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Perez-Guzman PN, Knock E, Imai N, Rawson T, Elmaci Y, Alcada J, Whittles LK, Thekke Kanapram D, Sonabend R, Gaythorpe KAM, Hinsley W, FitzJohn RG, Volz E, Verity R, Ferguson NM, Cori A, Baguelin M. Epidemiological drivers of transmissibility and severity of SARS-CoV-2 in England. Nat Commun 2023; 14:4279. [PMID: 37460537 PMCID: PMC10352350 DOI: 10.1038/s41467-023-39661-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 06/23/2023] [Indexed: 07/20/2023] Open
Abstract
As the SARS-CoV-2 pandemic progressed, distinct variants emerged and dominated in England. These variants, Wildtype, Alpha, Delta, and Omicron were characterized by variations in transmissibility and severity. We used a robust mathematical model and Bayesian inference framework to analyse epidemiological surveillance data from England. We quantified the impact of non-pharmaceutical interventions (NPIs), therapeutics, and vaccination on virus transmission and severity. Each successive variant had a higher intrinsic transmissibility. Omicron (BA.1) had the highest basic reproduction number at 8.3 (95% credible interval (CrI) 7.7-8.8). Varying levels of NPIs were crucial in controlling virus transmission until population immunity accumulated. Immune escape properties of Omicron decreased effective levels of immunity in the population by a third. Furthermore, in contrast to previous studies, we found Alpha had the highest basic infection fatality ratio (2.9%, 95% CrI 2.7-3.2), followed by Delta (2.2%, 95% CrI 2.0-2.4), Wildtype (1.2%, 95% CrI 1.1-1.2), and Omicron (0.7%, 95% CrI 0.6-0.8). Our findings highlight the importance of continued surveillance. Long-term strategies for monitoring and maintaining effective immunity against SARS-CoV-2 are critical to inform the role of NPIs to effectively manage future variants with potentially higher intrinsic transmissibility and severe outcomes.
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Affiliation(s)
- Pablo N Perez-Guzman
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Edward Knock
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Natsuko Imai
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Thomas Rawson
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Yasin Elmaci
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Joana Alcada
- Adult Intensive Care Unit, Royal Brompton Hospital, London, UK
- Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK
| | - Lilith K Whittles
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Divya Thekke Kanapram
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
- Department of Engineering, Division of Electrical Engineering, University of Cambridge, Cambridge, UK
| | - Raphael Sonabend
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Katy A M Gaythorpe
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Wes Hinsley
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Richard G FitzJohn
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Erik Volz
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Robert Verity
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Neil M Ferguson
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Anne Cori
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK
| | - Marc Baguelin
- MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College London, London, UK.
- National Institute for Health Research (NIHR) Health Protection Research Unit (HPRU) in Modelling and Health Economics, London, UK.
- Centre for Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK.
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Rawson T, Doohan P, Hauck K, Murray KA, Ferguson N. Climate change and communicable diseases in the Gulf Cooperation Council (GCC) countries. Epidemics 2023; 42:100667. [PMID: 36652872 DOI: 10.1016/j.epidem.2023.100667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 12/05/2022] [Accepted: 01/06/2023] [Indexed: 01/15/2023] Open
Abstract
A review of the extant literature reveals the extent to which the spread of communicable diseases will be significantly impacted by climate change. Specific research into how this will likely be observed in the countries of the Gulf Cooperation Council (GCC) is, however, greatly lacking. This report summarises the unique public health challenges faced by the GCC countries in the coming century, and outlines the need for greater investment in public health research and disease surveillance to better forecast the imminent epidemiological landscape. Significant data gaps currently exist regarding vector occurrence, spatial climate measures, and communicable disease case counts in the GCC - presenting an immediate research priority for the region. We outline policy work necessary to strengthen public health interventions, and to facilitate evidence-driven mitigation strategies. Such research will require a transdisciplinary approach, utilising existing cross-border public health initiatives, to ensure that such investigations are well-targeted and effectively communicated.
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Affiliation(s)
- Thomas Rawson
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK.
