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Powell AA, Dowell AC, Moss P, Ladhani SN. Current state of COVID-19 in children: 4 years on. J Infect 2024; 88:106134. [PMID: 38432584 DOI: 10.1016/j.jinf.2024.106134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 02/28/2024] [Indexed: 03/05/2024]
Abstract
Children have been disproportionately affected by the COVID-19 pandemic. Despite evidence of a very low risk of severe disease, children were subjected to extensive lockdown, restriction and mitigation measures, including school closures, to control the rapid spread of SARS-CoV-2 in most parts of the world. In this review we summarise the UK experience of COVID-19 in children four years into the largest and longest pandemic of this century. We address the risks of SARS-CoV-2 infection, immunity, transmission, severity and outcomes in children. We also assess the implementation, uptake, effectiveness and impact of COVID-19 vaccination, as well as the emergence, evolution and near disappearance of PIMS-TS (paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2) and current understanding of long COVID in children. This review consolidates current knowledge on childhood COVID-19 and emphasises the importance of continued research and the need for research-driven public health actions and policy decisions, especially in the context of new variants and future vaccines.
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Affiliation(s)
- Annabel A Powell
- Public Health Programmes, UK Health Security Agency, London, UK.
| | - Alexander C Dowell
- Institute of Immunology & Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Paul Moss
- Institute of Immunology & Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Shamez N Ladhani
- Public Health Programmes, UK Health Security Agency, London, UK; Paediatric Infectious Diseases Research Group, St. George's University of London, London, UK
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2
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Muhsen K, Waight PA, Kirsebom F, Andrews N, Letley L, Gower CM, Skarnes C, Quinot C, Lunt R, Bernal JL, Flasche S, Miller E. Association between COVID-19 Vaccination and SARS-CoV-2 Infection among Household Contacts of Infected Individuals: A Prospective Household Study in England. Vaccines (Basel) 2024; 12:113. [PMID: 38400097 PMCID: PMC10892628 DOI: 10.3390/vaccines12020113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/07/2024] [Accepted: 01/18/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND We investigated whether COVID-19 vaccination reduced SARS-CoV-2 infection risk among adult household contacts of COVID-19 index cases during the Alpha, Delta, and Omicron waves in England. METHODS Between February 2021 and February 2022, SARS-CoV-2 RT-PCR nasal swabs were collected from COVID-19-confirmed index cases aged ≥20 years and their household contacts at enrolment and three and seven days thereafter. Generalized Estimating Equations models were fitted with SARS-CoV-2 positivity as the outcome and household contacts' vaccination status as the main exposure while adjusting for confounders. RESULTS SARS-CoV-2 infection was confirmed in 238/472 household contacts (50.4%) aged ≥20 years. The adjusted relative risk (95% confidence interval) of infection in vaccinated versus unvaccinated household contacts was 0.50 (0.35-0.72) and 0.69 (0.53-0.90) for receipt of two doses 8-90 and >90 days ago, respectively, and 0.34 (0.23-0.50) for vaccination with three doses 8-151 days ago. Primary vaccination protected household contacts against infection during the Alpha and Delta waves, but only three doses protected during the Omicron wave. Vaccination with three doses in the index case independently reduced contacts' infection risk: 0.45 (0.23-0.89). CONCLUSIONS Vaccination of household contacts reduces their risk of infection under conditions of household exposure though, for Omicron, only after a booster dose.
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Affiliation(s)
- Khitam Muhsen
- Department of Epidemiology and Preventive Medicine, School of Public Health, Faculty of Medicine, Tel Aviv University, Tel Aviv 6139001, Israel
- London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK; (S.F.); (E.M.)
| | - Pauline A. Waight
- UK Health Security Agency, 61 Colindale Avenue, London NW9 5EU, UK; (P.A.W.); (F.K.); (N.A.); (C.S.); (J.L.B.)
| | - Freja Kirsebom
- UK Health Security Agency, 61 Colindale Avenue, London NW9 5EU, UK; (P.A.W.); (F.K.); (N.A.); (C.S.); (J.L.B.)
| | - Nick Andrews
- UK Health Security Agency, 61 Colindale Avenue, London NW9 5EU, UK; (P.A.W.); (F.K.); (N.A.); (C.S.); (J.L.B.)
| | - Louise Letley
- UK Health Security Agency, 61 Colindale Avenue, London NW9 5EU, UK; (P.A.W.); (F.K.); (N.A.); (C.S.); (J.L.B.)
| | - Charlotte M. Gower
- UK Health Security Agency, 61 Colindale Avenue, London NW9 5EU, UK; (P.A.W.); (F.K.); (N.A.); (C.S.); (J.L.B.)
| | - Catriona Skarnes
- UK Health Security Agency, 61 Colindale Avenue, London NW9 5EU, UK; (P.A.W.); (F.K.); (N.A.); (C.S.); (J.L.B.)
| | - Catherine Quinot
- UK Health Security Agency, 61 Colindale Avenue, London NW9 5EU, UK; (P.A.W.); (F.K.); (N.A.); (C.S.); (J.L.B.)
| | - Rachel Lunt
- UK Health Security Agency, 61 Colindale Avenue, London NW9 5EU, UK; (P.A.W.); (F.K.); (N.A.); (C.S.); (J.L.B.)
| | - Jamie Lopez Bernal
- UK Health Security Agency, 61 Colindale Avenue, London NW9 5EU, UK; (P.A.W.); (F.K.); (N.A.); (C.S.); (J.L.B.)
- NIHR Health Protection Research Unit in Respiratory Infections, Imperial College London, London SW7 2AZ, UK
| | - Stefan Flasche
- London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK; (S.F.); (E.M.)
| | - Elizabeth Miller
- London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK; (S.F.); (E.M.)
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Omiyale W, Holliday J, Doherty N, Callen H, Wood N, Horn E, Burnett F, Young A, Lewington S, Fry D, Bešević J, Conroy M, Sheard S, Feng Q, Welsh S, Effingham M, Young A, Collins R, Lacey B, Allen N. Social determinants of ethnic disparities in SARS-CoV-2 infection: UK Biobank SARS-CoV-2 Serology Study. J Epidemiol Community Health 2023; 78:3-10. [PMID: 37699665 PMCID: PMC10715462 DOI: 10.1136/jech-2023-220353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 08/25/2023] [Indexed: 09/14/2023]
Abstract
BACKGROUND The social determinants of ethnic disparities in risk of SARS-CoV-2 infection during the first wave of the pandemic in the UK remain unclear. METHODS In May 2020, a total of 20 195 adults were recruited from the general population into the UK Biobank SARS-CoV-2 Serology Study. Between mid-May and mid-November 2020, participants provided monthly blood samples. At the end of the study, participants completed a questionnaire on social factors during different periods of the pandemic. Logistic regression yielded ORs for the association between ethnicity and SARS-CoV-2 immunoglobulin G antibodies (indicating prior infection) using blood samples collected in July 2020, immediately after the first wave. RESULTS After exclusions, 14 571 participants (mean age 56; 58% women) returned a blood sample in July, of whom 997 (7%) had SARS-CoV-2 antibodies. Seropositivity was strongly related to ethnicity: compared with those of White ethnicity, ORs (adjusted for age and sex) for Black, South Asian, Chinese, Mixed and Other ethnic groups were 2.66 (95% CI 1.94-3.60), 1.66 (1.15-2.34), 0.99 (0.42-1.99), 1.42 (1.03-1.91) and 1.79 (1.27-2.47), respectively. Additional adjustment for social factors reduced the overall likelihood ratio statistics for ethnicity by two-thirds (67%; mostly from occupational factors and UK region of residence); more precise measurement of social factors may have further reduced the association. CONCLUSIONS This study identifies social factors that are likely to account for much of the ethnic disparities in SARS-CoV-2 infection during the first wave in the UK, and highlights the particular relevance of occupation and residential region in the pathway between ethnicity and SARS-CoV-2 infection.
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Affiliation(s)
- Wemimo Omiyale
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Jo Holliday
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- UK Biobank, Stockport, UK
| | | | - Howard Callen
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- UK Biobank, Stockport, UK
| | - Natasha Wood
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- UK Biobank, Stockport, UK
| | - Edward Horn
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- UK Biobank, Stockport, UK
| | - Frances Burnett
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Allen Young
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- UK Biobank, Stockport, UK
| | - Sarah Lewington
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- MRC Population Health Research Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | | | - Jelena Bešević
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Megan Conroy
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | | | - Qi Feng
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | | | | | - Alan Young
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- UK Biobank, Stockport, UK
| | - Rory Collins
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- UK Biobank, Stockport, UK
| | - Ben Lacey
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- UK Biobank, Stockport, UK
| | - Naomi Allen
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- UK Biobank, Stockport, UK
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Clifford S, Waight P, Hackman J, Hué S, Gower CM, Kirsebom FCM, Skarnes C, Letley L, Lopez Bernal J, Andrews N, Flasche S, Miller E. Effectiveness of BNT162b2 and ChAdOx1 against SARS-CoV-2 household transmission: a prospective cohort study in England. Wellcome Open Res 2023; 8:96. [PMID: 38058535 PMCID: PMC10697107 DOI: 10.12688/wellcomeopenres.17995.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2023] [Indexed: 12/08/2023] Open
Abstract
Background The ability of SARS-CoV-2 vaccines to protect against infection and onward transmission determines whether immunisation can control global circulation. We estimated the effectiveness of Pfizer-BioNTech mRNA vaccine (BNT162b2) and Oxford AstraZeneca adenovirus vector vaccine (ChAdOx1) vaccines against acquisition and transmission of the Alpha and Delta variants in a prospective household study in England. Methods Households were recruited based on adult purported index cases testing positive after reverse transcription-quantitative (RT-q)PCR testing of oral-nasal swabs. Purported index cases and their household contacts took oral-nasal swabs on days 1, 3 and 7 after enrolment and a subset of the PCR-positive swabs underwent genomic sequencing conducted on a subset. We used Bayesian logistic regression to infer vaccine effectiveness against acquisition and transmission, adjusted for age, vaccination history and variant. Results Between 2 February 2021 and 10 September 2021, 213 index cases and 312 contacts were followed up. After excluding households lacking genomic proximity (N=2) or with unlikely serial intervals (N=16), 195 households with 278 contacts remained, of whom 113 (41%) became PCR positive. Delta lineages had 1.53 times the risk (95% Credible Interval: 1.04 - 2.20) of transmission than Alpha; contacts older than 18 years old were 1.48 (1.20 - 1.91) and 1.02 (0.93 - 1.16) times more likely to acquire an Alpha or Delta infection than children. Effectiveness of two doses of BNT162b2 against transmission of Delta was 36% (-1%, 66%) and 49% (18%, 73%) for ChAdOx1, similar to their effectiveness for Alpha. Protection against infection with Alpha was higher than for Delta, 69% (9%, 95%) vs. 18% (-11%, 59%), respectively, for BNT162b2 and 24% (-41%, 72%) vs. 9% (-15%, 42%), respectively, for ChAdOx1. Conclusions BNT162b2 and ChAdOx1 reduce transmission of the Delta variant from breakthrough infections in the household setting, although their protection against infection within this setting is low.
