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Carlson CJ, Garnier R, Tiu A, Luby SP, Bansal S. Strategic vaccine stockpiles for regional epidemics of emerging viruses: A geospatial modeling framework. Vaccine 2024; 42:126051. [PMID: 38902187 DOI: 10.1016/j.vaccine.2024.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 06/03/2024] [Accepted: 06/05/2024] [Indexed: 06/22/2024]
Abstract
Multinational epidemics of emerging infectious diseases are increasingly common, due to anthropogenic pressure on ecosystems and the growing connectivity of human populations. Early and efficient vaccination can contain outbreaks and prevent mass mortality, but optimal vaccine stockpiling strategies are dependent on pathogen characteristics, reservoir ecology, and epidemic dynamics. Here, we model major regional outbreaks of Nipah virus and Middle East respiratory syndrome, and use these to develop a generalized framework for estimating vaccine stockpile needs based on spillover geography, spatially-heterogeneous healthcare capacity and spatially-distributed human mobility networks. Because outbreak sizes were highly skewed, we found that most outbreaks were readily contained (median stockpile estimate for MERS-CoV: 2,089 doses; Nipah: 1,882 doses), but the maximum estimated stockpile need in a highly unlikely large outbreak scenario was 2-3 orders of magnitude higher (MERS-CoV: ∼87,000 doses; Nipah ∼ 1.1 million doses). Sensitivity analysis revealed that stockpile needs were more dependent on basic epidemiological parameters (i.e., death and recovery rate) and healthcare availability than any uncertainty related to vaccine efficacy or deployment strategy. Our results highlight the value of descriptive epidemiology for real-world modeling applications, and suggest that stockpile allocation should consider ecological, epidemiological, and social dimensions of risk.
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Affiliation(s)
- Colin J Carlson
- Department of Biology, Georgetown University; Department of Epidemiology of Microbial Diseases, Yale University School of Public Health
| | | | - Andrew Tiu
- Department of Biology, Georgetown University
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2
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Ahmad B, Sagide M, Ntamwinja S, Byiringiro E, Kihanduka E, Rugendabanga E, Hangi S, Bhattacharjee P, Ali B, Nkundakozera M, Kanda MS, Guruka L, Onesime J, Tague C, Langat AK, Akilimali A. National burden of Ebola virus disease in Democratic Republic of the Congo: the urgency to act. Ann Med Surg (Lond) 2024; 86:4579-4585. [PMID: 39118744 PMCID: PMC11305799 DOI: 10.1097/ms9.0000000000002213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Accepted: 05/15/2024] [Indexed: 08/10/2024] Open
Abstract
Ebola virus disease (EVD) has long been a major public health concern for Democratic Republic of the Congo (DR Congo). First identified in DR Congo in 1976, the country has witnessed more than 25 outbreaks of this deadly disease, which has a case fatality rate of nearly 90% and manifesting with symptoms such as diarrhoea, vomiting, stomachache and haemorrhagic fever. African fruit bats have been speculated to be the reservoir of this virus. DR Congo is currently facing another EVD outbreak simultaneously with other communicable diseases, rendering it vulnerable to a shortage of medical and paramedical staff along with distrust among remote communities towards local authorities due to armed conflict and political instability. Moreover, lack of ring vaccinations and inefficient surveillance of suspected individuals are some other significant hurdles in disease control. Despite the availability of rVSV-ZEBOV/Erbevo vaccine and many antibody-based vaccines, challenges including politicization, low access to remote communities, and illiteracy have limited their effectiveness. Recently, the Congolese govt. has put in efforts such as building local capacities at the health zone level, outbreak control intervention, community engagement and social mobilization to counter the rising EVD cases. Four successive Strategic Response Plans have been implemented to increase resource mobilization by DR Congo and her partners. The Spread of zoonotics such as EVD can be confronted by implementing the One Health approach, which involves medical staff, veterinarians and public health officials.
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Affiliation(s)
- Bilal Ahmad
- Department of Community Medicine and Public Health, Shaikh Khalifa bin Zayed Al Nahyan Medical and Dental College
| | - Martin Sagide
- Jomo Kenyatta University of Agriculture and Technology, Juja
| | | | - Elysée Byiringiro
- Department of Internal Medicine, Kibagabaga District Hospital, Kigali, Rwanda
- Department of Research, Medical Research Circle (MedReC), Bukavu
| | - Elie Kihanduka
- Department of Research, Medical Research Circle (MedReC), Bukavu
| | | | - Samson Hangi
- Department of Research, Medical Research Circle (MedReC), Bukavu
- Faculty of Medicine, La Sapientia Catholic University
| | | | - Babar Ali
- The University of Lahore
- University Institute of Radiological Sciences and Medical Imaging Technology, Lahore, Pakistan
| | | | | | | | - Jones Onesime
- Department of Research, Medical Research Circle (MedReC), Bukavu
| | - Christian Tague
- Faculty of Medicine, Université Libre des Pays des Grands Lacs, Goma
| | - Amos Kipkorir Langat
- Pan African University for Basic Sciences Technology and innovation, Nairobi, Kenya
| | - Aymar Akilimali
- Department of Research, Medical Research Circle (MedReC), Bukavu
- SCORE, Medical Students Association of DR Congo
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Ko Y, Lee J, Seo Y, Jung E. A comprehensive analysis of non-pharmaceutical interventions and vaccination on Ebolavirus disease outbreak: Stochastic modeling approach. PLoS Negl Trop Dis 2024; 18:e0011955. [PMID: 38848434 PMCID: PMC11189251 DOI: 10.1371/journal.pntd.0011955] [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: 02/01/2024] [Revised: 06/20/2024] [Accepted: 05/16/2024] [Indexed: 06/09/2024] Open
Abstract
Ebolavirus disease (EVD) outbreaks have intermittently occurred since the first documented case in the 1970s. Due to its transmission characteristics, large outbreaks have not been observed outside Africa. However, within the continent, significant outbreaks have been attributed to factors such as endemic diseases with similar symptoms and inadequate medical infrastructure, which complicate timely diagnosis. In this study, we employed a stochastic modeling approach to analyze the spread of EVD during the early stages of an outbreak, with an emphasis on inherent risks. We developed a model that considers healthcare workers and unreported cases, and assessed the effect of non-pharmaceutical interventions (NPIs) using actual data. Our results indicate that the implementation of NPIs led to a decrease in the transmission rate and infectious period by 30% and 40% respectively, following the declaration of the outbreak. We also investigated the risks associated with delayed outbreak recognition. Our simulations suggest that, when accounting for NPIs and recognition delays, prompt detection could have resulted in a similar outbreak scale, with approximately 50% of the baseline NPIs effect. Finally, we discussed the potential effects of a vaccination strategy as a follow-up measure after the outbreak declaration. Our findings suggest that a vaccination strategy can reduce both the burden of NPIs and the scale of the outbreak.
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Affiliation(s)
- Youngsuk Ko
- Department of Mathematics, Konkuk University, Seoul, Korea
| | - Jacob Lee
- Division of Infectious Disease, Hallym University College of Medicine, Seoul, Korea
| | - Yubin Seo
- Division of Infectious Disease, Hallym University College of Medicine, Seoul, Korea
| | - Eunok Jung
- Department of Mathematics, Konkuk University, Seoul, Korea
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Schäfer A, Marzi A, Furuyama W, Catanzaro NJ, Nguyen C, Haddock E, Feldmann F, Meade-White K, Thomas T, Hubbard ML, Gully KL, Leist SR, Hock P, Bell TA, De la Cruz GE, Midkiff BR, Martinez DR, Shaw GD, Miller DR, Vernon MJ, Graham RL, Cowley DO, Montgomery SA, Schughart K, de Villena FPM, Wilkerson GK, Ferris MT, Feldmann H, Baric RS. Mapping of susceptibility loci for Ebola virus pathogenesis in mice. Cell Rep 2024; 43:114127. [PMID: 38652660 PMCID: PMC11348656 DOI: 10.1016/j.celrep.2024.114127] [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: 04/11/2023] [Revised: 03/11/2024] [Accepted: 04/03/2024] [Indexed: 04/25/2024] Open
Abstract
Ebola virus (EBOV), a major global health concern, causes severe, often fatal EBOV disease (EVD) in humans. Host genetic variation plays a critical role, yet the identity of host susceptibility loci in mammals remains unknown. Using genetic reference populations, we generate an F2 mapping cohort to identify host susceptibility loci that regulate EVD. While disease-resistant mice display minimal pathogenesis, susceptible mice display severe liver pathology consistent with EVD-like disease and transcriptional signatures associated with inflammatory and liver metabolic processes. A significant quantitative trait locus (QTL) for virus RNA load in blood is identified in chromosome (chr)8, and a severe clinical disease and mortality QTL is mapped to chr7, which includes the Trim5 locus. Using knockout mice, we validate the Trim5 locus as one potential driver of liver failure and mortality after infection. The identification of susceptibility loci provides insight into molecular genetic mechanisms regulating EVD progression and severity, potentially informing therapeutics and vaccination strategies.