| | - Patrick Doohan
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Katharina Hauck
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Kris A Murray
- Centre on Climate Change and Planetary Health, MRC Unit The Gambia at London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, The Gambia
| | - Neil Ferguson
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
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Imai N, Rawson T, Knock ES, Sonabend R, Elmaci Y, Perez-Guzman PN, Whittles LK, Kanapram DT, Gaythorpe KAM, Hinsley W, Djaafara BA, Wang H, Fraser K, FitzJohn RG, Hogan AB, Doohan P, Ghani AC, Ferguson NM, Baguelin M, Cori A. Quantifying the effect of delaying the second COVID-19 vaccine dose in England: a mathematical modelling study. Lancet Public Health 2023; 8:e174-e183. [PMID: 36774945 PMCID: PMC9910835 DOI: 10.1016/s2468-2667(22)00337-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 12/09/2022] [Accepted: 12/14/2022] [Indexed: 02/11/2023]
Abstract
BACKGROUND The UK was the first country to start national COVID-19 vaccination programmes, initially administering doses 3 weeks apart. However, early evidence of high vaccine effectiveness after the first dose and the emergence of the SARS-CoV-2 alpha variant prompted the UK to extend the interval between doses to 12 weeks. In this study, we aimed to quantify the effect of delaying the second vaccine dose in England. METHODS We used a previously described model of SARS-CoV-2 transmission, calibrated to COVID-19 surveillance data from England, including hospital admissions, hospital occupancy, seroprevalence data, and population-level PCR testing data, using a Bayesian evidence-synthesis framework. We modelled and compared the epidemic trajectory in the counterfactual scenario in which vaccine doses were administered 3 weeks apart against the real reported vaccine roll-out schedule of 12 weeks. We estimated and compared the resulting numbers of daily infections, hospital admissions, and deaths. In sensitivity analyses, we investigated scenarios spanning a range of vaccine effectiveness and waning assumptions. FINDINGS In the period from Dec 8, 2020, to Sept 13, 2021, the number of individuals who received a first vaccine dose was higher under the 12-week strategy than the 3-week strategy. For this period, we estimated that delaying the interval between the first and second COVID-19 vaccine doses from 3 to 12 weeks averted a median (calculated as the median of the posterior sample) of 58 000 COVID-19 hospital admissions (291 000 cumulative hospitalisations [95% credible interval 275 000-319 000] under the 3-week strategy vs 233 000 [229 000-238 000] under the 12-week strategy) and 10 100 deaths (64 800 deaths [60 200-68 900] vs 54 700 [52 800-55 600]). Similarly, we estimated that the 3-week strategy would have resulted in more infections compared with the 12-week strategy. Across all sensitivity analyses the 3-week strategy resulted in a greater number of hospital admissions. In results by age group, the 12-week strategy led to more hospitalisations and deaths in older people in spring 2021, but fewer following the emergence of the delta variant during summer 2021. INTERPRETATION England's delayed-second-dose vaccination strategy was informed by early real-world data on vaccine effectiveness in the context of limited vaccine supplies in a growing epidemic. Our study shows that rapidly providing partial (single-dose) vaccine-induced protection to a larger proportion of the population was successful in reducing the burden of COVID-19 hospitalisations and deaths overall. FUNDING UK National Institute for Health Research; UK Medical Research Council; Community Jameel; Wellcome Trust; UK Foreign, Commonwealth and Development Office; Australian National Health and Medical Research Council; and EU.
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Affiliation(s)
- Natsuko Imai
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Thomas Rawson
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Edward S Knock
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK; National Institute for Health Research Health Protection Research Unit in Modelling Methodology, Imperial College London, UK Health Security Agency, London School of Hygiene & Tropical Medicine, London, UK
| | - Raphael Sonabend
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK; Department of Computer Science, Technische Universität Kaiserslautern, Kaiserslautern, Germany; Engineering Department, University of Cambridge, Cambridge, UK
| | - Yasin Elmaci
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Pablo N Perez-Guzman
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Lilith K Whittles
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Divya Thekke Kanapram
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Katy A M Gaythorpe
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Wes Hinsley
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Bimandra A Djaafara
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Haowei Wang
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Keith Fraser
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Richard G FitzJohn
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Alexandra B Hogan
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK; School of Population Health, University of New South Wales, Sydney, NSW, Australia
| | - Patrick Doohan
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Azra C Ghani
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Neil M Ferguson
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK; National Institute for Health Research Health Protection Research Unit in Modelling Methodology, Imperial College London, UK Health Security Agency, London School of Hygiene & Tropical Medicine, London, UK
| | - Marc Baguelin
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK; National Institute for Health Research Health Protection Research Unit in Modelling Methodology, Imperial College London, UK Health Security Agency, London School of Hygiene & Tropical Medicine, London, UK; Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Anne Cori
- Medical Research Council Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK; National Institute for Health Research Health Protection Research Unit in Modelling Methodology, Imperial College London, UK Health Security Agency, London School of Hygiene & Tropical Medicine, London, UK.