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Affiliation(s)
- Samuel Clifford
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Pauline Waight
- National Infection Service, UK Health Security Agency, London, NW9 5EQ, UK
| | - Jada Hackman
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Stephane Hué
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Charlotte M. Gower
- National Infection Service, UK Health Security Agency, London, NW9 5EQ, UK
| | - Freja CM Kirsebom
- National Infection Service, UK Health Security Agency, London, NW9 5EQ, UK
| | - Catriona Skarnes
- National Infection Service, UK Health Security Agency, London, NW9 5EQ, UK
| | - Louise Letley
- National Infection Service, UK Health Security Agency, London, NW9 5EQ, UK
| | - Jamie Lopez Bernal
- National Infection Service, UK Health Security Agency, London, NW9 5EQ, UK
| | - Nick Andrews
- National Infection Service, UK Health Security Agency, London, NW9 5EQ, UK
| | - Stefan Flasche
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Elizabeth Miller
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
- National Infection Service, UK Health Security Agency, London, NW9 5EQ, UK
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5
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Graham S, Tessier E, Stowe J, Bernal JL, Parker EPK, Nitsch D, Miller E, Andrews N, Walker JL, McDonald HI. Bias assessment of a test-negative design study of COVID-19 vaccine effectiveness used in national policymaking. Nat Commun 2023; 14:3984. [PMID: 37414791 PMCID: PMC10325974 DOI: 10.1038/s41467-023-39674-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 06/21/2023] [Indexed: 07/08/2023] Open
Abstract
National test-negative-case-control (TNCC) studies are used to monitor COVID-19 vaccine effectiveness in the UK. A questionnaire was sent to participants from the first published TNCC COVID-19 vaccine effectiveness study conducted by the UK Health Security Agency, to assess for potential biases and changes in behaviour related to vaccination. The original study included symptomatic adults aged ≥70 years testing for COVID-19 between 08/12/2020 and 21/02/2021. A questionnaire was sent to cases and controls tested from 1-21 February 2021. In this study, 8648 individuals responded to the questionnaire (36.5% response). Using information from the questionnaire to produce a combined estimate that accounted for all potential biases decreased the original vaccine effectiveness estimate after two doses of BNT162b2 from 88% (95% CI: 79-94%) to 85% (95% CI: 68-94%). Self-reported behaviour demonstrated minimal evidence of riskier behaviour after vaccination. These findings offer reassurance to policy makers and clinicians making decisions based on COVID-19 vaccine effectiveness TNCC studies.
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Affiliation(s)
- Sophie Graham
- London School of Hygiene and Tropical Medicine, London, UK.
- UK Health Security Agency, London, UK.
- National Institute for Health and Care Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London, UK.
| | | | | | | | | | - Dorothea Nitsch
- London School of Hygiene and Tropical Medicine, London, UK
- UK Renal Registry, Bristol, UK
- Renal Unit, Royal Free London NHS Foundation Trust, Hertfordshire, UK
| | - Elizabeth Miller
- London School of Hygiene and Tropical Medicine, London, UK
- National Institute for Health and Care Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London, UK
| | - Nick Andrews
- UK Health Security Agency, London, UK
- National Institute for Health and Care Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London, UK
| | - Jemma L Walker
- London School of Hygiene and Tropical Medicine, London, UK
- UK Health Security Agency, London, UK
- National Institute for Health and Care Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London, UK
| | - Helen I McDonald
- London School of Hygiene and Tropical Medicine, London, UK
- National Institute for Health and Care Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London, UK
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6
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Zhu Y, Xia Y, Pickering J, Bowen AC, Short KR. The role of children in transmission of SARS-CoV-2 variants of concern within households: an updated systematic review and meta-analysis, as at 30 June 2022. Euro Surveill 2023; 28:2200624. [PMID: 37140450 PMCID: PMC10161681 DOI: 10.2807/1560-7917.es.2023.28.18.2200624] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 03/17/2023] [Indexed: 05/05/2023] Open
Abstract
BackgroundMeta-analyses and single-site studies have established that children are less infectious than adults within a household when positive for ancestral SARS-CoV-2. In addition, children appear less susceptible to infection when exposed to ancestral SARS-CoV-2 within a household. The emergence of SARS-CoV-2 variants of concern (VOC) has been associated with an increased number of paediatric infections worldwide. However, the role of children in the household transmission of VOC, relative to the ancestral virus, remains unclear.AimWe aimed to evaluate children's role in household transmission of SARS-CoV-2 VOC.MethodsWe perform a meta-analysis of the role of children in household transmission of both ancestral SARS-CoV-2 and SARS-CoV-2 VOC.ResultsUnlike with the ancestral virus, children infected with VOC spread SARS-CoV-2 to an equivalent number of household contacts as infected adults and were equally as likely to acquire SARS-CoV-2 VOC from an infected family member. Interestingly, the same was observed when unvaccinated children exposed to VOC were compared with unvaccinated adults exposed to VOC.ConclusionsThese data suggest that the emergence of VOC was associated with a fundamental shift in the epidemiology of SARS-CoV-2. It is unlikely that this is solely the result of age-dependent differences in vaccination during the VOC period and may instead reflect virus evolution over the course of the pandemic.
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Affiliation(s)
- Yanshan Zhu
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
- Wesfarmer's Centre for Vaccines and Infectious Diseases, Telethon Kids Institute, University of Western Australia, Nedlands, Perth, Australia
- These authors contributed equally to this manuscript
| | - Yao Xia
- Department of Microbiology, State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
- These authors contributed equally to this manuscript
| | - Janessa Pickering
- Wesfarmer's Centre for Vaccines and Infectious Diseases, Telethon Kids Institute, University of Western Australia, Nedlands, Perth, Australia
| | - Asha C Bowen
- Wesfarmer's Centre for Vaccines and Infectious Diseases, Telethon Kids Institute, University of Western Australia, Nedlands, Perth, Australia
- Department of Infectious Diseases, Perth Children's Hospital, Nedlands, Perth, Australia
| | - Kirsty R Short
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
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Gaskell KM, El Kheir N, Mirfendesky M, Rampling T, Marks M, Houlihan CF, Lemonge N, Bristowe H, Aslam S, Kyprianou D, Nastouli E, Goldblatt D, Fielding K, Moore DAJ. Comparison of new and emerging SARS-CoV-2 variant transmissibility through active contact testing. A comparative cross-sectional household seroprevalence study. PLoS One 2023; 18:e0284372. [PMID: 37093796 PMCID: PMC10124829 DOI: 10.1371/journal.pone.0284372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 03/29/2023] [Indexed: 04/25/2023] Open
Abstract
Historically SARS-CoV-2 secondary attack rates (SAR) have been based on PCR positivity on screening symptomatic contacts; this misses transmission events and identifies only symptomatic contacts who are PCR positive at the time of sampling. We used serology to detect the relative transmissibility of Alpha Variant of Concern (VOC) to non-VOC SARS-CoV-2 to calculate household secondary attack rates. We identified index patients diagnosed with Alpha and non-VOC SARS-CoV-2 across two London Hospitals between November 2020 and January 2021 during a prolonged and well adhered national lockdown. We completed a household seroprevalence survey and found that 61.8% of non-VOC exposed household contacts were seropositive compared to 82.1% of Alpha exposed household contacts. The odds of infection doubled with exposure to an index diagnosed with Alpha. There was evidence of transmission events in almost all households. Our data strongly support that estimates of SAR should include serological data to improve accuracy and understanding.