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Affiliation(s)
- Alexandra Schäfer
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Andrea Marzi
- Laboratory of Virology, Division of Intramural Research, NIAID, NIH, Hamilton, MT 59840, USA.
| | - Wakako Furuyama
- Laboratory of Virology, Division of Intramural Research, NIAID, NIH, Hamilton, MT 59840, USA
| | - Nicholas J Catanzaro
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Cameron Nguyen
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Elaine Haddock
- Laboratory of Virology, Division of Intramural Research, NIAID, NIH, Hamilton, MT 59840, USA
| | - Friederike Feldmann
- Rocky Mountain Veterinary Branch, Division of Intramural Research, NIAID, NIH, Hamilton, MT 59840, USA
| | - Kimberly Meade-White
- Laboratory of Virology, Division of Intramural Research, NIAID, NIH, Hamilton, MT 59840, USA
| | - Tina Thomas
- Rocky Mountain Veterinary Branch, Division of Intramural Research, NIAID, NIH, Hamilton, MT 59840, USA
| | - Miranda L Hubbard
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kendra L Gully
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Sarah R Leist
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Pablo Hock
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Timothy A Bell
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Gabriela E De la Cruz
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Bentley R Midkiff
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - David R Martinez
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Ginger D Shaw
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Darla R Miller
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Michael J Vernon
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Rachel L Graham
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Dale O Cowley
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA; Animal Models Core Facility, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Stephanie A Montgomery
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Klaus Schughart
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA; Institute of Virology, University of Muenster, 48149 Muenster, Germany
| | - Fernando Pardo Manuel de Villena
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Gregory K Wilkerson
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Martin T Ferris
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Heinz Feldmann
- Laboratory of Virology, Division of Intramural Research, NIAID, NIH, Hamilton, MT 59840, USA
| | - Ralph S Baric
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27599, USA.
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Heine A, Lemmermann NAW, Flores C, Becker-Gotot J, Garbi N, Brossart P, Kurts C. Rapid protection against viral infections by chemokine-accelerated post-exposure vaccination. Front Immunol 2024; 15:1338499. [PMID: 38348028 PMCID: PMC10860197 DOI: 10.3389/fimmu.2024.1338499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 01/09/2024] [Indexed: 02/15/2024] Open
Abstract
Introduction Prophylactic vaccines generate strong and durable immunity to avoid future infections, whereas post-exposure vaccinations are intended to establish rapid protection against already ongoing infections. Antiviral cytotoxic CD8+ T cells (CTL) are activated by dendritic cells (DCs), which themselves must be activated by adjuvants to express costimulatory molecules and so-called signal 0-chemokines that attract naive CTL to the DCs. Hypothesis Here we asked whether a vaccination protocol that combines two adjuvants, a toll-like receptor ligand (TLR) and a natural killer T cell activator, to induce two signal 0 chemokines, synergistically accelerates CTL activation. Methods We used a well-characterized vaccination model based on the model antigen ovalbumin, the TLR9 ligand CpG and the NKT cell ligand α-galactosylceramide to induce signal 0-chemokines. Exploiting this vaccination model, we studied detailed T cell kinetics and T cell profiling in different in vivo mouse models of viral infection. Results We found that CTL induced by both adjuvants obtained a head-start that allowed them to functionally differentiate further and generate higher numbers of protective CTL 1-2 days earlier. Such signal 0-optimized post-exposure vaccination hastened clearance of experimental adenovirus and cytomegalovirus infections. Conclusion Our findings show that signal 0 chemokine-inducing adjuvant combinations gain time in the race against rapidly replicating microbes, which may be especially useful in post-exposure vaccination settings during viral epi/pandemics.
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Affiliation(s)
- Annkristin Heine
- Institute of Experimental Immunology, University of Bonn, Bonn, Germany
- Medical Clinic III, University of Bonn, Bonn, Germany
| | - Niels A. W. Lemmermann
- Institute for Virology and Research Center for Immunotherapy (FZI) at the University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Institute for Virology, University of Bonn, Bonn, Germany
| | - Chrystel Flores
- Institute of Experimental Immunology, University of Bonn, Bonn, Germany
- Medical Clinic III, University of Bonn, Bonn, Germany
| | | | - Natalio Garbi
- Institute of Experimental Immunology, University of Bonn, Bonn, Germany
| | | | - Christian Kurts
- Institute of Experimental Immunology, University of Bonn, Bonn, Germany
- Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
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Martinez-Murillo PA, Huttner A, Lemeille S, Medaglini D, Ottenhoff THM, Harandi AM, Didierlaurent AM, Siegrist CA. Refined innate plasma signature after rVSVΔG-ZEBOV-GP immunization is shared among adult cohorts in Europe and North America. Front Immunol 2024; 14:1279003. [PMID: 38235127 PMCID: PMC10791923 DOI: 10.3389/fimmu.2023.1279003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 12/07/2023] [Indexed: 01/19/2024] Open
Abstract
Background During the last decade Ebola virus has caused several outbreaks in Africa. The recombinant vesicular stomatitis virus-vectored Zaire Ebola (rVSVΔG-ZEBOV-GP) vaccine has proved safe and immunogenic but is reactogenic. We previously identified the first innate plasma signature response after vaccination in Geneva as composed of five monocyte-related biomarkers peaking at day 1 post-immunization that correlates with adverse events, biological outcomes (haematological changes and viremia) and antibody titers. In this follow-up study, we sought to identify additional biomarkers in the same Geneva cohort and validate those identified markers in a US cohort. Methods Additional biomarkers were identified using multiplexed protein biomarker platform O-link and confirmed by Luminex. Principal component analysis (PCA) evaluated if these markers could explain a higher variability of the vaccine response (and thereby refined the initial signature). Multivariable and linear regression models evaluated the correlations of the main components with adverse events, biological outcomes, and antibody titers. External validation of the refined signature was conducted in a second cohort of US vaccinees (n=142). Results Eleven additional biomarkers peaked at day 1 post-immunization: MCP2, MCP3, MCP4, CXCL10, OSM, CX3CL1, MCSF, CXCL11, TRAIL, RANKL and IL15. PCA analysis retained three principal components (PC) that accounted for 79% of the vaccine response variability. PC1 and PC2 were very robust and had different biomarkers that contributed to their variability. PC1 better discriminated different doses, better defined the risk of fever and myalgia, while PC2 better defined the risk of headache. We also found new biomarkers that correlated with reactogenicity, including transient arthritis (MCP-2, CXCL10, CXCL11, CX3CL1, MCSF, IL-15, OSM). Several innate biomarkers are associated with antibody levels one and six months after vaccination. Refined PC1 correlated strongly in both data sets (Geneva: r = 0.97, P < 0.001; US: r = 0.99, P< 0.001). Conclusion Eleven additional biomarkers refined the previously found 5-biomarker Geneva signature. The refined signature better discriminated between different doses, was strongly associated with the risk of adverse events and with antibody responses and was validated in a separate cohort.
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Affiliation(s)
- Paola Andrea Martinez-Murillo
- Center of Vaccinology, Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Angela Huttner
- Center for Vaccinology, Geneva University Hospitals, Geneva, Switzerland
- Division of Infectious Diseases, Geneva University Hospitals, Geneva, Switzerland
- Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Center for Clinical Research, Geneva University Hospitals, Geneva, Switzerland
| | - Sylvain Lemeille
- Center of Vaccinology, Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Donata Medaglini
- Laboratory of Molecular Microbiology and Biotechnology, Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Tom H. M. Ottenhoff
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | - Ali M. Harandi
- Department of Microbiology and Immunology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Vaccine Evaluation Centre, BC Children’s Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Arnaud M. Didierlaurent
- Center of Vaccinology, Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Claire-Anne Siegrist
- Center of Vaccinology, Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Center for Vaccinology, Geneva University Hospitals, Geneva, Switzerland
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Guttieres D, Diepvens C, Decouttere C, Vandaele N. Modeling Supply and Demand Dynamics of Vaccines against Epidemic-Prone Pathogens: Case Study of Ebola Virus Disease. Vaccines (Basel) 2023; 12:24. [PMID: 38250837 PMCID: PMC10819028 DOI: 10.3390/vaccines12010024] [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: 11/10/2023] [Revised: 12/13/2023] [Accepted: 12/22/2023] [Indexed: 01/23/2024] Open
Abstract
Health emergencies caused by epidemic-prone pathogens (EPPs) have increased exponentially in recent decades. Although vaccines have proven beneficial, they are unavailable for many pathogens. Furthermore, achieving timely and equitable access to vaccines against EPPs is not trivial. It requires decision-makers to capture numerous interrelated factors across temporal and spatial scales, with significant uncertainties, variability, delays, and feedback loops that give rise to dynamic and unexpected behavior. Therefore, despite progress in filling R&D gaps, the path to licensure and the long-term viability of vaccines against EPPs continues to be unclear. This paper presents a quantitative system dynamics modeling framework to evaluate the long-term sustainability of vaccine supply under different vaccination strategies. Data from both literature and 50 expert interviews are used to model the supply and demand of a prototypical Ebolavirus Zaire (EBOV) vaccine. Specifically, the case study evaluates dynamics associated with proactive vaccination ahead of an outbreak of similar magnitude as the 2018-2020 epidemic in North Kivu, Democratic Republic of the Congo. The scenarios presented demonstrate how uncertainties (e.g., duration of vaccine-induced protection) and design criteria (e.g., priority geographies and groups, target coverage, frequency of boosters) lead to important tradeoffs across policy aims, public health outcomes, and feasibility (e.g., technical, operational, financial). With sufficient context and data, the framework provides a foundation to apply the model to a broad range of additional geographies and priority pathogens. Furthermore, the ability to identify leverage points for long-term preparedness offers directions for further research.
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Affiliation(s)
- Donovan Guttieres
- Access-to-Medicines Research Centre, Faculty of Economics & Business, KU Leuven, 3000 Leuven, Belgium; (C.D.); (C.D.); (N.V.)
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Igwe I, Onyeneho N, Okeibunor JC, Yao MNK, Diarra T, Djingarey MH, Fall S, Gueye AS. Perceptions and Rumors About the Ebola Virus Disease Vaccine in the Ituri and Kivu Provinces of the Democratic Republic of Congo. JOURNAL OF IMMUNOLOGICAL SCIENCES 2023; Suppl 3:58-68. [PMID: 38333356 PMCID: PMC7615612 DOI: 10.29245/2578-3009/2023/s3.1111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Perceptions and rumors about vaccinations can contribute to vaccine hesitancy. This study aimed to examine perceptions and rumors about the Ebola vaccine during the 10th Ebola Virus Disease outbreak in the Ituri and North Kivu provinces of the Democratic Republic of Congo. Eight hundred randomly selected respondents were surveyed with a uniform structured questionnaire. Further, we collected qualitative data through focus group discussions and using in-depth interview guides. Results revealed several misperceptions and rumors about the vaccine, which led to some level of vaccine hesitancy and refusal among the people. The acceptance rate of the vaccine was 67.3% (below the 80% threshold needed to create herd immunity in the population). More of the urban population (31.3%) than the rural population (10.4%) accepted the vaccine. Refusals were largely due to fear that the vaccine could activate other diseases in the body and could even kill. Some feared that it was a conspiracy of the government to reduce the population in the study area through forced fertility control and death, among other such concerns. In conclusion, these rumors increased mistrust, which challenged the efforts of the government and its partners to safeguard the health of the people.