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Barin B, Kozlakidis Z, Ricci F, Su L, Tsioutis C, Welburn SC, Ropert C, Iosa M, Rawson T, Sun J, Lumbers ER. Editorial: Coronavirus Disease (COVID-19): Pathophysiology, Epidemiology, Clinical Management and Public Health Response, Volume II. Front Public Health 2022; 10:913507. [PMID: 35747774 PMCID: PMC9210928 DOI: 10.3389/fpubh.2022.913507] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 05/20/2022] [Indexed: 11/15/2022] Open
Affiliation(s)
- Burc Barin
- The Emmes Company, LLC, Rockville, MD, United States
| | - Zisis Kozlakidis
- International Agency for Research on Cancer, World Health Organization, Lyon, France
| | - Fabrizio Ricci
- Department of Neuroscience, Imaging and Clinical Sciences, G.d'Annunzio University of Chieti-Pescara, Chieti, Italy
| | - Longxiang Su
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | | | - Susan C. Welburn
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
| | - Catherine Ropert
- Department of Biochemistry and Immunology, Institute of Biological Sciences (ICB), Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Marco Iosa
- Department of Psychology, Sapienza University of Rome, Rome, Italy
- Smart Lab, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Thomas Rawson
- Medical Research Council (MRC) Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, United Kingdom
| | - Jiufeng Sun
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
| | - Eugenie R. Lumbers
- School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, University of Newcastle, Newcastle, NSW, Australia
- Pregnancy and Reproduction Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
- Priority Research Centre for Reproductive Sciences, University of Newcastle, Newcastle, NSW, Australia
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Rawson T. A hierarchical Bayesian quantitative microbiological risk assessment model for Salmonella in the sheep meat food chain. Food Microbiol 2022; 104:103975. [DOI: 10.1016/j.fm.2021.103975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/22/2021] [Accepted: 12/23/2021] [Indexed: 11/24/2022]
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Rawson T, Colles FM, Terry JCD, Bonsall MB. Mechanisms of biodiversity between
Campylobacter
sequence types in a flock of broiler–breeder chickens. Ecol Evol 2022; 12:e8651. [PMID: 35342550 PMCID: PMC8928907 DOI: 10.1002/ece3.8651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 01/12/2022] [Accepted: 01/28/2022] [Indexed: 01/26/2023] Open
Abstract
Commercial poultry flocks frequently harbor the dangerous bacterial pathogen Campylobacter. As exclusion efforts frequently fail, there is interest in potential ecologically informed solutions. A long‐term study of Campylobacter sequence types was used to investigate the competitive framework of the Campylobacter metacommunity and understand how multiple sequence types simultaneously co‐occur in a flock of chickens. A combination of matrix and patch‐occupancy models was used to estimate parameters describing the competition, transmission, and mortality of each sequence type. It was found that Campylobacter sequence types form a strong hierarchical framework within a flock of chickens and occupied a broad spectrum of transmission–mortality trade‐offs. Upon further investigation of how biodiversity is thus maintained within the flock, it was found that the demographic capabilities of Campylobacter, such as mortality and transmission, could not explain the broad biodiversity of sequence types seen, suggesting that external factors such as host‐bird health and seasonality are important elements in maintaining biodiversity of Campylobacter sequence types.
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Affiliation(s)
- Thomas Rawson
- Department of Zoology, Mathematical Ecology Research Group University of Oxford Oxford UK
| | - Frances M. Colles
- Department of Zoology Peter Medawar Building for Pathogen Research University of Oxford Oxford UK
- NIHR Health Protection Research Unit in Gastrointestinal Infections University of Oxford Oxford UK
| | | | - Michael B. Bonsall
- Department of Zoology, Mathematical Ecology Research Group University of Oxford Oxford UK
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Sonabend R, Whittles LK, Imai N, Perez-Guzman PN, Knock ES, Rawson T, Gaythorpe KAM, Djaafara BA, Hinsley W, FitzJohn RG, Lees JA, Kanapram DT, Volz EM, Ghani AC, Ferguson NM, Baguelin M, Cori A. Non-pharmaceutical interventions, vaccination, and the SARS-CoV-2 delta variant in England: a mathematical modelling study. Lancet 2021; 398:1825-1835. [PMID: 34717829 PMCID: PMC8550916 DOI: 10.1016/s0140-6736(21)02276-5] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/28/2021] [Accepted: 10/07/2021] [Indexed: 01/01/2023]
Abstract
BACKGROUND England's COVID-19 roadmap out of lockdown policy set out the timeline and conditions for the stepwise lifting of non-pharmaceutical interventions (NPIs) as vaccination roll-out continued, with step one starting on March 8, 2021. In this study, we assess the roadmap, the impact of the delta (B.1.617.2) variant of SARS-CoV-2, and potential future epidemic trajectories. METHODS This mathematical modelling study was done to assess the UK Government's four-step process to easing lockdown restrictions in England, UK. We extended a previously described model of SARS-CoV-2 transmission to incorporate vaccination and multi-strain dynamics to explicitly capture the emergence of the delta variant. We calibrated the model to English surveillance data, including hospital admissions, hospital occupancy, seroprevalence data, and population-level PCR testing data using a Bayesian evidence synthesis framework, then modelled the potential trajectory of the epidemic for a range of different schedules for relaxing NPIs. We estimated the resulting number of daily infections and hospital admissions, and daily and cumulative deaths. Three scenarios spanning a range of optimistic to pessimistic vaccine effectiveness, waning natural immunity, and cross-protection from previous infections were investigated. We also considered three levels of mixing after the lifting of restrictions. FINDINGS The roadmap policy was successful in offsetting the increased transmission resulting from lifting NPIs starting on March 8, 2021, with increasing population immunity through vaccination. However, because of the emergence of the delta variant, with an estimated transmission advantage of 76% (95% credible interval [95% CrI] 69-83) over alpha, fully lifting NPIs on June 21, 2021, as originally planned might have led to 3900 (95% CrI 1500-5700) peak daily hospital admissions under our central parameter scenario. Delaying until July 19, 2021, reduced peak hospital admissions by three fold to 1400 (95% CrI 700-1700) per day. There was substantial uncertainty in the epidemic trajectory, with particular sensitivity to the transmissibility of delta, level of mixing, and estimates of vaccine effectiveness. INTERPRETATION Our findings show that the risk of a large wave of COVID-19 hospital admissions resulting from lifting NPIs can be substantially mitigated if the timing of NPI relaxation is carefully balanced against vaccination coverage. However, with the delta variant, it might not be possible to fully lift NPIs without a third wave of hospital admissions and deaths, even if vaccination coverage is high. Variants of concern, their transmissibility, vaccine uptake, and vaccine effectiveness must be carefully monitored as countries relax pandemic control measures. FUNDING National Institute for Health Research, UK Medical Research Council, Wellcome Trust, and UK Foreign, Commonwealth and Development Office.