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Affiliation(s)
- Katherine M Gaskell
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Natalie El Kheir
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Tommy Rampling
- Hospital for Tropical Diseases, University College London Hospitals Foundation NHS Trust, London, United Kingdom
| | - Michael Marks
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Catherine F Houlihan
- Department of Clinical Virology, University College London Hospitals Foundation NHS Trust, London, United Kingdom
| | - Norbert Lemonge
- Department of Population, Policy and Practice, University College London Institute of Child Health, London, United Kingdom
| | - Hannah Bristowe
- Department of Population, Policy and Practice, University College London Institute of Child Health, London, United Kingdom
| | - Suhail Aslam
- Department of Population, Policy and Practice, University College London Institute of Child Health, London, United Kingdom
| | - Demetra Kyprianou
- North Middlesex University Hospital NHS Trust, London, United Kingdom
| | - Eleni Nastouli
- Infection, Immunity & Inflammation Department, University College London; Great Ormond Street Institute of Child Health, London, United Kingdom
| | - David Goldblatt
- Infectious Disease Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Katherine Fielding
- Infectious Disease Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - David A J Moore
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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8
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Clifford S, Waight P, Hackman J, Hué S, Gower CM, Kirsebom FCM, Skarnes C, Letley L, Lopez Bernal J, Andrews N, Flasche S, Miller E. Effectiveness of BNT162b2 and ChAdOx1 against SARS-CoV-2 household transmission: a prospective cohort study in England. Wellcome Open Res 2023. [DOI: 10.12688/wellcomeopenres.17995.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
Background: The ability of SARS-CoV-2 vaccines to protect against infection and onward transmission determines whether immunisation can control global circulation. We estimated the effectiveness of Pfizer-BioNTech mRNA vaccine (BNT162b2) and Oxford AstraZeneca adenovirus vector vaccine (ChAdOx1) vaccines against acquisition and transmission of the Alpha and Delta variants in a prospective household study in England. Methods: Households were recruited based on adult purported index cases testing positive after reverse transcription-quantitative (RT-q)PCR testing of oral-nasal swabs. Purported index cases and their household contacts took oral-nasal swabs on days 1, 3 and 7 after enrolment and a subset of the PCR-positive swabs underwent genomic sequencing conducted on a subset. We used Bayesian logistic regression to infer vaccine effectiveness against acquisition and transmission, adjusted for age, vaccination history and variant. Results: Between 2 February 2021 and 10 September 2021, 213 index cases and 312 contacts were followed up. After excluding households lacking genomic proximity (N=2) or with unlikely serial intervals (N=16), 195 households with 278 contacts remained, of whom 113 (41%) became PCR positive. Delta lineages had 1.53 times the risk (95% Credible Interval: 1.04 – 2.20) of transmission than Alpha; contacts older than 18 years old were 1.48 (1.20 – 1.91) and 1.02 (0.93 – 1.16) times more likely to acquire an Alpha or Delta infection than children. Effectiveness of two doses of BNT162b2 against transmission of Delta was 36% (-1%, 66%) and 49% (18%, 73%) for ChAdOx1, similar to their effectiveness for Alpha. Protection against infection with Alpha was higher than for Delta, 69% (9%, 95%) vs. 18% (-11%, 59%), respectively, for BNT162b2 and 24% (-41%, 72%) vs. 9% (-15%, 42%), respectively, for ChAdOx1. Conclusions: BNT162b2 and ChAdOx1 reduce transmission of the Delta variant from breakthrough infections in the household setting, although their protection against infection within this setting is low.
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Vardavas CI, Nikitara K, Aslanoglou K, Kamekis A, Puttige Ramesh N, Symvoulakis E, Agaku I, Phalkey R, Leonardi-Bee J, Fernandez E, Condell O, Lamb F, Deogan C, Suk JE. Systematic review of outbreaks of COVID-19 within households in the European region when the child is the index case. BMJ Paediatr Open 2023; 7:10.1136/bmjpo-2022-001718. [PMID: 36649374 PMCID: PMC9835947 DOI: 10.1136/bmjpo-2022-001718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 12/07/2022] [Indexed: 01/13/2023] Open
Abstract
OBJECTIVES This systematic review aims to identify the secondary attack rates (SAR) to adults and other children when children are the index cases within household settings. METHODS This literature review assessed European-based studies published in Medline and Embase between January 2020 and January 2022 that assessed the secondary transmission of SARS-CoV-2 within household settings. The inclusion criteria were based on the Population, Exposure, Outcome framework for systematic reviews. Thus, the study population was restricted to humans within the household setting in Europe (population), in contact with paediatric index cases 1-17 years old (exposure) that led to the transmission of SARS-CoV-2 reported as either an SAR or the probability of onward infection (outcome). RESULTS Of 1819 studies originally identified, 19 met the inclusion criteria. Overall, the SAR ranged from 13% to 75% in 15 studies, while there was no evidence of secondary transmission from children to other household members in one study. Evidence indicated that asymptomatic SARS-CoV-2 index cases also have a lower SAR than those with symptoms and that younger children may have a lower SAR than adolescents (>12 years old) within household settings. CONCLUSIONS SARS-CoV-2 secondary transmission from paediatric index cases ranged from 0% to 75%, within household settings between January 2020 and January 2022, with differences noted by age and by symptomatic/asymptomatic status of the index case. Given the anticipated endemic circulation of SARS-CoV-2, continued monitoring and assessment of household transmission is necessary.
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Affiliation(s)
- Constantine I Vardavas
- School of Medicine, University of Crete School of Medicine, Heraklion, Greece.,Department of Oral Health Policy and Epidemiology, Harvard University, Cambridge, Massachusetts, USA
| | - Katerina Nikitara
- School of Medicine, University of Crete School of Medicine, Heraklion, Greece
| | - Katerina Aslanoglou
- School of Medicine, University of Crete School of Medicine, Heraklion, Greece
| | - Apostolos Kamekis
- School of Medicine, University of Crete School of Medicine, Heraklion, Greece
| | - Nithya Puttige Ramesh
- Department of Oral Health Policy and Epidemiology, Harvard University, Cambridge, Massachusetts, USA
| | | | - Israel Agaku
- Department of Oral Health Policy and Epidemiology, Harvard University, Cambridge, Massachusetts, USA
| | - Revati Phalkey
- Centre for Evidence Based Healthcare, University of Nottingham, Nottingham, UK
| | - Jo Leonardi-Bee
- Centre for Evidence Based Healthcare, University of Nottingham, Nottingham, UK
| | - Esteve Fernandez
- Tobacco Control Unit, Catalan Institute of Oncology Institut Català d'Oncologia (ICO), L'Hospitalet de Llobregat, Barcelona, Spain.,Tobacco Control Research Group, Institut d'Investigació Biomèdica de Bellvithe (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.,CIBER Respiratory Diseases (CIBERES), Madrid, Spain.,Department of Clinical Sciences, School of Medicine and Health Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Orla Condell
- European Centre for Disease Prevention and Control (ECDC), Solna, Stockholm, Sweden
| | - Favelle Lamb
- European Centre for Disease Prevention and Control (ECDC), Solna, Stockholm, Sweden
| | - Charlotte Deogan
- European Centre for Disease Prevention and Control (ECDC), Solna, Stockholm, Sweden
| | - Jonathan E Suk
- European Centre for Disease Prevention and Control (ECDC), Solna, Stockholm, Sweden
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10
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Wang C, Huang X, Lau EHY, Cowling BJ, Tsang TK. Association Between Population-Level Factors and Household Secondary Attack Rate of SARS-CoV-2: A Systematic Review and Meta-analysis. Open Forum Infect Dis 2022; 10:ofac676. [PMID: 36655186 PMCID: PMC9835764 DOI: 10.1093/ofid/ofac676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
Background Accurate estimation of household secondary attack rate (SAR) is crucial to understand the transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The impact of population-level factors, such as transmission intensity in the community, on SAR estimates is rarely explored. Methods In this study, we included articles with original data to compute the household SAR. To determine the impact of transmission intensity in the community on household SAR estimates, we explored the association between SAR estimates and the incidence rate of cases by country during the study period. Results We identified 163 studies to extract data on SARs from 326 031 cases and 2 009 859 household contacts. The correlation between the incidence rate of cases during the study period and SAR estimates was 0.37 (95% CI, 0.24-0.49). We found that doubling the incidence rate of cases during the study period was associated with a 1.2% (95% CI, 0.5%-1.8%) higher household SAR. Conclusions Our findings suggest that the incidence rate of cases during the study period is associated with higher SAR. Ignoring this factor may overestimate SARs, especially for regions with high incidences, which further impacts control policies and epidemiological characterization of emerging variants.
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Affiliation(s)
- Can Wang
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Xiaotong Huang
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Eric H Y Lau
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China,Laboratory of Data Discovery for Health Limited, Hong Kong Science and Technology Park, New Territories, Hong Kong Special Administrative Region, China
| | - Benjamin J Cowling
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China,Laboratory of Data Discovery for Health Limited, Hong Kong Science and Technology Park, New Territories, Hong Kong Special Administrative Region, China
| | - Tim K Tsang
- Correspondence: Tim K. Tsang, PhD, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 7 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China ()
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11
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Marcato AJ, Black AJ, Walker CR, Morris D, Meagher N, Price DJ, McVernon J. Learnings from the Australian first few X household transmission project for COVID-19. THE LANCET REGIONAL HEALTH. WESTERN PACIFIC 2022; 28:100573. [PMID: 36089928 PMCID: PMC9444248 DOI: 10.1016/j.lanwpc.2022.100573] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Background First Few "X" (FFX) studies provide a platform to collect the required epidemiological, clinical and virological data to help address emerging information needs about the COVID-19 pandemic. Methods We adapted the WHO FFX protocol for COVID-19 to understand severity and household transmission dynamics in the early stages of the pandemic in Australia. Implementation strategies were developed for participating sites; all household members were followed for 14 days from case identification. Household contacts completed symptom diaries and had multiple respiratory swabs taken irrespective of symptoms. We modelled the spread of COVID-19 within households using a susceptible-exposed-infectious-recovered-type model, and calculated the household secondary attack rate and key epidemiological parameters. Findings 96 households with 101 cases and 286 household contacts were recruited into the study between April-October 2020. Forty household contacts tested positive for SARS-CoV-2 in the study follow-up period. Our model estimated the household secondary attack rate to be 15% (95% CI 8-25%), which scaled up with increasing household size. Our findings suggest children were less infectious than their adult counterparts but were also more susceptible to infection. Interpretation Our study provides important baseline data characterising the transmission of early SARS-CoV-2 strains from children and adults in Australia, against which properties of variants of concern can be benchmarked. We encountered many challenges with respect to logistics, ethics, governance and data management. Continued efforts to invest in preparedness research will help to test, refine and further develop Australian FFX study protocols in advance of future outbreaks. Funding Australian Government Department of Health.