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Bisanzio D, Davis AE, Talbird SE, Van Effelterre T, Metz L, Gaudig M, Mathieu VO, Brogan AJ. Targeted preventive vaccination campaigns to reduce Ebola outbreaks: An individual-based modeling study. Vaccine 2023; 41:684-693. [PMID: 36526505 DOI: 10.1016/j.vaccine.2022.11.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Nonpharmaceutical interventions (NPI) and ring vaccination (i.e., vaccination that primarily targets contacts and contacts of contacts of Ebola cases) are currently used to reduce the spread of Ebola during outbreaks. Because these measures are typically initiated after an outbreak is declared, they are limited by real-time implementation challenges. Preventive vaccination may provide a complementary option to help protect communities against unpredictable outbreaks. This study aimed to assess the impact of preventive vaccination strategies when implemented in conjunction with NPI and ring vaccination. METHODS A spatial-explicit, individual-based model (IBM) that accounts for heterogeneity of human contact, human movement, and timing of interventions was built to represent Ebola transmission in the Democratic Republic of the Congo. Simulated preventive vaccination strategies targeted healthcare workers (HCW), frontline workers (FW), and the general population (GP) with varying levels of coverage (lower coverage: 30% of HCW/FW, 5% of GP; higher coverage: 60% of HCW/FW, 10% of GP) and efficacy (lower efficacy: 60%; higher efficacy: 90%). RESULTS The IBM estimated that the addition of preventive vaccination for HCW reduced cases, hospitalizations, and deaths by ∼11 % to ∼25 % compared with NPI + ring vaccination alone. Including HCW and FW in the preventive vaccination campaign yielded ∼14 % to ∼38 % improvements in epidemic outcomes. Further including the GP yielded the greatest improvements, with ∼21 % to ∼52 % reductions in epidemic outcomes compared with NPI + ring vaccination alone. In a scenario without ring vaccination, preventive vaccination reduced cases, hospitalizations, and deaths by ∼28 % to ∼59 % compared with NPI alone. In all scenarios, preventive vaccination reduced Ebola transmission particularly during the initial phases of the epidemic, resulting in flatter epidemic curves. CONCLUSIONS The IBM showed that preventive vaccination may reduce Ebola cases, hospitalizations, and deaths, thus safeguarding the healthcare system and providing more time to implement additional interventions during an outbreak.
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Affiliation(s)
- Donal Bisanzio
- RTI International, 701 13th St NW #750, Washington, DC 20005, USA
| | - Ashley E Davis
- RTI Health Solutions, 3040 East Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - Sandra E Talbird
- RTI Health Solutions, 3040 East Cornwallis Road, Research Triangle Park, NC 27709, USA
| | | | - Laurent Metz
- Johnson & Johnson Global Public Health, One Johnson and Johnson Plaza, New Brunswick, NJ 08901, USA
| | - Maren Gaudig
- Johnson & Johnson Global Public Health, One Johnson and Johnson Plaza, New Brunswick, NJ 08901, USA
| | | | - Anita J Brogan
- RTI Health Solutions, 3040 East Cornwallis Road, Research Triangle Park, NC 27709, USA.
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Baiden F, Fleck S, Leigh B, Ayieko P, Tindanbil D, Otieno T, Lawal B, Tehtor M, Rogers M, Odeny L, Hodges MH, Sonnie M, Samai M, Ishola D, Lowe B, Watson-Jones D, Greenwood B. Prevalence of malaria and helminth infections in rural communities in northern Sierra Leone, a baseline study to inform Ebola vaccine study protocols. PLoS One 2022; 17:e0270968. [PMID: 35793331 PMCID: PMC9258822 DOI: 10.1371/journal.pone.0270968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 06/21/2022] [Indexed: 11/18/2022] Open
Abstract
Introduction
Recurrent parasitic infections may influence the immune response to vaccines. In the Partnership for Research on Ebola VACcinations extended follow-UP and clinical research capacity build-UP (PREVAC-UP) study being undertaken in Mambolo, northern Sierra Leone, participants are being followed up to assess the potential impact of exposure to malaria and/or helminth infections on long-term immune response to two Ebola vaccines. To support the development of the assays that will be used in this evaluation, a parasitological survey was conducted in Mambolo between November 2019 and February 2020.
Methods
Healthy individuals aged ≥1 year who were resident in Mambolo Chiefdom were selected using a stratified sampling approach and questionnaires were administered to explore their sociodemographic characteristics. Microscopy was used to detect malaria parasites, intestinal helminths and urinary schistosome infections. Rapid blood tests were used to detect infections with Onchocerca volvulus and Wuchereria bancrofti. We estimated the overall prevalence of these infections and used adjusted logistic regression models to explore risk factors for malaria and hookworm infection.
Results
Eight hundred and fifteen (815) residents, 50.9% of whom were female were surveyed. Overall, 309 (39.1%) of 791 persons tested for malaria had a positive blood slide; Plasmodium falciparum was the dominant species. Helminth infection was detected in 122 (15.0%) of 815 stool samples including three mixed infections. The helminth infections comprised 102 (12.5%) cases of hookworm, 11 (1.3%) cases of Trichuris trichiura, 10 (1.2%) cases of Schistosoma mansoni and two (0.2%) cases of Ascaris lumbricoides. Being male (OR = 2.01, 95% CI 1.15–3.50) and residing in a non-riverine community (OR = 4.02, 95%CI 2.32–6.98) were the factors associated with hookworm infection. Onchocerca volvulus and Wuchereria bancrofti infections were found in 3.3% and 0.4% of participants respectively.
Conclusion
Malaria and hookworm are the most prevalent parasite infections and those most likely to influence long-term immune response to Ebola vaccines among the trial participants.
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Affiliation(s)
- Frank Baiden
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Suzanne Fleck
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Bailah Leigh
- College of Medicine and Allied Health Sciences, University of Sierra Leone, Freetown, Sierra Leone
| | - Philip Ayieko
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
| | - Daniel Tindanbil
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Tuda Otieno
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Bolarinde Lawal
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Mattu Tehtor
- College of Medicine and Allied Health Sciences, University of Sierra Leone, Freetown, Sierra Leone
| | - Maariam Rogers
- College of Medicine and Allied Health Sciences, University of Sierra Leone, Freetown, Sierra Leone
| | - Lazarus Odeny
- Kenya Medical Research Institute, Centre for Respiratory Diseases Research, Nairobi, Kenya
| | | | | | - Mohamed Samai
- College of Medicine and Allied Health Sciences, University of Sierra Leone, Freetown, Sierra Leone
| | - David Ishola
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Brett Lowe
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Deborah Watson-Jones
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
| | - Brian Greenwood
- London School of Hygiene & Tropical Medicine, London, United Kingdom
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11
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Lerch A, Ten Bosch QA, L'Azou Jackson M, Bettis AA, Bernuzzi M, Murphy GAV, Tran QM, Huber JH, Siraj AS, Bron GM, Elliott M, Hartlage CS, Koh S, Strimbu K, Walters M, Perkins TA, Moore SM. Projecting vaccine demand and impact for emerging zoonotic pathogens. BMC Med 2022; 20:202. [PMID: 35705986 PMCID: PMC9200440 DOI: 10.1186/s12916-022-02405-1] [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: 01/12/2022] [Accepted: 05/14/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Despite large outbreaks in humans seeming improbable for a number of zoonotic pathogens, several pose a concern due to their epidemiological characteristics and evolutionary potential. To enable effective responses to these pathogens in the event that they undergo future emergence, the Coalition for Epidemic Preparedness Innovations is advancing the development of vaccines for several pathogens prioritized by the World Health Organization. A major challenge in this pursuit is anticipating demand for a vaccine stockpile to support outbreak response. METHODS We developed a modeling framework for outbreak response for emerging zoonoses under three reactive vaccination strategies to assess sustainable vaccine manufacturing needs, vaccine stockpile requirements, and the potential impact of the outbreak response. This framework incorporates geographically variable zoonotic spillover rates, human-to-human transmission, and the implementation of reactive vaccination campaigns in response to disease outbreaks. As proof of concept, we applied the framework to four priority pathogens: Lassa virus, Nipah virus, MERS coronavirus, and Rift Valley virus. RESULTS Annual vaccine regimen requirements for a population-wide strategy ranged from > 670,000 (95% prediction interval 0-3,630,000) regimens for Lassa virus to 1,190,000 (95% PrI 0-8,480,000) regimens for Rift Valley fever virus, while the regimens required for ring vaccination or targeting healthcare workers (HCWs) were several orders of magnitude lower (between 1/25 and 1/700) than those required by a population-wide strategy. For each pathogen and vaccination strategy, reactive vaccination typically prevented fewer than 10% of cases, because of their presently low R0 values. Targeting HCWs had a higher per-regimen impact than population-wide vaccination. CONCLUSIONS Our framework provides a flexible methodology for estimating vaccine stockpile needs and the geographic distribution of demand under a range of outbreak response scenarios. Uncertainties in our model estimates highlight several knowledge gaps that need to be addressed to target vulnerable populations more accurately. These include surveillance gaps that mask the true geographic distribution of each pathogen, details of key routes of spillover from animal reservoirs to humans, and the role of human-to-human transmission outside of healthcare settings. In addition, our estimates are based on the current epidemiology of each pathogen, but pathogen evolution could alter vaccine stockpile requirements.