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Affiliation(s)
- Raphael Sonabend
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Lilith K Whittles
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK; National Institute for Health Research Health Protection Research Unit in Modelling Methodology, Imperial College London, Public Health England, London School of Hygiene & Tropical Medicine, London, UK; Modelling and Economics Unit, National Infection Service, Public Health England, London, UK
| | - Natsuko Imai
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Pablo N Perez-Guzman
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Edward S Knock
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK; National Institute for Health Research Health Protection Research Unit in Modelling Methodology, Imperial College London, Public Health England, London School of Hygiene & Tropical Medicine, London, UK
| | - Thomas Rawson
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Katy A M Gaythorpe
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Bimandra A Djaafara
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Wes Hinsley
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Richard G FitzJohn
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - John A Lees
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Divya Thekke Kanapram
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Erik M Volz
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Azra C Ghani
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Neil M Ferguson
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK; National Institute for Health Research Health Protection Research Unit in Modelling Methodology, Imperial College London, Public Health England, London School of Hygiene & Tropical Medicine, London, UK.
| | - Marc Baguelin
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK; National Institute for Health Research Health Protection Research Unit in Modelling Methodology, Imperial College London, Public Health England, London School of Hygiene & Tropical Medicine, London, UK; Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Anne Cori
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK; National Institute for Health Research Health Protection Research Unit in Modelling Methodology, Imperial College London, Public Health England, London School of Hygiene & Tropical Medicine, London, UK.
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8
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Huntingford C, Rawson T, Bonsall MB. Optimal COVID-19 Vaccine Sharing Between Two Nations That Also Have Extensive Travel Exchanges. Front Public Health 2021; 9:633144. [PMID: 34458218 PMCID: PMC8387873 DOI: 10.3389/fpubh.2021.633144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 07/08/2021] [Indexed: 01/12/2023] Open
Abstract
Countries around the world have observed reduced infections from the SARS-CoV-2 virus, that causes COVID-19 illness, primarily due to non-pharmaceutical interventions (NPIs) such as lockdowns and social distancing measures designed to limit physical proximity between people. However, economies and societal interactions require restarting, and so lockdowns cannot continue indefinitely. Therefore, much hope is placed in using newly developed vaccines as a route back to normality, but this raises key questions about how they are shared. There are also emerging questions regarding travel. For instance, international business and trade necessitates at least some in-person exchanges, alongside restarting travel also for tourist purposes. By utilising a Susceptible-Infected-Recovered-Vaccinated (SIRV) mathematical model, we simulate the populations of two nations in parallel, where the first nation produces a vaccine and decides the extent to which it is shared with the second. Overlaying our mathematical structure is the virus-related effects of travel between the two nations. We find that even with extensive travel, nation one minimises its total number of deaths by simply retaining vaccines, aiming for full inoculation as fast as possible, suggesting that the risks posed by travel can be mitigated by rapidly vaccinating its own population. If instead we consider the total deaths i.e., sum of deaths of both nations, then such a policy of not sharing by nation one until full vaccination is highly sub-optimal. A policy of low initial sharing causes many more deaths in nation two than lives saved in nation one, raising important ethical issues. This imbalance in the health impact of vaccination provision must be considered as some countries begin to approach the point of extensive vaccination, while others lack the resources to do so.