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Affiliation(s)
- Adrian J. Marcato
- Department of Infectious Diseases, The University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Andrew J. Black
- School of Mathematical Sciences, The University of Adelaide, Adelaide, Australia
| | - Camelia R. Walker
- School of Mathematical Sciences, The University of Adelaide, Adelaide, Australia
- School of Mathematics & Statistics, The University of Melbourne, Melbourne, Australia
| | - Dylan Morris
- School of Mathematical Sciences, The University of Adelaide, Adelaide, Australia
| | - Niamh Meagher
- Department of Infectious Diseases, The University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Centre for Epidemiology & Biostatistics, Melbourne School of Population & Global Health, The University of Melbourne
| | - David J. Price
- Department of Infectious Diseases, The University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Centre for Epidemiology & Biostatistics, Melbourne School of Population & Global Health, The University of Melbourne
| | - Jodie McVernon
- Department of Infectious Diseases, The University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Centre for Epidemiology & Biostatistics, Melbourne School of Population & Global Health, The University of Melbourne
- Murdoch Children's Research Institute, Melbourne, Australia
| | - the Australian FFX Household Transmission Project Group
- Department of Infectious Diseases, The University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- School of Mathematical Sciences, The University of Adelaide, Adelaide, Australia
- School of Mathematics & Statistics, The University of Melbourne, Melbourne, Australia
- Centre for Epidemiology & Biostatistics, Melbourne School of Population & Global Health, The University of Melbourne
- Murdoch Children's Research Institute, Melbourne, Australia
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12
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Transmission of SARS-CoV-2 by children to contacts in schools and households: a prospective cohort and environmental sampling study in London. THE LANCET. MICROBE 2022; 3:e814-e823. [PMID: 36029775 PMCID: PMC9401977 DOI: 10.1016/s2666-5247(22)00124-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/20/2022] [Accepted: 04/29/2022] [Indexed: 01/14/2023]
Abstract
BACKGROUND Assessing transmission of SARS-CoV-2 by children in schools is of crucial importance to inform public health action. We assessed frequency of acquisition of SARS-CoV-2 by contacts of pupils with COVID-19 in schools and households, and quantified SARS-CoV-2 shedding into air and onto fomites in both settings. METHODS We did a prospective cohort and environmental sampling study in London, UK in eight schools. Schools reporting new cases of SARS-CoV-2 infection to local health protection teams were invited to take part if a child index case had been attending school in the 48 h before a positive SARS-CoV-2 PCR test. At the time of the study, PCR testing was available to symptomatic individuals only. Children aged 2-14 years (extended to <18 years in November, 2020) with a new nose or throat swab SARS-CoV-2 positive PCR from an accredited laboratory were included. Incidents involving exposure to at least one index pupil with COVID-19 were identified (the prevailing variants were original, α, and δ). Weekly PCR testing for SARS-CoV-2 was done on immediate classroom contacts (the so-called bubble), non-bubble school contacts, and household contacts of index pupils. Testing was supported by genome sequencing and on-surface and air samples from school and home environments. FINDINGS Between October, 2020, and July, 2021 from the eight schools included, secondary transmission of SARS-CoV-2 was not detected in 28 bubble contacts, representing ten bubble classes (participation rate 8·8% [IQR 4·6-15·3]). Across eight non-bubble classes, 3 (2%) of 62 pupils tested positive, but these were unrelated to the original index case (participation rate 22·5% [9·7-32·3]). All three were asymptomatic and tested positive in one setting on the same day. In contrast, secondary transmission to previously negative household contacts from infected index pupils was found in six (17%) of 35 household contacts rising to 13 (28%) of 47 household contacts when considering all potential infections in household contacts. Environmental contamination with SARS-CoV-2 was rare in schools: fomite SARS-CoV-2 was identified in four (2%) of 189 samples in bubble classrooms, two (2%) of 127 samples in non-bubble classrooms, and five (4%) of 130 samples in washrooms. This contrasted with fomites in households, where SARS-CoV-2 was identified in 60 (24%) of 248 bedroom samples, 66 (27%) of 241 communal room samples, and 21 (11%) 188 bathroom samples. Air sampling identified SARS-CoV-2 RNA in just one (2%) of 68 of school air samples, compared with 21 (25%) of 85 air samples taken in homes. INTERPRETATION There was no evidence of large-scale SARS-CoV-2 transmission in schools with precautions in place. Low levels of environmental contamination in schools are consistent with low transmission frequency and suggest adequate cleaning and ventilation in schools during the period of study. The high frequency of secondary transmission in households associated with evident viral shedding throughout the home suggests a need to improve advice to households with infection in children to prevent onward community spread. The data suggest that SARS-CoV-2 transmission from children in any setting is very likely to occur when precautions are reduced. FUNDING UK Research and Innovation and UK Department of Health and Social Care, National Institute for Health and Care Research.
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13
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Chen F, Tian Y, Zhang L, Shi Y. The role of children in household transmission of COVID-19: a systematic review and meta-analysis. Int J Infect Dis 2022; 122:266-275. [PMID: 35562045 PMCID: PMC9091150 DOI: 10.1016/j.ijid.2022.05.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/03/2022] [Accepted: 05/07/2022] [Indexed: 02/08/2023] Open
Abstract
OBJECTIVES To explore household transmissibility of SARS-CoV-2 in children in new-variants dominating periods. METHODS Through retrieval in PubMed and Embase, studies were included in two parts: meta-analysis of the household secondary attack rate (SAR) and case analysis of household pediatric infections. RESULTS A total of 95 articles were included: 48 for meta-analysis and 47 for case analysis. Pediatric COVID-19 only comprised a minority of the household transmission. The total pooled household SAR of child index cases and contacts were 0.20 (95% confidence interval [CI]: 0.15-0.26) and 0.24 (95% CI: 0.18-0.30). Lower household transmissibility was reported in both child index cases and contacts than in adults (relative risk [RR] = 0.64, 95% CI: 0.50-0.81; RR = 0.74, 95% CI: 0.64-0.85). Younger children were as susceptible as the older children (RR = 0.89, 95% CI: 0.72-1.10). Through subgroup analyses of different variants and periods, increased household SAR was observed in children (Wild: 0.20; Alpha: 0.42; Delta: 0.35; Omicron: 0.56), and no significant difference was found in household SAR between children and adults when new variants dominated. CONCLUSION Although children were found not to be dominant in the household transmission, their transmissibility of SARS-CoV-2 appeared to be on the rise as new variants emerged.
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Affiliation(s)
| | | | | | - Yuan Shi
- Corresponding author: Yuan Shi, Children's Hospital of Chongqing Medical University, Chongqing 400014, China, Mob: 00862363635678
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14
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Ijaz S, Dicks S, Jegatheesan K, Parker E, Katsanovskaja K, Vink E, McClure MO, Shute J, Hope J, Cook N, Cherepanov P, Turtle L, Paxton WA, Pollakis G, Ho A, Openshaw PJM, Baillie JK, Semple MG, Tedder RS. Mapping of SARS-CoV-2 IgM and IgG in gingival crevicular fluid: Antibody dynamics and linkage to severity of COVID-19 in hospital inpatients. J Infect 2022; 85:152-160. [PMID: 35667482 PMCID: PMC9163047 DOI: 10.1016/j.jinf.2022.05.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 05/19/2022] [Accepted: 05/29/2022] [Indexed: 02/06/2023]
Affiliation(s)
- Samreen Ijaz
- Blood Borne Virus Unit, Reference Department, UK Health Security Agency, 61 Colindale Avenue, London NW9 5EQ, UK.
| | - Steve Dicks
- Blood Borne Virus Unit, Reference Department, UK Health Security Agency, 61 Colindale Avenue, London NW9 5EQ, UK; NHS Blood and Transplant, London, UK
| | - Keerthana Jegatheesan
- Blood Borne Virus Unit, Reference Department, UK Health Security Agency, 61 Colindale Avenue, London NW9 5EQ, UK; NHS Blood and Transplant, London, UK
| | - Eleanor Parker
- Department of Infectious Disease, Imperial College London, London, UK
| | | | - Elen Vink
- Medical Research Council, University of Glasgow Centre for Virus Research, Glasgow, UK
| | - Myra O McClure
- Department of Infectious Disease, Imperial College London, London, UK
| | - J Shute
- Blood Borne Virus Unit, Reference Department, UK Health Security Agency, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Joshua Hope
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
| | - Nicola Cook
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
| | - Peter Cherepanov
- Department of Infectious Disease, Imperial College London, London, UK; Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
| | - Lance Turtle
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK; Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
| | - William A Paxton
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK; NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Georgios Pollakis
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK; NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Antonia Ho
- Medical Research Council, University of Glasgow Centre for Virus Research, Glasgow, UK
| | | | | | - Malcolm G Semple
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK; Department of Respiratory Medicine, Alder Hey Children's Hospital, Liverpool, UK
| | - Richard S Tedder
- Department of Infectious Disease, Imperial College London, London, UK
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15
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Nash D, Qasmieh S, Robertson M, Rane M, Zimba R, Kulkarni SG, Berry A, You W, Mirzayi C, Westmoreland D, Parcesepe A, Waldron L, Kochhar S, Maroko AR, Grov C. Household factors and the risk of severe COVID-like illness early in the U.S. pandemic. PLoS One 2022; 17:e0271786. [PMID: 35862418 PMCID: PMC9302833 DOI: 10.1371/journal.pone.0271786] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 07/07/2022] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE To investigate the role of children in the home and household crowding as risk factors for severe COVID-19 disease. METHODS We used interview data from 6,831 U.S. adults screened for the Communities, Households and SARS/CoV-2 Epidemiology (CHASING) COVID Cohort Study in April 2020. RESULTS In logistic regression models, the adjusted odds ratio [aOR] of hospitalization due to COVID-19 for having (versus not having) children in the home was 10.5 (95% CI:5.7-19.1) among study participants living in multi-unit dwellings and 2.2 (95% CI:1.2-6.5) among those living in single unit dwellings. Among participants living in multi-unit dwellings, the aOR for COVID-19 hospitalization among participants with more than 4 persons in their household (versus 1 person) was 2.5 (95% CI:1.0-6.1), and 0.8 (95% CI:0.15-4.1) among those living in single unit dwellings. CONCLUSION Early in the US SARS-CoV-2 pandemic, certain household exposures likely increased the risk of both SARS-CoV-2 acquisition and the risk of severe COVID-19 disease.
