Imperial College London
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ProfessorHelenWard

Faculty of Medicine, School of Public Health

Professor of Public Health
 
 
 
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Contact

 

+44 (0)20 7594 3303h.ward Website

 
 
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Location

 

311School of Public HealthWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@unpublished{Chadeau-Hyam:2021,
author = {Chadeau-Hyam, M and Eales, O and Bodinier, B and Wang, H and Haw, D and Whitaker, M and Walters, C and Jonnerby, J and Atchison, C and Diggle, P and Page, A and Ashby, D and Barclay, W and Taylor, G and Cooke, G and Ward, H and Darzi, A and Donnelly, C and Elliott, P},
title = {REACT-1 round 15 final report: Increased breakthrough SARS-CoV-2 infections among adults who had received two doses of vaccine, but booster doses and first doses in children are providing important protection},
url = {http://hdl.handle.net/10044/1/92501},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - UNPB
AB  - Background: It has been nearly a year since the first vaccinations against SARS-CoV-2were delivered in England. The third wave of COVID-19 in England began in May 2021 asthe Delta variant began to outcompete and largely replace other strains. The REal-timeAssessment of Community Transmission-1 (REACT-1) series of community surveys forSARS-CoV-2 infection has provided insights into transmission dynamics since May 2020.Round 15 of the REACT-1 study was carried out from 19 October to 5 November 2021.Methods: We estimated prevalence of SARS-CoV2 infection and used multiple logisticregression to analyse associations between SARS-CoV-2 infection in England anddemographic and other risk factors, based on RT-PCR results from self-administered throatand nose swabs in over 100,000 participants. We estimated (single-dose) vaccineeffectiveness among children aged 12 to 17 years, and among adults comparedswab-positivity in people who had received a third (booster) dose with those who hadreceived two vaccine doses. We used splines to analyse time trends in swab-positivity.Results: During mid-October to early-November 2021, weighted prevalence was 1.57%(1.48%, 1.66%) compared to 0.83% (0.76%, 0.89%) in September 2021 (round 14).Weighted prevalence increased between rounds 14 and 15 across most age groups(including older ages, 65 years and over) and regions, with average reproduction numberacross rounds of R=1.09 (1.08, 1.11). During round 15, there was a fall in prevalence from amaximum around 20-21 October, with an R of 0.76 (0.70, 0.83), reflecting falls in prevalenceat ages 17 years and below and 18 to 54 years. School-aged children had the highestweighted prevalence of infection: 4.95% (4.39%, 5.58%) in those aged 5 to 12 years and5.21% (4.61%, 5.87%) in those aged 13 to 17 years. In multiple logistic regression, age, sex,key worker status and presence of one or more children in the home were associated withswab positivity. There was evidence of heterogeneity between rounds in
AU  - Chadeau-Hyam,M
AU  - Eales,O
AU  - Bodinier,B
AU  - Wang,H
AU  - Haw,D
AU  - Whitaker,M
AU  - Walters,C
AU  - Jonnerby,J
AU  - Atchison,C
AU  - Diggle,P
AU  - Page,A
AU  - Ashby,D
AU  - Barclay,W
AU  - Taylor,G
AU  - Cooke,G
AU  - Ward,H
AU  - Darzi,A
AU  - Donnelly,C
AU  - Elliott,P
PY  - 2021///
TI  - REACT-1 round 15 final report: Increased breakthrough SARS-CoV-2 infections among adults who had received two doses of vaccine, but booster doses and first doses in children are providing important protection
UR  - http://hdl.handle.net/10044/1/92501
ER  -
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