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Affiliation(s)
| | - Thomas Rawson
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Michael B Bonsall
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
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Amit AML, Pepito VCF, Gutierrez B, Rawson T. Data Sharing in Southeast Asia During the First Wave of the COVID-19 Pandemic. Front Public Health 2021; 9:662842. [PMID: 34222173 PMCID: PMC8242246 DOI: 10.3389/fpubh.2021.662842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 05/11/2021] [Indexed: 11/13/2022] Open
Abstract
Background: When a new pathogen emerges, consistent case reporting is critical for public health surveillance. Tracking cases geographically and over time is key for understanding the spread of an infectious disease and effectively designing interventions to contain and mitigate an epidemic. In this paper we describe the reporting systems on COVID-19 in Southeast Asia during the first wave in 2020, and highlight the impact of specific reporting methods. Methods: We reviewed key epidemiological variables from various sources including a regionally comprehensive dataset, national trackers, dashboards, and case bulletins for 11 countries during the first wave of the epidemic in Southeast Asia. We recorded timelines of shifts in epidemiological reporting systems and described the differences in how epidemiological data are reported across countries and timepoints. Results: Our findings suggest that countries in Southeast Asia generally reported precise and detailed epidemiological data during the first wave of the pandemic. Changes in reporting rarely occurred for demographic data, while reporting shifts for geographic and temporal data were frequent. Most countries provided COVID-19 individual-level data daily using HTML and PDF, necessitating scraping and extraction before data could be used in analyses. Conclusion: Our study highlights the importance of more nuanced analyses of COVID-19 epidemiological data within and across countries because of the frequent shifts in reporting. As governments continue to respond to impacts on health and the economy, data sharing also needs to be prioritised given its foundational role in policymaking, and in the implementation and evaluation of interventions.
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Affiliation(s)
- Arianna Maever L Amit
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States.,School of Medicine and Public Health, Ateneo de Manila University, Pasig, Philippines.,College of Medicine, University of the Philippines Manila, Manila, Philippines
| | | | - Bernardo Gutierrez
- Department of Zoology, University of Oxford, Oxford, United Kingdom.,School of Biological and Environmental Sciences, Universidad San Francisco de Quito USFQ, Quito, Ecuador
| | - Thomas Rawson
- Department of Zoology, University of Oxford, Oxford, United Kingdom
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Rawson T, Huntingford C, Bonsall MB. Temporary "Circuit Breaker" Lockdowns Could Effectively Delay a COVID-19 Second Wave Infection Peak to Early Spring. Front Public Health 2020; 8:614945. [PMID: 33365299 PMCID: PMC7750327 DOI: 10.3389/fpubh.2020.614945] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/18/2020] [Indexed: 11/13/2022] Open
Affiliation(s)
- Thomas Rawson
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | - Michael B. Bonsall
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
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Rawson T, Paton RS, Colles FM, Maiden MCJ, Dawkins MS, Bonsall MB. A Mathematical Modeling Approach to Uncover Factors Influencing the Spread of Campylobacter in a Flock of Broiler-Breeder Chickens. Front Microbiol 2020; 11:576646. [PMID: 33193192 PMCID: PMC7655537 DOI: 10.3389/fmicb.2020.576646] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/15/2020] [Indexed: 01/05/2023] Open
Abstract
Despite continued efforts to improve biosecurity protocols, Campylobacter continues to be detected in the majority of commercial chicken flocks across Europe. Using an extensive data set of Campylobacter prevalence within a chicken breeder flock for over a year, multiple Bayesian models are presented to explore the dynamics of the spread of Campylobacter in response to seasonal variation, species-specificity, bird health, and total colonization prevalence. These models indicated that birds within the flock varied greatly in their response to bacterial challenge, and that this phenomenon had a large impact on the overall prevalence of different species of Campylobacter. Campylobacter jejuni appeared more frequently in the summer, while Campylobacter coli persisted for a longer duration, amplified by the most susceptible birds in the flock. Our study suggests that strains of Campylobacter that appear most frequently likely possess no demographic advantage, but are instead amplified due to the health of the birds that ingest it.
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Affiliation(s)
- Thomas Rawson
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Robert Stephen Paton
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Frances M. Colles
- Peter Medawar Building for Pathogen Research, Department of Zoology, University of Oxford, Oxford, United Kingdom
- National Institute for Health Research, Health Protection Research Unit in Gastrointestinal Infections, University of Oxford, Oxford, United Kingdom
| | - Martin C. J. Maiden
- Peter Medawar Building for Pathogen Research, Department of Zoology, University of Oxford, Oxford, United Kingdom
- National Institute for Health Research, Health Protection Research Unit in Gastrointestinal Infections, University of Oxford, Oxford, United Kingdom
| | - Marian Stamp Dawkins
- Department of Zoology, John Krebs Field Station, University of Oxford, Oxford, United Kingdom
| | - Michael B. Bonsall
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
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Rawson T, Brewer T, Veltcheva D, Huntingford C, Bonsall MB. How and When to End the COVID-19 Lockdown: An Optimization Approach. Front Public Health 2020; 8:262. [PMID: 32587844 PMCID: PMC7298102 DOI: 10.3389/fpubh.2020.00262] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 05/22/2020] [Indexed: 01/10/2023] Open
Abstract
Countries around the world are in a state of lockdown to help limit the spread of SARS-CoV-2. However, as the number of new daily confirmed cases begins to decrease, governments must decide how to release their populations from quarantine as efficiently as possible without overwhelming their health services. We applied an optimal control framework to an adapted Susceptible-Exposure-Infection-Recovery (SEIR) model framework to investigate the efficacy of two potential lockdown release strategies, focusing on the UK population as a test case. To limit recurrent spread, we find that ending quarantine for the entire population simultaneously is a high-risk strategy, and that a gradual re-integration approach would be more reliable. Furthermore, to increase the number of people that can be first released, lockdown should not be ended until the number of new daily confirmed cases reaches a sufficiently low threshold. We model a gradual release strategy by allowing different fractions of those in lockdown to re-enter the working non-quarantined population. Mathematical optimization methods, combined with our adapted SEIR model, determine how to maximize those working while preventing the health service from being overwhelmed. The optimal strategy is broadly found to be to release approximately half the population 2-4 weeks from the end of an initial infection peak, then wait another 3-4 months to allow for a second peak before releasing everyone else. We also modeled an "on-off" strategy, of releasing everyone, but re-establishing lockdown if infections become too high. We conclude that the worst-case scenario of a gradual release is more manageable than the worst-case scenario of an on-off strategy, and caution against lockdown-release strategies based on a threshold-dependent on-off mechanism. The two quantities most critical in determining the optimal solution are transmission rate and the recovery rate, where the latter is defined as the fraction of infected people in any given day that then become classed as recovered. We suggest that the accurate identification of these values is of particular importance to the ongoing monitoring of the pandemic.