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Affiliation(s)
- Anita Lerch
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Quirine A Ten Bosch
- Quantitative Veterinary Epidemiology, Wageningen University and Research, Wageningen, The Netherlands
| | | | - Alison A Bettis
- Coalition for Epidemic Preparedness Innovations (CEPI), Oslo, Norway
| | - Mauro Bernuzzi
- Coalition for Epidemic Preparedness Innovations (CEPI), London, UK
| | | | - Quan M Tran
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - John H Huber
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Amir S Siraj
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Gebbiena M Bron
- Quantitative Veterinary Epidemiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Margaret Elliott
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Carson S Hartlage
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Sojung Koh
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Kathyrn Strimbu
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Magdalene Walters
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - T Alex Perkins
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA.
| | - Sean M Moore
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA.
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12
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Genisca AE, Chu TC, Huang L, Gainey M, Adeniji M, Mbong EN, Kennedy SB, Laghari R, Nganga F, Muhayangabo RF, Vaishnav H, Perera SM, Colubri A, Levine AC, Michelow IC. Risk Prediction Score for Pediatric Patients with Suspected Ebola Virus Disease. Emerg Infect Dis 2022; 28:1189-1197. [PMID: 35608611 PMCID: PMC9155869 DOI: 10.3201/eid2806.212265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Rapid diagnostic tools for children with Ebola virus disease (EVD) are needed to expedite isolation and treatment. To evaluate a predictive diagnostic tool, we examined retrospective data (2014-2015) from the International Medical Corps Ebola Treatment Centers in West Africa. We incorporated statistically derived candidate predictors into a 7-point Pediatric Ebola Risk Score. Evidence of bleeding or having known or no known Ebola contacts was positively associated with an EVD diagnosis, whereas abdominal pain was negatively associated. Model discrimination using area under the curve (AUC) was 0.87, which outperforms the World Health Organization criteria (AUC 0.56). External validation, performed by using data from International Medical Corps Ebola Treatment Centers in the Democratic Republic of the Congo during 2018-2019, showed an AUC of 0.70. External validation showed that discrimination achieved by using World Health Organization criteria was similar; however, the Pediatric Ebola Risk Score is simpler to use.
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Affiliation(s)
| | | | - Lawrence Huang
- Brown Emergency Medicine, Providence, Rhode Island, USA (A.E. Genisca, H. Vaishnav, A.C. Levine)
- Alpert Medical School of Brown University, Providence (A.E. Genisca, A.C. Levine, I.C. Michelow)
- University of Georgia, Athens, Georgia, USA (T.C. Chu)
- Brown University, Providence (L. Huang, M. Adeniji)
- Rhode Island Hospital, Providence (M. Gainey)
- International Medical Corps, Goma, Democratic Republic of the Congo (E.N. Mbong, R. Laghari, F. Nganga, R.F. Muhayangabo)
- Ministry of Health, Monrovia, Liberia (S.B. Kennedy)
- International Medical Corps, Washington, DC, USA (S.M. Perera)
- University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA (A. Colubri)
| | - Monique Gainey
- Brown Emergency Medicine, Providence, Rhode Island, USA (A.E. Genisca, H. Vaishnav, A.C. Levine)
- Alpert Medical School of Brown University, Providence (A.E. Genisca, A.C. Levine, I.C. Michelow)
- University of Georgia, Athens, Georgia, USA (T.C. Chu)
- Brown University, Providence (L. Huang, M. Adeniji)
- Rhode Island Hospital, Providence (M. Gainey)
- International Medical Corps, Goma, Democratic Republic of the Congo (E.N. Mbong, R. Laghari, F. Nganga, R.F. Muhayangabo)
- Ministry of Health, Monrovia, Liberia (S.B. Kennedy)
- International Medical Corps, Washington, DC, USA (S.M. Perera)
- University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA (A. Colubri)
| | - Moyinoluwa Adeniji
- Brown Emergency Medicine, Providence, Rhode Island, USA (A.E. Genisca, H. Vaishnav, A.C. Levine)
- Alpert Medical School of Brown University, Providence (A.E. Genisca, A.C. Levine, I.C. Michelow)
- University of Georgia, Athens, Georgia, USA (T.C. Chu)
- Brown University, Providence (L. Huang, M. Adeniji)
- Rhode Island Hospital, Providence (M. Gainey)
- International Medical Corps, Goma, Democratic Republic of the Congo (E.N. Mbong, R. Laghari, F. Nganga, R.F. Muhayangabo)
- Ministry of Health, Monrovia, Liberia (S.B. Kennedy)
- International Medical Corps, Washington, DC, USA (S.M. Perera)
- University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA (A. Colubri)
| | - Eta N. Mbong
- Brown Emergency Medicine, Providence, Rhode Island, USA (A.E. Genisca, H. Vaishnav, A.C. Levine)
- Alpert Medical School of Brown University, Providence (A.E. Genisca, A.C. Levine, I.C. Michelow)
- University of Georgia, Athens, Georgia, USA (T.C. Chu)
- Brown University, Providence (L. Huang, M. Adeniji)
- Rhode Island Hospital, Providence (M. Gainey)
- International Medical Corps, Goma, Democratic Republic of the Congo (E.N. Mbong, R. Laghari, F. Nganga, R.F. Muhayangabo)
- Ministry of Health, Monrovia, Liberia (S.B. Kennedy)
- International Medical Corps, Washington, DC, USA (S.M. Perera)
- University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA (A. Colubri)
| | - Stephen B. Kennedy
- Brown Emergency Medicine, Providence, Rhode Island, USA (A.E. Genisca, H. Vaishnav, A.C. Levine)
- Alpert Medical School of Brown University, Providence (A.E. Genisca, A.C. Levine, I.C. Michelow)
- University of Georgia, Athens, Georgia, USA (T.C. Chu)
- Brown University, Providence (L. Huang, M. Adeniji)
- Rhode Island Hospital, Providence (M. Gainey)
- International Medical Corps, Goma, Democratic Republic of the Congo (E.N. Mbong, R. Laghari, F. Nganga, R.F. Muhayangabo)
- Ministry of Health, Monrovia, Liberia (S.B. Kennedy)
- International Medical Corps, Washington, DC, USA (S.M. Perera)
- University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA (A. Colubri)
| | - Razia Laghari
- Brown Emergency Medicine, Providence, Rhode Island, USA (A.E. Genisca, H. Vaishnav, A.C. Levine)
- Alpert Medical School of Brown University, Providence (A.E. Genisca, A.C. Levine, I.C. Michelow)
- University of Georgia, Athens, Georgia, USA (T.C. Chu)
- Brown University, Providence (L. Huang, M. Adeniji)
- Rhode Island Hospital, Providence (M. Gainey)
- International Medical Corps, Goma, Democratic Republic of the Congo (E.N. Mbong, R. Laghari, F. Nganga, R.F. Muhayangabo)
- Ministry of Health, Monrovia, Liberia (S.B. Kennedy)
- International Medical Corps, Washington, DC, USA (S.M. Perera)
- University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA (A. Colubri)
| | - Fiston Nganga
- Brown Emergency Medicine, Providence, Rhode Island, USA (A.E. Genisca, H. Vaishnav, A.C. Levine)
- Alpert Medical School of Brown University, Providence (A.E. Genisca, A.C. Levine, I.C. Michelow)
- University of Georgia, Athens, Georgia, USA (T.C. Chu)
- Brown University, Providence (L. Huang, M. Adeniji)
- Rhode Island Hospital, Providence (M. Gainey)
- International Medical Corps, Goma, Democratic Republic of the Congo (E.N. Mbong, R. Laghari, F. Nganga, R.F. Muhayangabo)
- Ministry of Health, Monrovia, Liberia (S.B. Kennedy)
- International Medical Corps, Washington, DC, USA (S.M. Perera)
- University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA (A. Colubri)
| | - Rigo F. Muhayangabo
- Brown Emergency Medicine, Providence, Rhode Island, USA (A.E. Genisca, H. Vaishnav, A.C. Levine)
- Alpert Medical School of Brown University, Providence (A.E. Genisca, A.C. Levine, I.C. Michelow)
- University of Georgia, Athens, Georgia, USA (T.C. Chu)
- Brown University, Providence (L. Huang, M. Adeniji)
- Rhode Island Hospital, Providence (M. Gainey)
- International Medical Corps, Goma, Democratic Republic of the Congo (E.N. Mbong, R. Laghari, F. Nganga, R.F. Muhayangabo)
- Ministry of Health, Monrovia, Liberia (S.B. Kennedy)
- International Medical Corps, Washington, DC, USA (S.M. Perera)
- University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA (A. Colubri)
| | - Himanshu Vaishnav
- Brown Emergency Medicine, Providence, Rhode Island, USA (A.E. Genisca, H. Vaishnav, A.C. Levine)
- Alpert Medical School of Brown University, Providence (A.E. Genisca, A.C. Levine, I.C. Michelow)
- University of Georgia, Athens, Georgia, USA (T.C. Chu)
- Brown University, Providence (L. Huang, M. Adeniji)
- Rhode Island Hospital, Providence (M. Gainey)
- International Medical Corps, Goma, Democratic Republic of the Congo (E.N. Mbong, R. Laghari, F. Nganga, R.F. Muhayangabo)
- Ministry of Health, Monrovia, Liberia (S.B. Kennedy)
- International Medical Corps, Washington, DC, USA (S.M. Perera)
- University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA (A. Colubri)
| | - Shiromi M. Perera
- Brown Emergency Medicine, Providence, Rhode Island, USA (A.E. Genisca, H. Vaishnav, A.C. Levine)
- Alpert Medical School of Brown University, Providence (A.E. Genisca, A.C. Levine, I.C. Michelow)
- University of Georgia, Athens, Georgia, USA (T.C. Chu)
- Brown University, Providence (L. Huang, M. Adeniji)
- Rhode Island Hospital, Providence (M. Gainey)
- International Medical Corps, Goma, Democratic Republic of the Congo (E.N. Mbong, R. Laghari, F. Nganga, R.F. Muhayangabo)
- Ministry of Health, Monrovia, Liberia (S.B. Kennedy)
- International Medical Corps, Washington, DC, USA (S.M. Perera)
- University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA (A. Colubri)
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13
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Obeng-Kusi M, Habila MA, Roe DJ, Erstad B, Abraham I. Economic evaluation using dynamic transition modeling of ebola virus vaccination in lower-and-middle-income countries. J Med Econ 2021; 24:1-13. [PMID: 34866541 DOI: 10.1080/13696998.2021.2002092] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND With the increasing occurrence of infectious diseases in lower-and-middle-income countries (LMICs), emergency preparedness is essential for rapid response and mitigation. Economic evaluations of mitigation technologies and strategies have been recommended for inclusion in emergency preparedness plans. We aimed to perform an economic evaluation using dynamic transition modeling of ebola virus disease (EVD) vaccination in a hypothetical community of 1,000 persons in the Democratic Republic of Congo (DRC). METHOD Using a modified SEIR (Susceptible, Exposed, Infectious, Recovered, with Death added [SEIR-D]) model that accounted for death and epidemiological data from an EVD outbreak in the DRC, we modeled the transmission of EVD in a hypothetical population of 1,000. With our model, we estimated the cost-effectiveness of an EVD vaccine and an EVD vaccination intervention. RESULTS The results showed vaccinating 50% of the population at risk prevented 670 cases, 538 deaths, and 22,022 disability-adjusted life years (DALYs). The vaccine was found to be cost-effective with an incremental cost-effectiveness ratio (ICER) of $95.63 per DALY averted. We also determined the minimum required vaccination coverage for cost-effectiveness to be 40%. Sensitivity analysis showed our model to be fairly robust, assuring relatively consistent results even with variations in such input parameters as cost of screening, as well as transmission, infection, incubation, and case fatality rates. CONCLUSION EVD vaccination in our hypothetical population was found to be cost-effective from the payer perspective. Our model presents an efficient and reliable approach for conducting economic evaluations of infectious disease interventions as part of an emergency preparedness plan.
