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
T2 - a prospective observational cohort study
AU - The COVID-19 Genomics U. K. (COG-UK) Consortium
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 - Bayzid, Nadua
N1 - Publisher Copyright:
© 2022, The Author(s).
PY - 2022/12
Y1 - 2022/12
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.
UR - https://www.scopus.com/pages/publications/85133106586
U2 - 10.1038/s41598-022-14016-0
DO - 10.1038/s41598-022-14016-0
M3 - Artículo
C2 - 35764879
AN - SCOPUS:85133106586
SN - 2045-2322
VL - 12
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 10904
ER -
SDG 3 Good Health and Well-being