AU - Atkinson, Laura

AU - Attwood, Stephen W.

AU - Auckland, Cressida

AU - Aydin, Alp

AU - Baker, David J.

AU - Baker, Paul

AU - Balcazar, Carlos E.

AU - Ball, Jonathan

AU - Barrett, Jeffrey C.

AU - Barrow, Magdalena

AU - Barton, Edward

AU - Bashton, Matthew

AU - Bassett, Andrew R.

AU - Batra, Rahul

AU - Baxter, Chris

AU - Forrest, Sally

PY - 2022/12/1

Y1 - 2022/12/1

N2 - The Delta (B.1.617.2) variant was the predominant UK circulating SARS-CoV-2 strain between May and December 2021. How Delta infection compares with previous variants is unknown. This prospective observational cohort study assessed symptomatic adults participating in the app-based COVID Symptom Study who tested positive for SARS-CoV-2 from May 26 to July 1, 2021 (Delta overwhelmingly the predominant circulating UK variant), compared (1:1, age- and sex-matched) with individuals presenting from December 28, 2020 to May 6, 2021 (Alpha (B.1.1.7) the predominant variant). We assessed illness (symptoms, duration, presentation to hospital) during Alpha- and Delta-predominant timeframes; and transmission, reinfection, and vaccine effectiveness during the Delta-predominant period. 3581 individuals (aged 18 to 100 years) from each timeframe were assessed. The seven most frequent symptoms were common to both variants. Within the first 28 days of illness, some symptoms were more common with Delta versus Alpha infection (including fever, sore throat, and headache) and some vice versa (dyspnoea). Symptom burden in the first week was higher with Delta versus Alpha infection; however, the odds of any given symptom lasting ≥ 7 days was either lower or unchanged. Illness duration ≥ 28 days was lower with Delta versus Alpha infection, though unchanged in unvaccinated individuals. Hospitalisation for COVID-19 was unchanged. The Delta variant appeared more (1.49) transmissible than Alpha. Re-infections were low in all UK regions. Vaccination markedly reduced the risk of Delta infection (by 69-84%). We conclude that COVID-19 from Delta or Alpha infections is similar. The Delta variant is more transmissible than Alpha; however, current vaccines showed good efficacy against disease. This research framework can be useful for future comparisons with new emerging variants.

AB - The Delta (B.1.617.2) variant was the predominant UK circulating SARS-CoV-2 strain between May and December 2021. How Delta infection compares with previous variants is unknown. This prospective observational cohort study assessed symptomatic adults participating in the app-based COVID Symptom Study who tested positive for SARS-CoV-2 from May 26 to July 1, 2021 (Delta overwhelmingly the predominant circulating UK variant), compared (1:1, age- and sex-matched) with individuals presenting from December 28, 2020 to May 6, 2021 (Alpha (B.1.1.7) the predominant variant). We assessed illness (symptoms, duration, presentation to hospital) during Alpha- and Delta-predominant timeframes; and transmission, reinfection, and vaccine effectiveness during the Delta-predominant period. 3581 individuals (aged 18 to 100 years) from each timeframe were assessed. The seven most frequent symptoms were common to both variants. Within the first 28 days of illness, some symptoms were more common with Delta versus Alpha infection (including fever, sore throat, and headache) and some vice versa (dyspnoea). Symptom burden in the first week was higher with Delta versus Alpha infection; however, the odds of any given symptom lasting ≥ 7 days was either lower or unchanged. Illness duration ≥ 28 days was lower with Delta versus Alpha infection, though unchanged in unvaccinated individuals. Hospitalisation for COVID-19 was unchanged. The Delta variant appeared more (1.49) transmissible than Alpha. Re-infections were low in all UK regions. Vaccination markedly reduced the risk of Delta infection (by 69-84%). We conclude that COVID-19 from Delta or Alpha infections is similar. The Delta variant is more transmissible than Alpha; however, current vaccines showed good efficacy against disease. This research framework can be useful for future comparisons with new emerging variants.

U2 - 10.1038/s41598-022-14016-0

DO - 10.1038/s41598-022-14016-0

M3 - Article

SN - 2045-2322

VL - 12

JO - Scientific Reports

JF - Scientific Reports

IS - 1

M1 - 10904

ER -

COVID-19 due to the B.1.617.2 (Delta) variant compared to B.1.1.7 (Alpha) variant of SARS-CoV-2: a prospective observational cohort study: a prospective observational cohort study

Abstract

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