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Affiliation(s)
- Denis Nash
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
- Department of Epidemiology and Biostatistics, Graduate School of Public Health and Health Policy, City University of New York (CUNY), New York City, New York, United States of America
| | - Saba Qasmieh
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
- Department of Epidemiology and Biostatistics, Graduate School of Public Health and Health Policy, City University of New York (CUNY), New York City, New York, United States of America
| | - McKaylee Robertson
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
- Department of Epidemiology and Biostatistics, Graduate School of Public Health and Health Policy, City University of New York (CUNY), New York City, New York, United States of America
| | - Madhura Rane
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
| | - Rebecca Zimba
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
- Department of Epidemiology and Biostatistics, Graduate School of Public Health and Health Policy, City University of New York (CUNY), New York City, New York, United States of America
| | - Sarah G. Kulkarni
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
| | - Amanda Berry
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
| | - William You
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
| | - Chloe Mirzayi
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
- Department of Epidemiology and Biostatistics, Graduate School of Public Health and Health Policy, City University of New York (CUNY), New York City, New York, United States of America
| | - Drew Westmoreland
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
| | - Angela Parcesepe
- Department of Maternal and Child Health, Gillings School of Public Health, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Levi Waldron
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
- Department of Environmental, Occupational, and Geospatial Health Sciences, Graduate School of Public Health and Health Policy, City University of New York (CUNY), New York City, New York, United States of America
| | - Shivani Kochhar
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
| | - Andrew R. Maroko
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
- Department of Environmental, Occupational, and Geospatial Health Sciences, Graduate School of Public Health and Health Policy, City University of New York (CUNY), New York City, New York, United States of America
| | - Christian Grov
- Institute for Implementation Science in Population Health (ISPH), City University of New York (CUNY), New York City, New York, United States of America
- Department of Community Health and Social Sciences, Graduate School of Public Health and Health Policy, City University of New York (CUNY), New York City, New York, United States of America
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16
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COVID-19 in children: epidemic issues and candidate vaccines. Chin Med J (Engl) 2022; 135:1314-1324. [PMID: 35830254 PMCID: PMC9433085 DOI: 10.1097/cm9.0000000000002169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
A large-scale vaccination of coronavirus disease-19 (COVID-19) in adults has been conducted for nearly a year, and there is a growing recognition that immunization for children is also essential. It has been months since emergency use of pediatric COVID-19 vaccine was approved, we reviewed the prevalence and transmission of COVID-19 in children. The prevalence of COVID-19 in children is reduced due to vaccination even in a Delta prevalent period, so an increase in the vaccination rate is needed in children. Although the precise role of children in the transmission requires more research to uncover, they likely played a significant role, according to the available literature. We also described four candidate COVID-19 vaccines for children on their safety and immunogenicity and the impact of severe acute respiratory syndrome coronavirus 2 variants on childhood vaccination. Safety issues on pediatric vaccines post-approval, like adverse events following immunization and adverse events of special interest require studies on long-term and effective regulatory mechanisms.
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17
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Madewell ZJ, Yang Y, Longini IM, Halloran ME, Dean NE. Household Secondary Attack Rates of SARS-CoV-2 by Variant and Vaccination Status: An Updated Systematic Review and Meta-analysis. JAMA Netw Open 2022; 5:e229317. [PMID: 35482308 PMCID: PMC9051991 DOI: 10.1001/jamanetworkopen.2022.9317] [Citation(s) in RCA: 112] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
IMPORTANCE An overall household secondary attack rate (SAR) of 18.9% (95% CI, 16.2%-22.0%) through June 17, 2021 was previously reported for SARS-CoV-2. Emerging variants of concern and increased vaccination have affected transmission rates. OBJECTIVE To evaluate how reported household SARs changed over time and whether SARs varied by viral variant and index case and contact vaccination status. DATA SOURCES PubMed and medRxiv from June 18, 2021, through March 8, 2022, and reference lists of eligible articles. Preprints were included. STUDY SELECTION Articles with original data reporting the number of infected and total number of household contacts. Search terms included SARS-CoV-2, COVID-19, variant, vaccination, secondary attack rate, secondary infection rate, household, index case, family contacts, close contacts, and family transmission. DATA EXTRACTION AND SYNTHESIS The Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guideline was followed. Meta-analyses used generalized linear mixed models to obtain SAR estimates and 95% CIs. MAIN OUTCOMES AND MEASURES SAR stratified by covariates according to variant, index case and contact vaccination status, and index case identification period. SARs were used to estimate vaccine effectiveness on the basis of the transmission probability for susceptibility to infection (VES,p), infectiousness given infection (VEI,p), and total vaccine effectiveness (VET,p). RESULTS Household SARs were higher for 33 studies with midpoints in 2021 to 2022 (37.3%; 95% CI, 32.7% to 42.1%) compared with 63 studies with midpoints through April 2020 (15.5%; 95% CI, 13.2% to 18.2%). Household SARs were 42.7% (95% CI, 35.4% to 50.4%) for Omicron (7 studies), 36.4% (95% CI, 33.4% to 39.5%) for Alpha (11 studies), 29.7% (95% CI, 23.0% to 37.3%) for Delta (16 studies), and 22.5% (95% CI, 18.6% to 26.8%) for Beta (3 studies). For full vaccination, VES,p was 78.6% (95% CI, 76.0% to 80.9%) for Alpha, 56.4% (95% CI, 54.6% to 58.1%) for Delta, and 18.1% (95% CI, -18.3% to 43.3%) for Omicron; VEI,p was 75.3% (95% CI, 69.9% to 79.8%) for Alpha, 21.9% (95% CI, 11.0% to 31.5%) for Delta, and 18.2% (95% CI, 0.6% to 32.6%) for Omicron; and VET,p was 94.7% (95% CI, 93.3% to 95.8%) for Alpha, 64.4% (95% CI, 58.0% to 69.8%) for Delta, and 35.8% (95% CI, 13.0% to 52.6%) for Omicron. CONCLUSIONS AND RELEVANCE These results suggest that emerging SARS-CoV-2 variants of concern have increased transmissibility. Full vaccination was associated with reductions in susceptibility and infectiousness, but more so for Alpha than Delta and Omicron. The changes in estimated vaccine effectiveness underscore the challenges of developing effective vaccines concomitant with viral evolution.
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Affiliation(s)
| | - Yang Yang
- Department of Biostatistics, University of Florida, Gainesville
| | - Ira M. Longini
- Department of Biostatistics, University of Florida, Gainesville
| | - M. Elizabeth Halloran
- Fred Hutchinson Cancer Research Center, Seattle, Washington
- Department of Biostatistics, University of Washington, Seattle
| | - Natalie E. Dean
- Department of Biostatistics and Bioinformatics, Emory University, Atlanta, Georgia
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18
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Lopez Bernal J, Panagiotopoulos N, Byers C, Garcia Vilaplana T, Boddington N, Zhang XS, Charlett A, Elgohari S, Coughlan L, Whillock R, Logan S, Bolt H, Sinnathamby M, Letley L, MacDonald P, Vivancos R, Edeghere O, Anderson C, Paranthaman K, Cottrell S, McMenamin J, Zambon M, Dabrera G, Ramsay M, Saliba V. Transmission dynamics of COVID-19 in household and community settings in the United Kingdom, January to March 2020. Euro Surveill 2022; 27. [PMID: 35426357 DOI: 10.1101/2020.08.19.20177188] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023] Open
Abstract
BackgroundHouseholds appear to be the highest risk setting for COVID-19 transmission. Large household transmission studies in the early stages of the pandemic in Asia reported secondary attack rates ranging from 5 to 30%.AimWe aimed to investigate the transmission dynamics of COVID-19 in household and community settings in the UK.MethodsA prospective case-ascertained study design based on the World Health Organization FFX protocol was undertaken in the UK following the detection of the first case in late January 2020. Household contacts of cases were followed using enhanced surveillance forms to establish whether they developed symptoms of COVID-19, became confirmed cases and their outcomes. We estimated household secondary attack rates (SAR), serial intervals and individual and household basic reproduction numbers. The incubation period was estimated using known point source exposures that resulted in secondary cases.ResultsWe included 233 households with two or more people with 472 contacts. The overall household SAR was 37% (95% CI: 31-43%) with a mean serial interval of 4.67 days, an R0 of 1.85 and a household reproduction number of 2.33. SAR were lower in larger households and highest when the primary case was younger than 18 years. We estimated a mean incubation period of around 4.5 days.ConclusionsRates of COVID-19 household transmission were high in the UK for ages above and under 18 years, emphasising the need for preventative measures in this setting. This study highlights the importance of the FFX protocol in providing early insights on transmission dynamics.
