| Literature DB >> 34726481 |
David Haw1,2, Haowei Wang1,2, Oliver Eales1,2, Paul Elliott1,3,4,5,6,7, Caroline E Walters1,2, Kylie E C Ainslie1,2,8, Christina Atchison1, Claudio Fronterre9, Peter J Diggle9, Andrew J Page10, Alexander J Trotter10, Sophie J Prosolek10, Deborah Ashby1, Christl A Donnelly1,2,11, Wendy Barclay12, Graham Taylor12, Graham Cooke3,4,12, Helen Ward1,3,4, Ara Darzi3,4,13,14, Steven Riley1,2.
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections were rising during early summer 2021 in many countries as a result of the Delta variant. We assessed reverse transcription polymerase chain reaction swab positivity in the Real-time Assessment of Community Transmission–1 (REACT-1) study in England. During June and July 2021, we observed sustained exponential growth with an average doubling time of 25 days, driven by complete replacement of the Alpha variant by Delta and by high prevalence at younger, less-vaccinated ages. Prevalence among unvaccinated people [1.21% (95% credible interval 1.03%, 1.41%)] was three times that among double-vaccinated people [0.40% (95% credible interval 0.34%, 0.48%)]. However, after adjusting for age and other variables, vaccine effectiveness for double-vaccinated people was estimated at between ~50% and ~60% during this period in England. Increased social mixing in the presence of Delta had the potential to generate sustained growth in infections, even at high levels of vaccination.Entities:
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Year: 2021 PMID： 34726481 DOI： 10.1126/science.abl9551
Source DB: PubMed Journal: Science ISSN： 0036-8075 Impact factor: 47.728