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Affiliation(s)
- Thomas Rawson
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Tom Brewer
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Dessislava Veltcheva
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | - Michael B. Bonsall
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
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Rawson T, Wilkins KE, Bonsall MB. Optimal control approaches for combining medicines and mosquito control in tackling dengue. R Soc Open Sci 2020; 7:181843. [PMID: 32431854 PMCID: PMC7211884 DOI: 10.1098/rsos.181843] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 03/23/2020] [Indexed: 05/03/2023]
Abstract
Dengue is a debilitating and devastating viral infection spread by mosquito vectors, and over half the world's population currently live at risk of dengue (and other flavivirus) infections. Here, we use an integrated epidemiological and vector ecology framework to predict optimal approaches for tackling dengue. Our aim is to investigate how vector control and/or vaccination strategies can be best combined and implemented for dengue disease control on small networks, and whether these optimal strategies differ under different circumstances. We show that a combination of vaccination programmes and the release of genetically modified self-limiting mosquitoes (comparable to sterile insect approaches) is always considered the most beneficial strategy for reducing the number of infected individuals, owing to both methods having differing impacts on the underlying disease dynamics. Additionally, depending on the impact of human movement on the disease dynamics, the optimal way to combat the spread of dengue is to focus prevention efforts on large population centres. Using mathematical frameworks, such as optimal control, are essential in developing predictive management and mitigation strategies for dengue disease control.
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Affiliation(s)
- Thomas Rawson
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford OX1 3PS, UK
- Author for correspondence: Thomas Rawson e-mail:
| | - Kym E. Wilkins
- School of Mathematical Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Michael B. Bonsall
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford OX1 3PS, UK
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Abstract
Globally, the bacterial genus Campylobacter is one of the leading causes of human gastroenteritis, with its primary route of infection being through poultry meat. The application of biosecurity measures is currently limited by a lack of understanding of the transmission dynamics within a flock. Our work is the first to undertake a mathematical modeling approach to Campylobacter population dynamics within a flock of broilers (chickens bred specifically for meat). A system of stochastic differential equations is used to model the routes of infection between co-housed birds. The presented model displays the strong correlation between housing density and Campylobacter prevalence, and shows how stochastic variation is the driving factor determining which strains of Campylobacter will emerge first within a flock. The model also shows how the system will rapidly select for phenotypic advantages, to quickly eliminate demographically-weaker strains. A global sensitivity analysis is performed, highlighting that the growth and death rate of other native bacterial species likely contributes the greatest to preventing flock outbreaks, presenting a promising approach to hypothesizing new methods of combatting disease transmission.
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Affiliation(s)
- Thomas Rawson
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Marian Stamp Dawkins
- Department of Zoology, University of Oxford, John Krebs Field Station, Oxford, United Kingdom
| | - Michael B. Bonsall
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
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Lee L, Hanan E, Zhou A, Rawson T, Li J, Kholi PB, Barrett K, Chang C, Chen J, Ubhayakar S, Siu M, Kenny J, Blair W, Ghilardi N, Sampath D. Abstract A20: Development and validation of a novel acute myeloid leukemia xenograft model that is dependent on the JAK2V617F mutation for growth in vivo. Mol Cancer Ther 2009. [DOI: 10.1158/1535-7163.targ-09-a20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: The Janus-associated kinase (JAK) proteins are a family of non-receptor tyrosine kinases (JAK1, JAK2, JAK3, and TYK2) that play an important role in cellular survival, proliferation, and differentiation. A gain of function mutation (V617F) in the pseudo-kinase domain of JAK2 is detected at high frequency in Philadelphia-negative myeloproliferative disorders such as polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis. To further elucidate the role of JAK2V617F on cell growth in vivo we established and validated a novel xenograft model using the acute myeloid leukemia cell line, SET2, which is heterozygous for the mutation.