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Affiliation(s)
- Mavis Obeng-Kusi
- Center for Health Outcomes and PharmacoEconomic Research, University of Arizona, Tucson, AZ, USA
| | - Magdiel A Habila
- Center for Health Outcomes and PharmacoEconomic Research, University of Arizona, Tucson, AZ, USA
- Mel & Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - Denise J Roe
- Mel & Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - Brian Erstad
- Pharmacy Practice and Science, University of Arizona, Tucson, AZ, USA
| | - Ivo Abraham
- Center for Health Outcomes and PharmacoEconomic Research, University of Arizona, Tucson, AZ, USA
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14
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Abstract
The significant advances made by the global scientific community during the COVID-19 pandemic, exemplified by the development of multiple SARS-CoV-2 vaccines in less than 1 y, were made possible in part because of animal research. Historically, animals have been used to study the characterization, treatment, and prevention of most of the major infectious disease outbreaks that humans have faced. From the advent of modern 'germ theory' prior to the 1918 Spanish Flu pandemic through the more recent Ebola and Zika virus outbreaks, research that uses animals has revealed or supported key discoveries in disease pathogenesis and therapy development, helping to save lives during crises. Here we summarize the role of animal research in past pandemic and epidemic response efforts, as well as current and future considerations for animal research in the context of infectious disease research.
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Affiliation(s)
- Jacqueline K Brockhurst
- Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jason S Villano
- Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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15
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Meredith HR, Giles JR, Perez-Saez J, Mande T, Rinaldo A, Mutembo S, Kabalo EN, Makungo K, Buckee CO, Tatem AJ, Metcalf CJE, Wesolowski A. Characterizing human mobility patterns in rural settings of sub-Saharan Africa. eLife 2021; 10:e68441. [PMID: 34533456 PMCID: PMC8448534 DOI: 10.7554/elife.68441] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 08/21/2021] [Indexed: 11/27/2022] Open
Abstract
Human mobility is a core component of human behavior and its quantification is critical for understanding its impact on infectious disease transmission, traffic forecasting, access to resources and care, intervention strategies, and migratory flows. When mobility data are limited, spatial interaction models have been widely used to estimate human travel, but have not been extensively validated in low- and middle-income settings. Geographic, sociodemographic, and infrastructure differences may impact the ability for models to capture these patterns, particularly in rural settings. Here, we analyzed mobility patterns inferred from mobile phone data in four Sub-Saharan African countries to investigate the ability for variants on gravity and radiation models to estimate travel. Adjusting the gravity model such that parameters were fit to different trip types, including travel between more or less populated areas and/or different regions, improved model fit in all four countries. This suggests that alternative models may be more useful in these settings and better able to capture the range of mobility patterns observed.
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Affiliation(s)
- Hannah R Meredith
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States
| | - John R Giles
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States
| | - Javier Perez-Saez
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States
| | - Théophile Mande
- Bureau d'Etudes Scientifiques et Techniques - Eau, Energie, Environnement (BEST-3E), Ouagadougou, Burkina Faso
| | - Andrea Rinaldo
- Dipartimento di Ingegneria Civile Edile ed Ambientale, Università di Padova, Padova, Italy
- Laboratory of Ecohydrology, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Simon Mutembo
- Department of International Health, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States
- Macha Research Trust, Choma, Zambia
| | - Elliot N Kabalo
- Zambia Information and Communications Technology Authority, Lusaka, Zambia
| | | | - Caroline O Buckee
- Department of Epidemiology and the Center for Communicable Disease Dynamics, Harvard TH Chan School of Public Health, Boston, United States
| | - Andrew J Tatem
- WorldPop, School of Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - C Jessica E Metcalf
- Department of Ecology and Evolutionary Biology and the Princeton School of Public and International Affairs, Princeton University, Princeton, United States
| | - Amy Wesolowski
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States
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16
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Liu G, Cao W, Salawudeen A, Zhu W, Emeterio K, Safronetz D, Banadyga L. Vesicular Stomatitis Virus: From Agricultural Pathogen to Vaccine Vector. Pathogens 2021; 10:1092. [PMID: 34578125 PMCID: PMC8470541 DOI: 10.3390/pathogens10091092] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 11/16/2022] Open
Abstract
Vesicular stomatitis virus (VSV), which belongs to the Vesiculovirus genus of the family Rhabdoviridae, is a well studied livestock pathogen and prototypic non-segmented, negative-sense RNA virus. Although VSV is responsible for causing economically significant outbreaks of vesicular stomatitis in cattle, horses, and swine, the virus also represents a valuable research tool for molecular biologists and virologists. Indeed, the establishment of a reverse genetics system for the recovery of infectious VSV from cDNA transformed the utility of this virus and paved the way for its use as a vaccine vector. A highly effective VSV-based vaccine against Ebola virus recently received clinical approval, and many other VSV-based vaccines have been developed, particularly for high-consequence viruses. This review seeks to provide a holistic but concise overview of VSV, covering the virus's ascension from perennial agricultural scourge to promising medical countermeasure, with a particular focus on vaccines.
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Affiliation(s)
- Guodong Liu
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada
| | - Wenguang Cao
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada
| | - Abdjeleel Salawudeen
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Wenjun Zhu
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3M4, Canada
| | - Karla Emeterio
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - David Safronetz
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Logan Banadyga
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada
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17
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Levine MM, Abdullah S, Arabi YM, Darko DM, Durbin AP, Estrada V, Jamrozik E, Kremsner PG, Lagos R, Pitisuttithum P, Plotkin SA, Sauerwein R, Shi SL, Sommerfelt H, Subbarao K, Treanor JJ, Vrati S, King D, Balasingam S, Weller C, Aguilar AO, Cassetti MC, Krause PR, Restrepo AMH. Viewpoint of a WHO Advisory Group Tasked to Consider Establishing a Closely-monitored Challenge Model of Coronavirus Disease 2019 (COVID-19) in Healthy Volunteers. Clin Infect Dis 2021; 72:2035-2041. [PMID: 32857836 PMCID: PMC7499532 DOI: 10.1093/cid/ciaa1290] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Indexed: 12/16/2022] Open
Abstract
WHO convened an Advisory Group (AG) to consider the feasibility, potential value, and limitations of establishing a closely-monitored challenge model of experimental severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) in healthy adult volunteers. The AG included experts in design, establishment, and performance of challenges. This report summarizes issues that render a COVID-19 model daunting to establish (the potential of SARS-CoV-2 to cause severe/fatal illness, its high transmissibility, and lack of a "rescue treatment" to prevent progression from mild/moderate to severe clinical illness) and it proffers prudent strategies for stepwise model development, challenge virus selection, guidelines for manufacturing challenge doses, and ways to contain SARS-CoV-2 and prevent transmission to household/community contacts. A COVID-19 model could demonstrate protection against virus shedding and/or illness induced by prior SARS-CoV-2 challenge or vaccination. A limitation of the model is that vaccine efficacy in experimentally challenged healthy young adults cannot per se be extrapolated to predict efficacy in elderly/high-risk adults.