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Affiliation(s)
- Jamie Lopez Bernal
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | | | - Chloe Byers
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | | | - Nicki Boddington
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Xu-Sheng Zhang
- Statistics, Modelling and Economics Department, Public Health England, London, United Kingdom
| | - Andre Charlett
- Statistics, Modelling and Economics Department, Public Health England, London, United Kingdom
| | - Suzanne Elgohari
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Laura Coughlan
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Rosie Whillock
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Sophie Logan
- Field Services Division, Public Health England, London, United Kingdom
| | - Hikaru Bolt
- Field Services Division, Public Health England, London, United Kingdom
| | - Mary Sinnathamby
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Louise Letley
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Pauline MacDonald
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Roberto Vivancos
- Field Services Division, Public Health England, London, United Kingdom
| | - Obaghe Edeghere
- Field Services Division, Public Health England, London, United Kingdom
| | | | | | | | | | - Maria Zambon
- TARGET Department, Public Health England, London, United Kingdom
| | - Gavin Dabrera
- TARGET Department, Public Health England, London, United Kingdom
| | - Mary Ramsay
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Vanessa Saliba
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
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19
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Bhatt M, Plint AC, Tang K, Malley R, Huy AP, McGahern C, Dawson J, Pelchat M, Dawson L, Varshney T, Arnold C, Galipeau Y, Austin M, Thampi N, Alnaji F, Langlois MA, Zemek RL. Household transmission of SARS-CoV-2 from unvaccinated asymptomatic and symptomatic household members with confirmed SARS-CoV-2 infection: an antibody-surveillance study. CMAJ Open 2022; 10:E357-E366. [PMID: 35414597 PMCID: PMC9007444 DOI: 10.9778/cmajo.20220026] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Household transmission contributes to SARS-CoV-2 spread, but the role of children in transmission is unclear. We conducted a study that included symptomatic and asymptomatic children and adults exposed to SARS-CoV-2 in their households with the objective of determining how SARS-CoV-2 is transmitted within households. METHODS In this case-ascertained antibody-surveillance study, we enrolled households in Ottawa, Ontario, in which at least 1 household member had tested positive for SARS-CoV-2 on reverse transcription polymerase chain reaction testing. The enrolment period was September 2020 to March 2021. Potentially eligible participants were identified if they had tested positive for SARS-CoV-2 at an academic emergency department or affiliated testing centre; people who learned about the study through the media could also self-identify for participation. At least 2 participants were required for a household to be eligible for study participation, and at least 1 enrolled participant per household had to be a child (age < 18 yr). Enzyme-linked immunosorbent assays were used to evaluate SARS-CoV-2-specific IgA, IgM and IgG against the spike-trimer and nucleocapsid protein. The primary outcome was household secondary attack rate, defined as the proportion of household contacts positive for SARS-CoV-2 antibody among the total number of household contacts participating in the study. We performed descriptive statistics at both the individual and household levels. To estimate and compare outcomes between patient subgroups, and to examine predictors of household transmission, we fitted a series of multivariable logistic regression with robust standard errors to account for clustering of individuals within households. RESULTS We enrolled 695 participants from 180 households: 180 index participants (74 children, 106 adults) and 515 of their household contacts (266 children, 249 adults). A total of 487 household contacts (94.6%) (246 children, 241 adults) had SARS-CoV-2 antibody testing, of whom 239 had a positive result (secondary attack rate 49.1%, 95% confidence interval [CI] 42.9%-55.3%). Eighty-eight (36.8%, 95% CI 29.3%-43.2%) of the 239 were asymptomatic; asymptomatic rates were similar for children (51/130 [39.2%, 95% CI 30.7%-48.5%]) and adults (37/115 [32.2%, 95% CI 24.2%-41.4%]) (odds ratio [OR] 1.3, 95% CI 0.8-2.1). Adults were more likely than children to transmit SARS-CoV-2 (OR 2.2, 95% CI 1.3-3.6). The odds of transmission from asymptomatic (OR 0.6, 95% CI 0.2-1.4) versus symptomatic (OR 0.9, 95% CI 0.6-1.4) index participants to household contacts was uncertain. Predictors of household transmission included household density (number of people per bedroom), relationship to index participant and number of cases in the household. INTERPRETATION The rate of SARS-CoV-2 transmission within households was nearly 50% during the study period, and children were an important source of spread. The findings suggest that children are an important driver of the COVID-19 pandemic; this should inform public health policy.
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Affiliation(s)
- Maala Bhatt
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont.
| | - Amy C Plint
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Ken Tang
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Richard Malley
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Anne Pham Huy
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Candice McGahern
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Jennifer Dawson
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Martin Pelchat
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Lauren Dawson
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Terry Varshney
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Corey Arnold
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Yannick Galipeau
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Michael Austin
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Nisha Thampi
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Fuad Alnaji
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Marc-André Langlois
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
| | - Roger L Zemek
- Department of Pediatrics (Bhatt, Plint, Pham Huy, Varshney, Thampi, Alnaji, Zemek), Children's Hospital of Eastern Ontario, University of Ottawa; Department of Emergency Medicine (Plint, Alnaji, Zemek), University of Ottawa; Children's Hospital of Eastern Ontario Research Institute (Tang, McGahern, J. Dawson, L. Dawson, Austin), Ottawa, Ont.; Division of Infectious Diseases (Malley), Boston Children's Hospital and Harvard Medical School, Boston, Mass.; Department of Biochemistry, Microbiology and Immunology (Pelchat, Arnold, Galipeau, Langlois), Faculty of Medicine, University of Ottawa; University of Ottawa Centre for Infection, Immunity and Inflammation (Pelchat, Langlois); Ottawa Hospital Research Institute (Austin), Ottawa, Ont
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20
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Lopez Bernal J, Panagiotopoulos N, Byers C, Garcia Vilaplana T, Boddington N, Zhang XS, Charlett A, Elgohari S, Coughlan L, Whillock R, Logan S, Bolt H, Sinnathamby M, Letley L, MacDonald P, Vivancos R, Edeghere O, Anderson C, Paranthaman K, Cottrell S, McMenamin J, Zambon M, Dabrera G, Ramsay M, Saliba V. Transmission dynamics of COVID-19 in household and community settings in the United Kingdom, January to March 2020. Euro Surveill 2022; 27:2001551. [PMID: 35426357 PMCID: PMC9012093 DOI: 10.2807/1560-7917.es.2022.27.15.2001551] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 02/20/2022] [Indexed: 12/23/2022] Open
Abstract
BackgroundHouseholds appear to be the highest risk setting for COVID-19 transmission. Large household transmission studies in the early stages of the pandemic in Asia reported secondary attack rates ranging from 5 to 30%.AimWe aimed to investigate the transmission dynamics of COVID-19 in household and community settings in the UK.MethodsA prospective case-ascertained study design based on the World Health Organization FFX protocol was undertaken in the UK following the detection of the first case in late January 2020. Household contacts of cases were followed using enhanced surveillance forms to establish whether they developed symptoms of COVID-19, became confirmed cases and their outcomes. We estimated household secondary attack rates (SAR), serial intervals and individual and household basic reproduction numbers. The incubation period was estimated using known point source exposures that resulted in secondary cases.ResultsWe included 233 households with two or more people with 472 contacts. The overall household SAR was 37% (95% CI: 31-43%) with a mean serial interval of 4.67 days, an R0 of 1.85 and a household reproduction number of 2.33. SAR were lower in larger households and highest when the primary case was younger than 18 years. We estimated a mean incubation period of around 4.5 days.ConclusionsRates of COVID-19 household transmission were high in the UK for ages above and under 18 years, emphasising the need for preventative measures in this setting. This study highlights the importance of the FFX protocol in providing early insights on transmission dynamics.
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Affiliation(s)
- Jamie Lopez Bernal
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | | | - Chloe Byers
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | | | - Nicki Boddington
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Xu-Sheng Zhang
- Statistics, Modelling and Economics Department, Public Health England, London, United Kingdom
| | - Andre Charlett
- Statistics, Modelling and Economics Department, Public Health England, London, United Kingdom
| | - Suzanne Elgohari
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Laura Coughlan
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Rosie Whillock
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Sophie Logan
- Field Services Division, Public Health England, London, United Kingdom
| | - Hikaru Bolt
- Field Services Division, Public Health England, London, United Kingdom
| | - Mary Sinnathamby
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Louise Letley
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Pauline MacDonald
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Roberto Vivancos
- Field Services Division, Public Health England, London, United Kingdom
| | - Obaghe Edeghere
- Field Services Division, Public Health England, London, United Kingdom
| | | | | | | | | | - Maria Zambon
- TARGET Department, Public Health England, London, United Kingdom
| | - Gavin Dabrera
- TARGET Department, Public Health England, London, United Kingdom
| | - Mary Ramsay
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
| | - Vanessa Saliba
- Immunisation and Countermeasures Department, Public Health England, London, United Kingdom
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21
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David J, Bragazzi NL, Scarabel F, McCarthy Z, Wu J. Non-pharmaceutical intervention levels to reduce the COVID-19 attack ratio among children. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211863. [PMID: 35308622 PMCID: PMC8924746 DOI: 10.1098/rsos.211863] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 02/25/2022] [Indexed: 05/03/2023]
Abstract
The attack ratio in a subpopulation is defined as the total number of infections over the total number of individuals in this subpopulation. Using a methodology based on an age-stratified transmission dynamics model, we estimated the attack ratio of COVID-19 among children (individuals 0-11 years) when a large proportion of individuals eligible for vaccination (age 12 and above) are vaccinated to contain the epidemic among this subpopulation, or the effective herd immunity (with additional physical distancing measures). We describe the relationship between the attack ratio among children, the time to remove infected individuals from the transmission chain and the children-to-children daily contact rate while considering the increased transmissibility of virus variants (using the Delta variant as an example). We illustrate the generality and applicability of the methodology established by performing an analysis of the attack ratio of COVID-19 among children in the population of Canada and in its province of Ontario. The clinical attack ratio, defined as the number of symptomatic infections over the total population, can be informed from the attack ratio and both can be reduced substantially via a combination of reduced social mixing and rapid testing and isolation of the children.
