SARS-CoV-2 testing and sequencing for international arrivals reveals significant cross border transmission of high risk variants into the United Kingdom

Background: Mandatory Day 2 and Day 8 PCR testing and variant sequencing of international arrivals has been recently introduced by the UK Government to mitigate against cross-border transmission of high-risk SARS-CoV-2 variants. Methods: SARS-CoV-2 testing and sequencing combines TaqPath CE-IVD COVI...

Full description

Bibliographic Details
Main Authors: Gareth H Williams, Alexander Llewelyn, Ruben Brandao, Kaiya Chowdhary, Keeda-Marie Hardisty, Marco Loddo
Format: Article
Language:English
Published: Elsevier 2021-08-01
Series:EClinicalMedicine
Online Access:http://www.sciencedirect.com/science/article/pii/S2589537021003011
_version_ 1818353875189497856
author Gareth H Williams
Alexander Llewelyn
Ruben Brandao
Kaiya Chowdhary
Keeda-Marie Hardisty
Marco Loddo
author_facet Gareth H Williams
Alexander Llewelyn
Ruben Brandao
Kaiya Chowdhary
Keeda-Marie Hardisty
Marco Loddo
author_sort Gareth H Williams
collection DOAJ
description Background: Mandatory Day 2 and Day 8 PCR testing and variant sequencing of international arrivals has been recently introduced by the UK Government to mitigate against cross-border transmission of high-risk SARS-CoV-2 variants. Methods: SARS-CoV-2 testing and sequencing combines TaqPath CE-IVD COVID-19 RT-PCR with Ion AmpliSeq SARS-CoV-2 Next Generation Sequencing Assay. Retrospective analysis of test trending data was performed from initiation of testing on the 11th March through to the 14th April 2021. Findings: During this time interval, 203,065 SARS-CoV-2 PCR tests were performed, with 3,855 samples testing positive, giving a prevalence of 1.9%. In total 1,913 SARS-CoV-2 genomes were sequenced from positive cases with Ct values < 30 and 1,635 (85.5%) sequences passed quality metrics for lineage analysis. A high diversity of 49 different SARS-CoV-2 variants were identified, including the VOCs B.1.1.7 (Kent; 80.6%), B.1.351 (South Africa; 4.2%), B.1.617.2 (India; 1.7%), P.1 (Brazil; 0.4%) and B.1.1.7 with E484K (Bristol; 0.2%). Vaccine effectiveness was age-related and dose-dependent, ranging from 5% in > 60 with a single dose to 83% in <60 with both doses of a vaccine. Viral load was variant dependent with the B.1.617.2 showing a 21 fold increase in viral copy number compared to the other variants. Interpretation: The unexpectedly high prevalence of COVID-19 infection in UK arrivals is associated with a rich diversity of SARS-CoV-2 high risk variants entering the UK including the VOC B.1.617.2. Vaccination does not preclude infection and its effectiveness is significantly age-dependent and impacted by variant type. The rapid high-throughput test and sequence workflow we have adopted is particularly suited to the monitoring of cross border transmission and enables immediate public health interventions. Funding: Data analysis conducted in this study was limited to secondary use of information previously collected in the course of normal care.
first_indexed 2024-12-13T19:16:28Z
format Article
id doaj.art-62e8497b84ce4af49676fafdb5b49b98
institution Directory Open Access Journal
issn 2589-5370
language English
last_indexed 2024-12-13T19:16:28Z
publishDate 2021-08-01
publisher Elsevier
record_format Article
series EClinicalMedicine
spelling doaj.art-62e8497b84ce4af49676fafdb5b49b982022-12-21T23:34:16ZengElsevierEClinicalMedicine2589-53702021-08-0138101021SARS-CoV-2 testing and sequencing for international arrivals reveals significant cross border transmission of high risk variants into the United KingdomGareth H Williams0Alexander Llewelyn1Ruben Brandao2Kaiya Chowdhary3Keeda-Marie Hardisty4Marco Loddo5Oncologica UK Ltd. Suite 2, The Newnham Building, Chesterford Research Park, Cambridge CB10 1XL, United KingdomOncologica UK Ltd. Suite 2, The Newnham Building, Chesterford Research Park, Cambridge CB10 1XL, United KingdomOncologica UK Ltd. Suite 2, The Newnham Building, Chesterford Research Park, Cambridge CB10 1XL, United KingdomOncologica UK Ltd. Suite 2, The Newnham Building, Chesterford Research Park, Cambridge CB10 1XL, United KingdomOncologica UK Ltd. Suite 2, The Newnham Building, Chesterford Research Park, Cambridge CB10 1XL, United Kingdom; Corresponding author.Oncologica UK Ltd. Suite 2, The Newnham Building, Chesterford