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Affiliation(s)
- Myron M Levine
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | - Yaseen M Arabi
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center, Riyadh, Kingdom of Saudi Arabia
| | | | - Anna P Durbin
- Department of International Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Vicente Estrada
- Medical School, Complutense University, Hospital Clínico San Carlos, Madrid, Spain
| | | | - Peter G Kremsner
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné, Gabon
| | - Rosanna Lagos
- Centro para Vacunas en Desarrollo (CVD-Chile), Santiago, Chile
| | - Punnee Pitisuttithum
- Vaccine Trial Centre, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Stanley A Plotkin
- Department of Pediatrics, University of Pennsylvania, Doylestown, Pennsylvania, USA
| | - Robert Sauerwein
- Medical Parasitology Department, Radboud University, Nijmegen, The Netherlands
| | - Sheng-Li Shi
- Center for Emerging Infectious Diseases, Wuhan Institute of Virology, Wuhan, China
| | - Halvor Sommerfelt
- Centre for Intervention Science in Maternal and Child Health, Department of Global Public Health and Primary Care, University of Bergen, Bergen, and Norwegian Institute of Public Health, Oslo, Norway
| | - Kanta Subbarao
- WHO Collaborating Centre for Reference and Research on Influenza and Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute, Melbourne, Australia
| | - John J Treanor
- Infectious Diseases Division, University of Rochester Medical Center, Rochester, New York, USA
| | - Sudhanshu Vrati
- Regional Centre for Biotechnology, Haryana (NCR Delhi), India
| | - Deborah King
- Vaccines Priority Area, Wellcome Trust, London, United Kingdom
| | | | - Charlie Weller
- Vaccines Programme, Wellcome Trust, London, United Kingdom
| | - Anastazia Older Aguilar
- Global Health Discovery & Translational Sciences, Bill & Melinda Gates Foundation, Seattle, Washington, USA
| | - M Cristina Cassetti
- Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, USA
| | - Philip R Krause
- Office of Vaccines Research and Review, CEBR, FDA, Silver Spring, Maryland, USA.,Chair, WHO R&D Blueprint COVID-19 Vaccines Working Group
| | - Ana Maria Henao Restrepo
- Office of the Executive Director (WHE), WHO Health Emergencies Programme, World Health Organization, Geneva, Switzerland
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18
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Abstract
In the recent years, Ebola virus has been responsible for several major epidemics. Research efforts have allowed the development and evaluation in the field of several vaccine candidates. At present, two of them are already approved and used in the fight against the virus in the Democratic Republic of Congo. This review aims to describe the different candidates, the clinical trials that have been conducted as well as the first results in the field.
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Affiliation(s)
- Baptiste Martin
- CIRI, Centre international de recherche en infectiologie, équipe Bases moléculaires de la pathogénicité virale, Univ Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Viktor Volchkov
- CIRI, Centre international de recherche en infectiologie, équipe Bases moléculaires de la pathogénicité virale, Univ Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Olivier Reynard
- CIRI, Centre international de recherche en infectiologie, équipe Bases moléculaires de la pathogénicité virale, Univ Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007, Lyon, France
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19
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Mummah RO, Hoff NA, Rimoin AW, Lloyd-Smith JO. Controlling emerging zoonoses at the animal-human interface. ONE HEALTH OUTLOOK 2020; 2:17. [PMID: 33073176 PMCID: PMC7550773 DOI: 10.1186/s42522-020-00024-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 07/09/2020] [Indexed: 05/21/2023]
Abstract
BACKGROUND For many emerging or re-emerging pathogens, cases in humans arise from a mixture of introductions (via zoonotic spillover from animal reservoirs or geographic spillover from endemic regions) and secondary human-to-human transmission. Interventions aiming to reduce incidence of these infections can be focused on preventing spillover or reducing human-to-human transmission, or sometimes both at once, and typically are governed by resource constraints that require policymakers to make choices. Despite increasing emphasis on using mathematical models to inform disease control policies, little attention has been paid to guiding rational disease control at the animal-human interface. METHODS We introduce a modeling framework to analyze the impacts of different disease control policies, focusing on pathogens exhibiting subcritical transmission among humans (i.e. pathogens that cannot establish sustained human-to-human transmission). We quantify the relative effectiveness of measures to reduce spillover (e.g. reducing contact with animal hosts), human-to-human transmission (e.g. case isolation), or both at once (e.g. vaccination), across a range of epidemiological contexts. RESULTS We provide guidelines for choosing which mode of control to prioritize in different epidemiological scenarios and considering different levels of resource and relative costs. We contextualize our analysis with current zoonotic pathogens and other subcritical pathogens, such as post-elimination measles, and control policies that have been applied. CONCLUSIONS Our work provides a model-based, theoretical foundation to understand and guide policy for subcritical zoonoses, integrating across disciplinary and species boundaries in a manner consistent with One Health principles.
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Affiliation(s)
- Riley O. Mummah
- Department of Ecology and Evolutionary Biology, University of California, 610 Charles E Young Dr S, Los Angeles, CA 90095 USA
- Department of Epidemiology, University of California, Los Angeles, CA 90095 USA
| | - Nicole A. Hoff
- Department of Epidemiology, University of California, Los Angeles, CA 90095 USA
| | - Anne W. Rimoin
- Department of Epidemiology, University of California, Los Angeles, CA 90095 USA
| | - James O. Lloyd-Smith
- Department of Ecology and Evolutionary Biology, University of California, 610 Charles E Young Dr S, Los Angeles, CA 90095 USA
- Fogarty International Center, National Institutes of Health, Bethesda, MD 20892 USA
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20
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Toniolo SP, Afkhami S, D'Agostino MR, Lichty BD, Cranston ED, Xing Z, Thompson MR. Spray dried VSV-vectored vaccine is thermally stable and immunologically active in vivo. Sci Rep 2020; 10:13349. [PMID: 32770018 PMCID: PMC7414861 DOI: 10.1038/s41598-020-70325-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 06/15/2020] [Indexed: 12/12/2022] Open
Abstract
Effective vaccine delivery and coverage to rural and resource-poor countries is hindered by the dependence on cold chain storage. As such, developments of cold chain-free technologies are highly sought. Although spray dried adenoviral vectors have shown long term stability at ambient temperatures and relatively low humidity, it remains to be determined whether similar excipient formulations are applicable to other viral vectors. To address this, we have spray dried vesicular stomatitis virus (VSV)-vectors with a panel of well-characterized sugar excipients to determine the optimal formulation for vector stabilization. Upon reconstitution, we show that trehalose conferred superior stability of VSV both in vitro and in vivo. Importantly, following cold chain-free storage at elevated temperatures at 37 °C for 15 days, we show that a VSV-vectored vaccine retains its in vivo immunogenicity, whereas a liquid control completely lost its immune-stimulating ability. Our results provide foundational evidence that spray drying with properly tested excipients can stabilize viral vectors such as VSV, allowing them to be stored long-term at elevated temperatures without dependency on cold chain conditions.
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Affiliation(s)
- Steven P Toniolo
- Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada
| | - Sam Afkhami
- McMaster Immunology Research Center, McMaster University, Hamilton, ON, Canada.,Department of Pathology & Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Michael R D'Agostino
- McMaster Immunology Research Center, McMaster University, Hamilton, ON, Canada.,Department of Pathology & Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Brian D Lichty
- McMaster Immunology Research Center, McMaster University, Hamilton, ON, Canada.,Department of Pathology & Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Emily D Cranston
- Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada.,Department of Wood Science, The University of British Columbia, Vancouver, Canada.,Department of Chemical and Biological Engineering, The University of British Columbia, Vancouver, Canada
| | - Zhou Xing
- McMaster Immunology Research Center, McMaster University, Hamilton, ON, Canada.,Department of Pathology & Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Michael R Thompson
- Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada.
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21
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Espinoza B, Castillo-Chavez C, Perrings C. Mobility restrictions for the control of epidemics: When do they work? PLoS One 2020; 15:e0235731. [PMID: 32628716 PMCID: PMC7337314 DOI: 10.1371/journal.pone.0235731] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/22/2020] [Indexed: 11/18/2022] Open
Abstract
Background Mobility restrictions—trade and travel bans, border closures and, in extreme cases, area quarantines or cordons sanitaires—are among the most widely used measures to control infectious diseases. Restrictions of this kind were important in the response to epidemics of SARS (2003), H1N1 influenza (2009), Ebola (2014) and, currently in the containment of the ongoing COVID-19 pandemic. However, they do not always work as expected. Methods To determine when mobility restrictions reduce the size of an epidemic, we use a model of disease transmission within and between economically heterogeneous locally connected communities. One community comprises a low-risk, low-density population with access to effective medical resources. The other comprises a high-risk, high-density population without access to effective medical resources. Findings Unrestricted mobility between the two risk communities increases the number of secondary cases in the low-risk community but reduces the overall epidemic size. By contrast, the imposition of a cordon sanitaire around the high-risk community reduces the number of secondary infections in the low-risk community but increases the overall epidemic size. Interpretation Mobility restrictions may not be an effective policy for controlling the spread of an infectious disease if it is assessed by the overall final epidemic size. Patterns of mobility established through the independent mobility and trade decisions of people in both communities may be sufficient to contain epidemics.
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Affiliation(s)
- Baltazar Espinoza
- Simon A. Levin Mathematical and Computational Modeling Sciences Center, Arizona State University, Tempe, Arizona, United States of America
- * E-mail:
| | | | - Charles Perrings
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
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22
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The C-Terminal Domain of the Sudan Ebolavirus L Protein Is Essential for RNA Binding and Methylation. J Virol 2020; 94:JVI.00520-20. [PMID: 32269120 DOI: 10.1128/jvi.00520-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 03/29/2020] [Indexed: 12/20/2022] Open
Abstract
The large (L) protein of Ebola virus is a key protein for virus replication. Its N-terminal region harbors the RNA-dependent RNA polymerase activity, and its C terminus contains a cap assembling line composed of a capping domain and a methyltransferase domain (MTase) followed by a C-terminal domain (CTD) of unknown function. The L protein MTase catalyzes methylation at the 2'-O and N-7 positions of the cap structures. In addition, the MTase of Ebola virus can induce cap-independent internal adenosine 2'-O-methylation. In this work, we investigated the CTD role in the regulation of the cap-dependent and cap-independent MTase activities of the L protein. We found that the CTD, which is enriched in basic amino acids, plays a key role in RNA binding and in turn regulates the different MTase activities. We demonstrated that the mutation of CTD residues modulates specifically the different MTase activities. Altogether, our results highlight the pivotal role of the L protein CTD in the control of viral RNA methylation, which is critical for Ebola virus replication and escape from the innate response in infected cells.IMPORTANCE Ebola virus infects human and nonhuman primates, causing severe infections that are often fatal. The epidemics, in West and Central Africa, emphasize the urgent need to develop antiviral therapies. The Ebola virus large protein (L), which is the central protein for viral RNA replication/transcription, harbors a methyltransferase domain followed by a C-terminal domain of unknown function. We show that the C-terminal domain regulates the L protein methyltransferase activities and consequently participates in viral replication and escape of the host innate immunity.