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Affiliation(s)
- Jummy David
- Fields-CQAM Laboratory of Mathematics for Public Health (MfPH), York University, Toronto, Ontario, Canada
- Laboratory for Industrial and Applied Mathematics, York University, Toronto, Ontario, Canada
| | - Nicola Luigi Bragazzi
- Fields-CQAM Laboratory of Mathematics for Public Health (MfPH), York University, Toronto, Ontario, Canada
- Laboratory for Industrial and Applied Mathematics, York University, Toronto, Ontario, Canada
| | - Francesca Scarabel
- Department of Mathematics, The University of Manchester, Manchester, UK
- Joint UNIversities Pandemic and Epidemiological Research (JUNIPER), UK
- CDLab - Computational Dynamics Laboratory, Department of Mathematics, Computer Science and Physics, University of Udine, Italy
| | - Zachary McCarthy
- Fields-CQAM Laboratory of Mathematics for Public Health (MfPH), York University, Toronto, Ontario, Canada
- Laboratory for Industrial and Applied Mathematics, York University, Toronto, Ontario, Canada
| | - Jianhong Wu
- Fields-CQAM Laboratory of Mathematics for Public Health (MfPH), York University, Toronto, Ontario, Canada
- Laboratory for Industrial and Applied Mathematics, York University, Toronto, Ontario, Canada
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22
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Hart WS, Abbott S, Endo A, Hellewell J, Miller E, Andrews N, Maini PK, Funk S, Thompson RN. Inference of the SARS-CoV-2 generation time using UK household data. eLife 2022; 11:70767. [PMID: 35138250 PMCID: PMC8967386 DOI: 10.7554/elife.70767] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 02/07/2022] [Indexed: 11/17/2022] Open
Abstract
The distribution of the generation time (the interval between individuals becoming infected and transmitting the virus) characterises changes in the transmission risk during SARS-CoV-2 infections. Inferring the generation time distribution is essential to plan and assess public health measures. We previously developed a mechanistic approach for estimating the generation time, which provided an improved fit to data from the early months of the COVID-19 pandemic (December 2019-March 2020) compared to existing models (Hart et al., 2021). However, few estimates of the generation time exist based on data from later in the pandemic. Here, using data from a household study conducted from March to November 2020 in the UK, we provide updated estimates of the generation time. We considered both a commonly used approach in which the transmission risk is assumed to be independent of when symptoms develop, and our mechanistic model in which transmission and symptoms are linked explicitly. Assuming independent transmission and symptoms, we estimated a mean generation time (4.2 days, 95% credible interval 3.3–5.3 days) similar to previous estimates from other countries, but with a higher standard deviation (4.9 days, 3.0–8.3 days). Using our mechanistic approach, we estimated a longer mean generation time (5.9 days, 5.2–7.0 days) and a similar standard deviation (4.8 days, 4.0–6.3 days). As well as estimating the generation time using data from the entire study period, we also considered whether the generation time varied temporally. Both models suggest a shorter mean generation time in September-November 2020 compared to earlier months. Since the SARS-CoV-2 generation time appears to be changing, further data collection and analysis is necessary to continue to monitor ongoing transmission and inform future public health policy decisions.
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Affiliation(s)
| | - Sam Abbott
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Akira Endo
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Joel Hellewell
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Elizabeth Miller
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Nick Andrews
- Data and Analytical Sciences, UK Health Security Agency, Public Health England, London, United Kingdom
| | - Philip K Maini
- Mathematical Institute, University of Oxford, Oxford, United Kingdom
| | - Sebastian Funk
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Robin N Thompson
- Mathematics Institute, University of Warwick, Coventry, United Kingdom
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23
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Madewell ZJ, Yang Y, Longini IM, Halloran ME, Dean NE. Household secondary attack rates of SARS-CoV-2 by variant and vaccination status: an updated systematic review and meta-analysis. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2022:2022.01.09.22268984. [PMID: 35043125 PMCID: PMC8764734 DOI: 10.1101/2022.01.09.22268984] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We previously reported a household secondary attack rate (SAR) for SARS-CoV-2 of 18.9% through June 17, 2021. To examine how emerging variants and increased vaccination have affected transmission rates, we searched PubMed from June 18, 2021, through January 7, 2022. Meta-analyses used generalized linear mixed models to obtain SAR estimates and 95%CI, disaggregated by several covariates. SARs were used to estimate vaccine effectiveness based on the transmission probability for susceptibility ( VE S,p ), infectiousness ( VE I,p ), and total vaccine effectiveness ( VE T,p ). Household SAR for 27 studies with midpoints in 2021 was 35.8% (95%CI, 30.6%-41.3%), compared to 15.7% (95%CI, 13.3%-18.4%) for 62 studies with midpoints through April 2020. Household SARs were 38.0% (95%CI, 36.0%-40.0%), 30.8% (95%CI, 23.5%-39.3%), and 22.5% (95%CI, 18.6%-26.8%) for Alpha, Delta, and Beta, respectively. VE I,p , VE S,p , and VE T,p were 56.6% (95%CI, 28.7%-73.6%), 70.3% (95%CI, 59.3%-78.4%), and 86.8% (95%CI, 76.7%-92.5%) for full vaccination, and 27.5% (95%CI, -6.4%-50.7%), 43.9% (95%CI, 21.8%-59.7%), and 59.9% (95%CI, 34.4%-75.5%) for partial vaccination, respectively. Household contacts exposed to Alpha or Delta are at increased risk of infection compared to the original wild-type strain. Vaccination reduced susceptibility to infection and transmission to others. SUMMARY Household secondary attack rates (SARs) were higher for Alpha and Delta variants than previous estimates. SARs were higher to unvaccinated contacts than to partially or fully vaccinated contacts and were higher from unvaccinated index cases than from fully vaccinated index cases.
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Affiliation(s)
| | - Yang Yang
- Department of Biostatistics, University of Florida, Gainesville, FL
| | - Ira M. Longini
- Department of Biostatistics, University of Florida, Gainesville, FL
| | - M. Elizabeth Halloran
- Fred Hutchinson Cancer Research Center, Seattle, WA
- Department of Biostatistics, University of Washington, Seattle, WA
| | - Natalie E. Dean
- Department of Biostatistics, University of Florida, Gainesville, FL
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24
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Allen H, Vusirikala A, Flannagan J, Twohig KA, Zaidi A, Chudasama D, Lamagni T, Groves N, Turner C, Rawlinson C, Lopez-Bernal J, Harris R, Charlett A, Dabrera G, Kall M. Household transmission of COVID-19 cases associated with SARS-CoV-2 delta variant (B.1.617.2): national case-control study. THE LANCET REGIONAL HEALTH. EUROPE 2022; 12:100252. [PMID: 34729548 PMCID: PMC8552812 DOI: 10.1016/j.lanepe.2021.100252] [Citation(s) in RCA: 103] [Impact Index Per Article: 51.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The SARS-CoV-2 Delta variant (B.1.617.2), first detected in India, has rapidly become the dominant variant in England. Early reports suggest this variant has an increased growth rate suggesting increased transmissibility. This study indirectly assessed differences in transmissibility between the emergent Delta variant compared to the previously dominant Alpha variant (B.1.1.7). METHODS A matched case-control study was conducted to estimate the odds of household transmission (≥ 2 cases within 14 days) for Delta variant index cases compared with Alpha cases. Cases were derived from national surveillance data (March to June 2021). One-to-two matching was undertaken on geographical location of residence, time period of testing and property type, and a multivariable conditional logistic regression model was used for analysis. FINDINGS In total 5,976 genomically sequenced index cases in household clusters were matched to 11,952 sporadic index cases (single case within a household). 43.3% (n=2,586) of cases in household clusters were confirmed Delta variant compared to 40.4% (n= 4,824) of sporadic cases. The odds ratio of household transmission was 1.70 among Delta variant cases (95% CI 1.48-1.95, p <0.001) compared to Alpha cases after adjusting for age, sex, ethnicity, index of multiple deprivation (IMD), number of household contacts and vaccination status of index case. INTERPRETATION We found evidence of increased household transmission of SARS-CoV-2 Delta variant, potentially explaining its success at displacing Alpha variant as the dominant strain in England. With the Delta variant now having been detected in many countries worldwide, the understanding of the transmissibility of this variant is important for informing infection prevention and control policies internationally.
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Affiliation(s)
| | | | - Joe Flannagan
- National Infection Service, Public Health England, Colindale, London, NW9 5EQ, UK
| | - Katherine A. Twohig
- National Infection Service, Public Health England, Colindale, London, NW9 5EQ, UK
| | - Asad Zaidi
- National Infection Service, Public Health England, Colindale, London, NW9 5EQ, UK
| | - Dimple Chudasama
- National Infection Service, Public Health England, Colindale, London, NW9 5EQ, UK
| | - Theresa Lamagni
- National Infection Service, Public Health England, Colindale, London, NW9 5EQ, UK
| | - Natalie Groves
- National Infection Service, Public Health England, Colindale, London, NW9 5EQ, UK
| | - Charlie Turner
- National Infection Service, Public Health England, Colindale, London, NW9 5EQ, UK
| | | | - Jamie Lopez-Bernal
- National Infection Service, Public Health England, Colindale, London, NW9 5EQ, UK
| | - Ross Harris
- National Infection Service, Public Health England, Colindale, London, NW9 5EQ, UK
| | - Andre Charlett
- National Infection Service, Public Health England, Colindale, London, NW9 5EQ, UK
| | - Gavin Dabrera
- National Infection Service, Public Health England, Colindale, London, NW9 5EQ, UK
| | - Meaghan Kall
- National Infection Service, Public Health England, Colindale, London, NW9 5EQ, UK
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25
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Chudasama DY, Tessier E, Flannagan J, Leeman D, Webster H, Demirjian A, Falconer C, Thelwall S, Kall M, Saliba V, Ramsay M, Dabrera G, Lamagni T. Surge in SARS-CoV-2 transmission in school-aged children and household contacts, England, August to October 2021. EURO SURVEILLANCE : BULLETIN EUROPEEN SUR LES MALADIES TRANSMISSIBLES = EUROPEAN COMMUNICABLE DISEASE BULLETIN 2021; 26. [PMID: 34857070 PMCID: PMC8641067 DOI: 10.2807/1560-7917.es.2021.26.48.2101019] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Easing of COVID-19 restrictions in England in the summer of 2021 was followed by a sharp rise in cases among school-aged children. Weekly rates of SARS-CoV-2 infection in primary and secondary school children reached 733.3 and 1,664.7/100,000 population, respectively, by week 39 2021. A surge in household clusters with school-aged index cases was noted at the start of the school term, with secondary cases predominantly in children aged 5–15 years and adults aged 30–49 years.