Research Park, Cambridge CB10 1XL, United KingdomBackground: Mandatory Day 2 and Day 8 PCR testing and variant sequencing of international arrivals has been recently introduced by the UK Government to mitigate against cross-border transmission of high-risk SARS-CoV-2 variants. Methods: SARS-CoV-2 testing and sequencing combines TaqPath CE-IVD COVID-19 RT-PCR with Ion AmpliSeq SARS-CoV-2 Next Generation Sequencing Assay. Retrospective analysis of test trending data was performed from initiation of testing on the 11th March through to the 14th April 2021. Findings: During this time interval, 203,065 SARS-CoV-2 PCR tests were performed, with 3,855 samples testing positive, giving a prevalence of 1.9%. In total 1,913 SARS-CoV-2 genomes were sequenced from positive cases with Ct values < 30 and 1,635 (85.5%) sequences passed quality metrics for lineage analysis. A high diversity of 49 different SARS-CoV-2 variants were identified, including the VOCs B.1.1.7 (Kent; 80.6%), B.1.351 (South Africa; 4.2%), B.1.617.2 (India; 1.7%), P.1 (Brazil; 0.4%) and B.1.1.7 with E484K (Bristol; 0.2%). Vaccine effectiveness was age-related and dose-dependent, ranging from 5% in > 60 with a single dose to 83% in <60 with both doses of a vaccine. Viral load was variant dependent with the B.1.617.2 showing a 21 fold increase in viral copy number compared to the other variants. Interpretation: The unexpectedly high prevalence of COVID-19 infection in UK arrivals is associated with a rich diversity of SARS-CoV-2 high risk variants entering the UK including the VOC B.1.617.2. Vaccination does not preclude infection and its effectiveness is significantly age-dependent and impacted by variant type. The rapid high-throughput test and sequence workflow we have adopted is particularly suited to the monitoring of cross border transmission and enables immediate public health interventions. Funding: Data analysis conducted in this study was limited to secondary use of information previously collected in the course of normal care.http://www.sciencedirect.com/science/article/pii/S2589537021003011
spellingShingle Gareth H Williams
Alexander Llewelyn
Ruben Brandao
Kaiya Chowdhary
Keeda-Marie Hardisty
Marco Loddo
SARS-CoV-2 testing and sequencing for international arrivals reveals significant cross border transmission of high risk variants into the United Kingdom
EClinicalMedicine
title SARS-CoV-2 testing and sequencing for international arrivals reveals significant cross border transmission of high risk variants into the United Kingdom
title_full SARS-CoV-2 testing and sequencing for international arrivals reveals significant cross border transmission of high risk variants into the United Kingdom
title_fullStr SARS-CoV-2 testing and sequencing for international arrivals reveals significant cross border transmission of high risk variants into the United Kingdom
title_full_unstemmed SARS-CoV-2 testing and sequencing for international arrivals reveals significant cross border transmission of high risk variants into the United Kingdom
title_short SARS-CoV-2 testing and sequencing for international arrivals reveals significant cross border transmission of high risk variants into the United Kingdom
title_sort sars cov 2 testing and sequencing for international arrivals reveals significant cross border transmission of high risk variants into the united kingdom
url http://www.sciencedirect.com/science/article/pii/S2589537021003011
work_keys_str_mv AT garethhwilliams sarscov2testingandsequencingforinternationalarrivalsrevealssignificantcrossbordertransmissionofhighriskvariantsintotheunitedkingdom
AT alexanderllewelyn sarscov2testingandsequencingforinternationalarrivalsrevealssignificantcrossbordertransmissionofhighriskvariantsintotheunitedkingdom
AT rubenbrandao sarscov2testingandsequencingforinternationalarrivalsrevealssignificantcrossbordertransmissionofhighriskvariantsintotheunitedkingdom
AT kaiyachowdhary sarscov2testingandsequencingforinternationalarrivalsrevealssignificantcrossbordertransmissionofhighriskvariantsintotheunitedkingdom
AT keedamariehardisty sarscov2testingandsequencingforinternationalarrivalsrevealssignificantcrossbordertransmissionofhighriskvariantsintotheunitedkingdom
AT marcoloddo sarscov2testingandsequencingforinternationalarrivalsrevealssignificantcrossbordertransmissionofhighriskvariantsintotheunitedkingdom