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23
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Tapia MD, Doumbia M, Dembele R, Ball K, N'Diaye B, Amadou H, Charara S, Henao-Restrepo AM, Merle CS, Sow SO, Levine MM. Arranging good clinical practices training and trial monitoring for a vaccine efficacy study during a public health emergency of international concern. Vaccine 2020; 38:4050-4056. [DOI: 10.1016/j.vaccine.2020.03.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 02/28/2020] [Accepted: 03/02/2020] [Indexed: 11/17/2022]
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24
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Impact of prophylactic vaccination strategies on Ebola virus transmission: A modeling analysis. PLoS One 2020; 15:e0230406. [PMID: 32339195 PMCID: PMC7185698 DOI: 10.1371/journal.pone.0230406] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 03/01/2020] [Indexed: 01/18/2023] Open
Abstract
Ebola epidemics constitute serious public health emergencies. Multiple vaccines are under development to prevent these epidemics and avoid the associated morbidity and mortality. Assessing the potential impact of these vaccines on morbidity and mortality of Ebola is essential for devising prevention strategies. A mean-field compartmental stochastic model was developed for this purpose and validated by simulating the 2014 Sierra Leone epidemic. We assessed the impacts of prophylactic vaccination of healthcare workers (HCW) both alone and in combination with the vaccination of the general population (entire susceptible population other than HCW). The model simulated 8,706 (95% confidence intervals [CI]: 478–21,942) cases and 3,575 (95%CI: 179–9,031) deaths in Sierra Leone, in line with WHO-reported statistics for the 2014 epidemic (8,704 cases and 3,587 deaths). Relative to this base case, the model then estimated that prophylactic vaccination of only 10% of HCW will avert 12% (95% CI: 6%-14%) of overall cases and deaths, while vaccination of 30% of HCW will avert 34% of overall cases (95% CI: 30%-64%) and deaths (95% CI: 30%-65%). Prophylactic vaccination of 1% and 5% of the general population in addition to vaccinating 30% of HCW was estimated to result in reduction in cases by 44% (95% CI: 39%-61%) and 72% (95% CI: 68%-84%) respectively, and deaths by 45% (95% CI: 40%-61%) and 74% (95% CI: 70%-85%) respectively. Prophylactic vaccination of even small proportions of HCW is estimated to significantly reduce incidence of Ebola and associated mortality. The effect is greatly enhanced by the additional vaccination even of small percentages of the general population. These findings could be used to inform the planning of prevention strategies.
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25
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Jacob ST, Crozier I, Fischer WA, Hewlett A, Kraft CS, Vega MADL, Soka MJ, Wahl V, Griffiths A, Bollinger L, Kuhn JH. Ebola virus disease. Nat Rev Dis Primers 2020; 6:13. [PMID: 32080199 PMCID: PMC7223853 DOI: 10.1038/s41572-020-0147-3] [Citation(s) in RCA: 296] [Impact Index Per Article: 74.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/10/2020] [Indexed: 12/16/2022]
Abstract
Ebola virus disease (EVD) is a severe and frequently lethal disease caused by Ebola virus (EBOV). EVD outbreaks typically start from a single case of probable zoonotic transmission, followed by human-to-human transmission via direct contact or contact with infected bodily fluids or contaminated fomites. EVD has a high case-fatality rate; it is characterized by fever, gastrointestinal signs and multiple organ dysfunction syndrome. Diagnosis requires a combination of case definition and laboratory tests, typically real-time reverse transcription PCR to detect viral RNA or rapid diagnostic tests based on immunoassays to detect EBOV antigens. Recent advances in medical countermeasure research resulted in the recent approval of an EBOV-targeted vaccine by European and US regulatory agencies. The results of a randomized clinical trial of investigational therapeutics for EVD demonstrated survival benefits from two monoclonal antibody products targeting the EBOV membrane glycoprotein. New observations emerging from the unprecedented 2013-2016 Western African EVD outbreak (the largest in history) and the ongoing EVD outbreak in the Democratic Republic of the Congo have substantially improved the understanding of EVD and viral persistence in survivors of EVD, resulting in new strategies toward prevention of infection and optimization of clinical management, acute illness outcomes and attendance to the clinical care needs of patients.
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Affiliation(s)
- Shevin T Jacob
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
- Global Health Security Department, Infectious Diseases Institute, Makerere University, Kampala, Uganda
| | - Ian Crozier
- Integrated Research Facility at Fort Detrick, Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research supported by the National Cancer Institute, Frederick, MD, USA
| | - William A Fischer
- Department of Medicine, Division of Pulmonary Disease and Critical Care Medicine, Chapel Hill, NC, USA
| | - Angela Hewlett
- Nebraska Biocontainment Unit, Division of Infectious Diseases, University of Nebraska Medical Center, Omaha, NE, USA
| | - Colleen S Kraft
- Microbiology Section, Emory Medical Laboratory, Emory University School of Medicine, Atlanta, GA, USA
| | - Marc-Antoine de La Vega
- Department of Microbiology, Immunology & Infectious Diseases, Université Laval, Quebec City, QC, Canada
| | - Moses J Soka
- Partnership for Ebola Virus Disease Research in Liberia, Monrovia Medical Units ELWA-2 Hospital, Monrovia, Liberia
| | - Victoria Wahl
- National Biodefense Analysis and Countermeasures Center, Fort Detrick, Frederick, MD, USA
| | - Anthony Griffiths
- Department of Microbiology and National Emerging Infectious Diseases Laboratories, Boston University School of Medicine, Boston, MA, USA
| | - Laura Bollinger
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, MD, USA
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, MD, USA.
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26
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Matson MJ, Chertow DS, Munster VJ. Delayed recognition of Ebola virus disease is associated with longer and larger outbreaks. Emerg Microbes Infect 2020; 9:291-301. [PMID: 32013784 PMCID: PMC7034085 DOI: 10.1080/22221751.2020.1722036] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The average time required to detect an Ebola virus disease (EVD) outbreak following spillover of Ebola virus (EBOV) to a primary human case has remained essentially unchanged for over 40 years, with some of the longest delays in detection occurring in recent decades. In this review, our aim was to examine the relationship between delays in detection of EVD and the duration and size of outbreaks, and we report that longer delays are associated with longer and larger EVD outbreaks. Historically, EVD outbreaks have typically been comprised of less than 100 cases (median = 60) and have lasted less than 4 months (median = 118 days). The ongoing outbreak in Democratic Republic of the Congo, together with the 2013–2016 west Africa outbreak, are stark outliers amidst these trends and had two of the longest delays in detection on record. While significant progress has been made in the development of EVD countermeasures, implementation during EVD outbreaks is problematic. Thus, EVD surveillance must be improved by the broad deployment of modern diagnostic tools, as prompt recognition of EVD has the potential to stem early transmission and ultimately limit the duration and size of outbreaks.
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Affiliation(s)
- M Jeremiah Matson
- Laboratory of Virology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA.,Marshall University Joan C. Edwards School of Medicine, Huntington, WV, USA
| | - Daniel S Chertow
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Vincent J Munster
- Laboratory of Virology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
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27
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Shears P, Garavan C. The 2018/19 Ebola epidemic the Democratic Republic of the Congo (DRC): epidemiology, outbreak control, and conflict. Infect Prev Pract 2020; 2:100038. [PMID: 34368690 PMCID: PMC8336035 DOI: 10.1016/j.infpip.2020.100038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 11/28/2022] Open
Abstract
The Democratic Republic of Congo (DRC) (formerly Zaire) was the location of the first Ebola outbreak, in 1976, and since then there have been a total of ten outbreaks in different parts of the country. The current outbreak, the first in eastern DRC (North Kivu and Ituri provinces), began in July 2018, and by December 2019, there had been 3262 cases and 2232 deaths. Within weeks of the first reported cases, the World Health Organisation (WHO) and the DRC Ministry of Health (MOH) initiated a major response programme, with laboratory support, international agencies providing personnel, and material resources. Unlike previous Ebola outbreaks, including the west Africa epidemic, a proven vaccine, and trial therapeutic agents have been available as part of the outbreak response. Two therapeutic agents, mAb114 and REGN-EB3, both monoclonal antibody derived, have shown case fatality rates (CFR) of around 30%, compared to the overall of 66%. Despite these positive interventions, the outbreak has continued for eighteen months. Underlying the outbreak response has been a high number of violent incidents by local militias, and community mistrust and lack of involvement that has hampered many aspects of the response programme. As a result, many cases are not reported early and not transferred to treatment centres, deaths and increased transmission occur in the community, and the response programme is reaching only a proportion of the cases. New strategies to improve community participation, and integrate the Ebola response into the existing health structure are planned to improve the programme effectiveness.