Materials and Methods: SET2 cells containing stable doxycycline-inducible JAK2V617F shRNA clones were generated by lentiviral transduction. Cell proliferation and viability were assessed by incorporation of 3H-Thymidine or by ATP quantitation. Cell-cycle and apoptosis markers were evaluated by Western blotting using antibodies against cyclin D1, PIM1, cleaved caspase 3 and 7 and PARP. Phospho-STAT5 and total STAT5 were measured using both western blotting and ELISA. A SET2 shRNA clone was selected for in vivo growth in SCID beige female mice and treated with doxycycline or a JAK2 inhibitor (JAK2i). Plasma and tumor drug levels were measured by LC/MS.
Results: Genetic knockdown using a doxycycline-inducible JAK2V617F shRNA confirmed SET2 cells are dependent on this gain of function mutation for growth based on inhibition of cell proliferation in the presence of doxycycline. The latter was corroborated with a selective JAK2i (Ki= 4nM) that potently inhibited SET2 cell viability (EC50 = 355nM). The JAK2i rapidly suppressed phosphorylation of STAT5 (EC50 = 313nM) and induced cycle arrest at the G0–G1 phase based on downregulation of cyclin D1 expression. The JAK2i also effectively inhibited expression of PIM-1 kinase, a STAT5 target gene, and activated cleavage of procaspase 3 and 7 and DNA-repair enzyme PARP to induce apoptosis in a time- and dose-dependent manner. A SET2 xenograft model was established by in vivo selection of a variant of the doxycycline- JAK2V617F shRNA parental cell line. Its dependence on JAK2V617F was confirmed by treatment with doxcycline and oral administration of a JAK2i, which resulted in significant tumor growth inhibition in vivo. Investigation of the PK/PD relationship underlying the activity of JAK2i provided direct evidence of phospho-STAT5 suppression and induction of apoptosis for its antitumor effect in vivo. Plasma drug levels correlated with the duration and magnitude of suppression.
Conclusion: A JAK2V617F dependent SET2 xenograft model has been established and validated by shRNA gene knockdown and pharmacologically with a JAK2i in vivo. JAK2V617F inhibition results in suppression of STAT5 phosphorylation, cell-cycle arrest and induction of apoptosis in vitro and in vivo.
Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A20.
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Affiliation(s)
- Leslie Lee
- Genentech, Inc., South San Francisco, CA
| | | | - Aihe Zhou
- Genentech, Inc., South San Francisco, CA
| | | | - Ji Li
- Genentech, Inc., South San Francisco, CA
| | | | | | | | - Jacob Chen
- Genentech, Inc., South San Francisco, CA
| | | | - Mike Siu
- Genentech, Inc., South San Francisco, CA
| | - Jane Kenny
- Genentech, Inc., South San Francisco, CA
| | - Wade Blair
- Genentech, Inc., South San Francisco, CA
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Olivero AG, Eigenbrot C, Goldsmith R, Robarge K, Artis DR, Flygare J, Rawson T, Sutherlin DP, Kadkhodayan S, Beresini M, Elliott LO, DeGuzman GG, Banner DW, Ultsch M, Marzec U, Hanson SR, Refino C, Bunting S, Kirchhofer D. A selective, slow binding inhibitor of factor VIIa binds to a nonstandard active site conformation and attenuates thrombus formation in vivo. J Biol Chem 2005; 280:9160-9. [PMID: 15632123 DOI: 10.1074/jbc.m409068200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The serine protease factor VIIa (FVIIa) in complex with its cellular cofactor tissue factor (TF) initiates the blood coagulation reactions. TF.FVIIa is also implicated in thrombosis-related disorders and constitutes an appealing therapeutic target for treatment of cardiovascular diseases. To this end, we generated the FVIIa active site inhibitor G17905, which displayed great potency toward TF.FVIIa (Ki = 0.35 +/- 0.11 nM). G17905 did not appreciably inhibit 12 of the 14 examined trypsin-like serine proteases, consistent with its TF.FVIIa-specific activity in clotting assays. The crystal structure of the FVIIa.G17905 complex provides insight into the molecular basis of the high selectivity. It shows that, compared with other serine proteases, FVIIa is uniquely equipped to accommodate conformational disturbances in the Gln217-Gly219 region caused by the ortho-hydroxy group of the inhibitor's aminobenzamidine moiety located in the S1 recognition pocket. Moreover, the structure revealed a novel, nonstandard conformation of FVIIa active site in the region of the oxyanion hole, a "flipped" Lys192-Gly193 peptide bond. Macromolecular substrate activation assays demonstrated that G17905 is a noncompetitive, slow-binding inhibitor. Nevertheless, G17905 effectively inhibited thrombus formation in a baboon arterio-venous shunt model, reducing platelet and fibrin deposition by approximately 70% at 0.4 mg/kg + 0.1 mg/kg/min infusion. Therefore, the in vitro potency of G17905, characterized by slow binding kinetics, correlated with efficacious antithrombotic activity in vivo.