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Affiliation(s)
- Dimple Y Chudasama
- COVID-19 Epidemiology Cell, UK Health Security Agency, London, United Kingdom
| | - Elise Tessier
- COVID-19 Epidemiology Cell, UK Health Security Agency, London, United Kingdom
| | - Joe Flannagan
- COVID-19 Epidemiology Cell, UK Health Security Agency, London, United Kingdom
| | - David Leeman
- COVID-19 Epidemiology Cell, UK Health Security Agency, London, United Kingdom
| | - Harriet Webster
- COVID-19 Epidemiology Cell, UK Health Security Agency, London, United Kingdom
| | - Alicia Demirjian
- COVID-19 Epidemiology Cell, UK Health Security Agency, London, United Kingdom.,Paediatric Infectious Diseases and Immunology, Evelina London Children's Hospital, London, United Kingdom.,Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
| | - Catherine Falconer
- Clinical & Public Health, Young People Cell, UK Health Security Agency, London, United Kingdom
| | - Simon Thelwall
- COVID-19 Epidemiology Cell, UK Health Security Agency, London, United Kingdom
| | - Meaghan Kall
- COVID-19 Epidemiology Cell, UK Health Security Agency, London, United Kingdom
| | - Vanessa Saliba
- Surveillance Cell, UK Health Security Agency, London, United Kingdom
| | - Mary Ramsay
- Surveillance Cell, UK Health Security Agency, London, United Kingdom
| | - Gavin Dabrera
- COVID-19 Epidemiology Cell, UK Health Security Agency, London, United Kingdom
| | - Theresa Lamagni
- COVID-19 Epidemiology Cell, UK Health Security Agency, London, United Kingdom
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26
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Persistence of SARS-CoV-2-Specific Antibodies for 13 Months after Infection. Viruses 2021; 13:v13112313. [PMID: 34835119 PMCID: PMC8622371 DOI: 10.3390/v13112313] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Dynamics of antibody responses were investigated after a SARS-CoV-2 outbreak in a private company during the first wave of the pandemic. METHODS Workers of a sewing company (Lithuania) with known SARS-CoV-2 RT-PCR result during the outbreak (April 2020) were invited to participate in the study. Virus-specific IgG and IgM were monitored 2, 6 and 13 months after the outbreak via rapid IgG/IgM serological test and SARS-CoV-2 S protein-specific IgG ELISA. RESULTS Six months after the outbreak, 95% (CI 86-99%) of 59 previously infected individuals had virus-specific antibodies irrespective of the severity of infection. One-third of seropositive individuals had virus-specific IgM along with IgG indicating that IgM may persist for 6 months. Serological testing 13 months after the outbreak included 47 recovered individuals that remained non-vaccinated despite a wide accessibility of COVID-19 vaccines. The seropositivity rate was 83% (CI 69-91%) excluding one case of confirmed asymptomatic reinfection in this group. Between months 6 and 13, IgG levels either declined or remained stable in 31 individual and increased in 7 individuals possibly indicating an exposure to SARS-CoV-2 during the second wave of the pandemic. CONCLUSIONS Detectable levels of SARS-CoV-2-specific antibodies persist up to 13 months after infection for the majority of the cases.
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27
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Julin CH, Robertson AH, Hungnes O, Tunheim G, Bekkevold T, Laake I, Aune IF, Killengreen MF, Strand TR, Rykkvin R, Dorenberg DH, Stene-Johansen K, Berg ES, Bodin JE, Oftung F, Steens A, Næss LM. Household Transmission of SARS-CoV-2: A Prospective Longitudinal Study Showing Higher Viral Load and Increased Transmissibility of the Alpha Variant Compared to Previous Strains. Microorganisms 2021; 9:2371. [PMID: 34835495 PMCID: PMC8622435 DOI: 10.3390/microorganisms9112371] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/08/2021] [Accepted: 11/11/2021] [Indexed: 11/23/2022] Open
Abstract
We studied the secondary attack rate (SAR), risk factors, and precautionary practices of household transmission in a prospective, longitudinal study. We further compared transmission between the Alpha (B.1.1.7) variant and non-Variant of Concern (non-VOC) viruses. From May 2020 throughout April 2021, we recruited 70 confirmed COVID-19 cases with 146 household contacts. Participants donated biological samples eight times over 6 weeks and answered questionnaires. SARS-CoV-2 infection was detected by real-time RT-PCR. Whole genome sequencing and droplet digital PCR were used to establish virus variant and viral load. SARS-CoV-2 transmission occurred in 60% of the households, and the overall SAR for household contacts was 50%. The SAR was significantly higher for the Alpha variant (78%) compared with non-VOC viruses (43%) and was associated with a higher viral load. SAR was higher in household contacts aged ≥40 years (69%) than in younger contacts (40-47%), and for contacts of primary cases with loss of taste/smell. Children had lower viral loads and were more often asymptomatic than adults. Sleeping separately from the primary case reduced the risk of transmission. In conclusion, we found substantial household transmission, particularly for the Alpha variant. Precautionary practices seem to reduce SAR, but preventing household transmission may become difficult with more contagious variants, depending on vaccine use and effectiveness.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Lisbeth Meyer Næss
- Division of Infection Control, Norwegian Institute of Public Health, P.O. Box 222 Skøyen, 0213 Oslo, Norway; (C.H.J.); (A.H.R.); (O.H.); (G.T.); (T.B.); (I.L.); (I.F.A.); (M.F.K.); (T.R.S.); (R.R.); (D.H.D.); (K.S.-J.); (E.S.B.); (J.E.B.); (F.O.); (A.S.)
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28
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Bae SJ, Chung HS, Namgung M, Choi YH, Min JH, Lee DH. Comparison of the Clinical Process and Outcomes in Patients after Coronavirus Infection 2019 Outbreak. MEDICINA (KAUNAS, LITHUANIA) 2021; 57:medicina57101086. [PMID: 34684122 PMCID: PMC8538248 DOI: 10.3390/medicina57101086] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/04/2021] [Accepted: 10/05/2021] [Indexed: 12/28/2022]
Abstract
Background and Objectives: The coronavirus infection 2019 (COVID-19) pandemic has affected emergency department (ED) management. Its viral transmission necessitates the use of isolation rooms and personal protective equipment for treating suspected patients, such as those with fever. This delays the time until the first encounter with the patients, thereby increasing the length of stay (LOS) in the ED. We aimed to compare delays in the ED LOS and clinical processes between the COVID-19 period and pre-COVID-19 period. Moreover, we intended to evaluate if the aforementioned delay affected patient outcomes. Materials and Methods: We conducted a single-center, retrospective study in Korea. Patients with fever were compared between the “COVID-19 period” from March 2020 to August 2020 and the “pre-COVID-19 period” from March 2019 to September 2019. We compared the overall ED LOS and individual time variable, including initial diagnostic tests (laboratory tests, radiography), specific diagnostic test (computed tomography), and treatment processes (antibiotics). A logistic regression analysis was conducted to identify the association between hospital admission and patient data. Results: We enrolled 931 and 749 patients during pre- and COVID-19 periods, respectively. Patients with fever remained in the ED for a longer duration during the COVID-19 period (pre-COVID-19:207.7 ± 102.7 min vs. during COVID-19: 223.5 ± 119.4 min, p = 0.004). The total time for performing laboratory tests and radiography displayed significant differences between the two periods, particularly from the time of patient arrival in the ED to the time of issuing the order. The time until antibiotic administration was delayed in the COVID-19 period (pre-COVID-19:195.8 ± 103.3 min vs. during COVID-19: 216.9 ± 108.4 min, p = 0.003). The logistic regression analysis for hospital admission identified ED LOS as an independent factor in both periods. Conclusions: The delay until encountering patients with fever resulted in longer ED LOS during the COVID-19 period; however, it possibly did not increase the hospital admission rates.
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Affiliation(s)
- Sung-Jin Bae
- Department of Emergency Medicine, College of Medicine, Chung-Ang University, Seoul 06973, Korea
| | - Ho-Sub Chung
- Department of Emergency Medicine, College of Medicine, Chung-Ang University, Seoul 06973, Korea
- Department of Emergency Medicine, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul 07985, Korea
| | - Myeong Namgung
- Department of Emergency Medicine, College of Medicine, Chung-Ang University, Seoul 06973, Korea
| | - Yoon-Hee Choi
- Department of Emergency Medicine, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul 07985, Korea
| | - Jin-Hong Min
- Department of Emergency Medicine, College of Medicine, Chungnam National University, Daejeon 35015, Korea
| | - Dong-Hoon Lee
- Department of Emergency Medicine, College of Medicine, Chung-Ang University, Seoul 06973, Korea
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