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Affiliation(s)
- Paul Shears
- Wirral University Teaching Hospital, Wirral, Merseyside UK
| | - Carrie Garavan
- WHO Ebola Case Management Team, Butembo DRC & Medicines Sans Frontiers' Ebola Emergency Response Team DRC, Ireland
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28
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Wichmann O, Schaade L. Impfen im Kontext globaler Herausforderungen. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2020; 63:1-3. [PMID: 31828372 PMCID: PMC7223062 DOI: 10.1007/s00103-019-03073-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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29
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Chowell G, Tariq A, Kiskowski M. Vaccination strategies to control Ebola epidemics in the context of variable household inaccessibility levels. PLoS Negl Trop Dis 2019; 13:e0007814. [PMID: 31751337 PMCID: PMC6894888 DOI: 10.1371/journal.pntd.0007814] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 12/05/2019] [Accepted: 09/27/2019] [Indexed: 12/01/2022] Open
Abstract
Despite a very effective vaccine, active conflict and community distrust during the ongoing DRC Ebola epidemic are undermining control efforts, including a ring vaccination strategy that requires the prompt immunization of close contacts of infected individuals. However, in April 2019, it was reported 20% or more of close contacts cannot be reached or refuse vaccination, and it is predicted that the ring vaccination strategy would not be effective with such a high level of inaccessibility. The vaccination strategy is now incorporating a “third ring” community-level vaccination that targets members of communities even if they are not known contacts of Ebola cases. To assess the impact of vaccination strategies for controlling Ebola epidemics in the context of variable levels of community accessibility, we employed an individual-level stochastic transmission model that incorporates four sources of heterogeneity: a proportion of the population is inaccessible for contact tracing and vaccination due to lack of confidence in interventions or geographic inaccessibility, two levels of population mixing resembling household and community transmission, two types of vaccine doses with different time periods until immunity, and transmission rates that depend on spatial distance. Our results indicate that a ring vaccination strategy alone would not be effective for containing the epidemic in the context of significant delays to vaccinating contacts even for low levels of household inaccessibility and affirm the positive impact of a supplemental community vaccination strategy. Our key results are that as levels of inaccessibility increase, there is a qualitative change in the effectiveness of the vaccination strategy. For higher levels of vaccine access, the probability that the epidemic will end steadily increases over time, even if probabilities are lower than they would be otherwise with full community participation. For levels of vaccine access that are too low, however, the vaccination strategies are not expected to be successful in ending the epidemic even though they help lower incidence levels, which saves lives, and makes the epidemic easier to contain and reduces spread to other communities. This qualitative change occurs for both types of vaccination strategies: ring vaccination is effective for containing an outbreak until the levels of inaccessibility exceeds approximately 10% in the context of significant delays to vaccinating contacts, a combined ring and community vaccination strategy is effective until the levels of inaccessibility exceeds approximately 50%. More broadly, our results underscore the need to enhance community engagement to public health interventions in order to enhance the effectiveness of control interventions to ensure outbreak containment. In the context of the ongoing Ebola epidemic in DRC, active conflict and community distrust are undermining control efforts, including vaccination strategies. In this paper, we employed an individual-level stochastic structured transmission model to assess the impact of vaccination strategies on epidemic control in the context of variable levels of household inaccessibility. We found that a ring vaccination strategy of close contacts would not be effective for containing the epidemic in the context of significant delays to vaccinating contacts even for low levels of household inaccessibility and evaluate the impact of a supplemental community vaccination strategy. For lower levels of inaccessibility, the probability of epidemic containment increases over time. For higher levels of inaccessibility, even the combined ring and community vaccination strategies are not expected to contain the epidemic even though they help lower incidence levels, which saves lives, makes the epidemic easier to contain and reduces spread to other communities. We found that ring vaccination is effective for containing an outbreak until the levels of inaccessibility exceeds approximately 10%, a combined ring and community vaccination strategy is effective until the levels of inaccessibility exceeds approximately 50%. Our findings underscore the need to enhance community engagement to public health interventions.
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Affiliation(s)
- Gerardo Chowell
- Department of Population Health Sciences, School of Public Health, Georgia State University, Atlanta, GA, United States of America
- Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, MD, United States of America
- * E-mail: (GC); (AT); (MK)
| | - Amna Tariq
- Department of Population Health Sciences, School of Public Health, Georgia State University, Atlanta, GA, United States of America
- * E-mail: (GC); (AT); (MK)
| | - Maria Kiskowski
- Department of Mathematics and Statistics, University South Alabama, Mobile, AL, United States of America
- * E-mail: (GC); (AT); (MK)
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30
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Bedford J, Farrar J, Ihekweazu C, Kang G, Koopmans M, Nkengasong J. A new twenty-first century science for effective epidemic response. Nature 2019; 575:130-136. [PMID: 31695207 PMCID: PMC7095334 DOI: 10.1038/s41586-019-1717-y] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 09/24/2019] [Indexed: 12/20/2022]
Abstract
With rapidly changing ecology, urbanization, climate change, increased travel and fragile public health systems, epidemics will become more frequent, more complex and harder to prevent and contain. Here we argue that our concept of epidemics must evolve from crisis response during discrete outbreaks to an integrated cycle of preparation, response and recovery. This is an opportunity to combine knowledge and skills from all over the world-especially at-risk and affected communities. Many disciplines need to be integrated, including not only epidemiology but also social sciences, research and development, diplomacy, logistics and crisis management. This requires a new approach to training tomorrow's leaders in epidemic prevention and response.
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Affiliation(s)
| | | | | | - Gagandeep Kang
- Translational Health Science and Technology Institute, Faridabad, India
| | - Marion Koopmans
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - John Nkengasong
- Africa Centres for Disease Control and Prevention, African Union, Addis Ababa, Ethiopia
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31
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The exacerbation of Ebola outbreaks by conflict in the Democratic Republic of the Congo. Proc Natl Acad Sci U S A 2019; 116:24366-24372. [PMID: 31636188 DOI: 10.1073/pnas.1913980116] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The interplay between civil unrest and disease transmission is not well understood. Violence targeting healthcare workers and Ebola treatment centers in the Democratic Republic of the Congo (DRC) has been thwarting the case isolation, treatment, and vaccination efforts. The extent to which conflict impedes public health response and contributes to incidence has not previously been evaluated. We construct a timeline of conflict events throughout the course of the epidemic and provide an ethnographic appraisal of the local conditions that preceded and followed conflict events. Informed by temporal incidence and conflict data as well as the ethnographic evidence, we developed a model of Ebola transmission and control to assess the impact of conflict on the epidemic in the eastern DRC from April 30, 2018, to June 23, 2019. We found that both the rapidity of case isolation and the population-level effectiveness of vaccination varied notably as a result of preceding unrest and subsequent impact of conflict events. Furthermore, conflict events were found to reverse an otherwise declining phase of the epidemic trajectory. Our model framework can be extended to other infectious diseases in the same and other regions of the world experiencing conflict and violence.
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Redding DW, Atkinson PM, Cunningham AA, Lo Iacono G, Moses LM, Wood JLN, Jones KE. Impacts of environmental and socio-economic factors on emergence and epidemic potential of Ebola in Africa. Nat Commun 2019; 10:4531. [PMID: 31615986 PMCID: PMC6794280 DOI: 10.1038/s41467-019-12499-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 09/13/2019] [Indexed: 12/15/2022] Open
Abstract
Recent outbreaks of animal-borne emerging infectious diseases have likely been precipitated by a complex interplay of changing ecological, epidemiological and socio-economic factors. Here, we develop modelling methods that capture elements of each of these factors, to predict the risk of Ebola virus disease (EVD) across time and space. Our modelling results match previously-observed outbreak patterns with high accuracy, and suggest further outbreaks could occur across most of West and Central Africa. Trends in the underlying drivers of EVD risk suggest a 1.75 to 3.2-fold increase in the endemic rate of animal-human viral spill-overs in Africa by 2070, given current modes of healthcare intervention. Future global change scenarios with higher human population growth and lower rates of socio-economic development yield a fourfold higher likelihood of epidemics occurring as a result of spill-over events. Our modelling framework can be used to target interventions designed to reduce epidemic risk for many zoonotic diseases.
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Affiliation(s)
- David W Redding
- Centre for Biodiversity and Environment Research, Department of Genetics, Evolution and Environment, University College London, Gower Street, London, WC1E 6BT, UK.
| | - Peter M Atkinson
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA4 1YW, UK
| | - Andrew A Cunningham
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Gianni Lo Iacono
- School of Veterinary Medicine, University of Surrey, Guildford, UK
| | - Lina M Moses
- Department of Global Community Health and Behavioral Sciences, Tulane University, New Orleans, LA, USA
| | - James L N Wood
- Department of Veterinary Medicine, Disease Dynamics Unit, University of Cambridge, Cambridge, UK
| | - Kate E Jones
- Centre for Biodiversity and Environment Research, Department of Genetics, Evolution and Environment, University College London, Gower Street, London, WC1E 6BT, UK.
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK.
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Modelling microbial infection to address global health challenges. Nat Microbiol 2019; 4:1612-1619. [PMID: 31541212 PMCID: PMC6800015 DOI: 10.1038/s41564-019-0565-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 08/15/2019] [Indexed: 12/20/2022]
Abstract
The continued growth of the world’s population and increased interconnectivity heighten the risk that infectious diseases pose for human health worldwide. Epidemiological modelling is a tool that can be used to mitigate this risk by predicting disease spread or quantifying the impact of different intervention strategies on disease transmission dynamics. We illustrate how four decades of methodological advances and improved data quality have facilitated the contribution of modelling to address global health challenges, exemplified by models for the HIV crisis, emerging pathogens and pandemic preparedness. Throughout, we discuss the importance of designing a model that is appropriate to the research question and the available data. We highlight pitfalls that can arise in model development, validation and interpretation. Close collaboration between empiricists and modellers continues to improve the accuracy of predictions and the optimization of models for public health decision-making.
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Erb-Alvarez J, Wendelboe AM, Chertow DS. Ebola Virus in the Democratic Republic of the Congo: Advances and Remaining Obstacles in Epidemic Control, Clinical Care, and Biomedical Research. Chest 2019; 157:42-46. [PMID: 31518557 DOI: 10.1016/j.chest.2019.08.2183] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/01/2019] [Accepted: 08/19/2019] [Indexed: 11/15/2022] Open
Affiliation(s)
- Julie Erb-Alvarez
- Division of Intramural Research, Office of the Clinical Director, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Aaron M Wendelboe
- Department of Biostatistics and Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Daniel S Chertow
- Critical Care Medicine Department, Clinical Center and Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD.
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