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Affiliation(s)
- Alan G Olivero
- Department of Medicinal Chemistry, Genentech, Inc., South San Francisco, California 94080, USA
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McDowell RS, Blackburn BK, Gadek TR, McGee LR, Rawson T, Reynolds ME, Robarge KD, Somers TC, Thorsett ED. From Peptide to Non-Peptide. 2. The de Novo Design of Potent, Non-peptidal Inhibitors of Platelet Aggregation Based on a Benzodiazepinedione Scaffold. J Am Chem Soc 2002. [DOI: 10.1021/ja00091a008] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Rawson T, Raggio D. Neurodevelopmental outcome of low birthweight infants using corrected and uncorrected scores on the Vineland Adaptive Behavior Scales and Bayley Scales of Infant Development-Second edition. Arch Clin Neuropsychol 2000. [DOI: 10.1093/arclin/15.8.798a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Rawson T. Neurodevelopmental outcome of low birthweight infants using corrected and uncorrected scores on the Vineland Adaptive Behavior Scales and Bayley Scales of Infant Development-Second edition. Arch Clin Neuropsychol 2000. [DOI: 10.1016/s0887-6177(00)80270-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Jackson DY, Quan C, Artis DR, Rawson T, Blackburn B, Struble M, Fitzgerald G, Chan K, Mullins S, Burnier JP, Fairbrother WJ, Clark K, Berisini M, Chui H, Renz M, Jones S, Fong S. Potent alpha 4 beta 1 peptide antagonists as potential anti-inflammatory agents. J Med Chem 1997; 40:3359-68. [PMID: 9341911 DOI: 10.1021/jm970175s] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The migration, adhesion, and subsequent extravasation of leukocytes into inflamed tissues contribute to the pathogenesis of a variety of inflammatory diseases including asthma, rheumatoid arthritis, inflammatory bowel disease, and multiple sclerosis. The integrin adhesion receptor alpha 4 beta 1 expressed on leukocytes binds to the extracellular matrix protein fibronectin and to the cytokine inducible vascular cell adhesion molecule-1 (VCAM-1) at inflamed sites. Binding of alpha 4 beta 1 to VCAM-1 initiates firm adhesion of the leukocyte to the vascular endothelium followed by extravasation into the tissue. Monoclonal antibodies generated against either alpha 4 beta 1 or VCAM-1 can moderate this inflammatory response in a variety of animal models. Recently peptides containing a consensus LDV sequence based on the connecting segment-1 (CS-1) of fibronectin and cyclic peptides containing an RCD motif have shown promise in modulating leukocyte migration and inflammation presumably by blocking the interaction of alpha 4 beta 1 with VCAM-1. Here we describe novel, highly potent, cyclic peptides that competitively inhibit alpha 4 beta 1 binding to VCAM-1 and fibronectin at sub nanomolar concentrations. The structure of a representative analog was determined via NMR spectroscopy and used to facilitate optimization of peptide leads. The peptides discussed here utilize similar functional groups as the binding epitope of VCAM-1, inhibit lymphocyte migration in vivo, and are highly selective for alpha 4 beta 1. Furthermore the structure--activity relationships described here have provided a template for the structure-based design of small molecule antagonists of alpha 4 beta 1-mediated cell adhesion processes.
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MESH Headings
- Animals
- Anti-Inflammatory Agents, Non-Steroidal/chemical synthesis
- Anti-Inflammatory Agents, Non-Steroidal/chemistry
- Anti-Inflammatory Agents, Non-Steroidal/metabolism
- Anti-Inflammatory Agents, Non-Steroidal/pharmacology
- Antibodies, Monoclonal/immunology
- Binding, Competitive
- Cell Adhesion/drug effects
- Cell Movement/drug effects
- Integrin alpha4beta1
- Integrins/antagonists & inhibitors
- Integrins/immunology
- Integrins/metabolism
- Lymphocytes/drug effects
- Lymphocytes/physiology
- Magnetic Resonance Spectroscopy
- Mass Spectrometry
- Mice
- Models, Molecular
- Molecular Structure
- Peptides, Cyclic/chemical synthesis
- Peptides, Cyclic/chemistry
- Peptides, Cyclic/metabolism
- Peptides, Cyclic/pharmacology
- Receptors, Lymphocyte Homing/antagonists & inhibitors
- Receptors, Lymphocyte Homing/immunology
- Receptors, Lymphocyte Homing/metabolism
- Structure-Activity Relationship
- Vascular Cell Adhesion Molecule-1/chemistry
- Vascular Cell Adhesion Molecule-1/immunology
- Vascular Cell Adhesion Molecule-1/metabolism
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Affiliation(s)
- D Y Jackson
- Department of Bioorganic Chemistry, Genentech Inc., South San Francisco, California 94080, USA
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