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Berger L, Skerratt LF, Kosch TA, Brannelly LA, Webb RJ, Waddle AW. Advances in Managing Chytridiomycosis for Australian Frogs: Gradarius Firmus Victoria. Annu Rev Anim Biosci 2024; 12:113-133. [PMID: 38358840 DOI: 10.1146/annurev-animal-021122-100823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Extensive knowledge gains from research worldwide over the 25 years since the discovery of chytridiomycosis can be used for improved management. Strategies that have saved populations in the short term and/or enabled recovery include captive breeding, translocation into disease refugia, translocation from resistant populations, disease-free exclosures, and preservation of disease refuges with connectivity to previous habitat, while antifungal treatments have reduced mortality rates in the wild. Increasing host resistance is the goal of many strategies under development, including vaccination and targeted genetic interventions. Pathogen-directed strategies may be more challenging but would have broad applicability. While the search for the silver bullet solution continues, we should value targeted local interventions that stop extinction and buy time for evolution of resistance or development of novel solutions. As for most invasive species and infectious diseases, we need to accept that ongoing management is necessary. For species continuing to decline, proactive deployment and assessment of promising interventions are more valid than a hands-off, do-no-harm approach that will likely allow further extinctions.
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Affiliation(s)
- Lee Berger
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Lee F Skerratt
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Tiffany A Kosch
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Laura A Brannelly
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Rebecca J Webb
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Anthony W Waddle
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
- Applied Biosciences, Macquarie University, Sydney, New South Wales, Australia;
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2
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Rupprecht CE, Mshelbwala PP, Reeves RG, Kuzmin IV. Rabies in a postpandemic world: resilient reservoirs, redoubtable riposte, recurrent roadblocks, and resolute recidivism. ANIMAL DISEASES 2023; 3:15. [PMID: 37252063 PMCID: PMC10195671 DOI: 10.1186/s44149-023-00078-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 04/02/2023] [Indexed: 05/31/2023] Open
Abstract
Rabies is an ancient disease. Two centuries since Pasteur, fundamental progress occurred in virology, vaccinology, and diagnostics-and an understanding of pathobiology and epizootiology of rabies in testament to One Health-before common terminological coinage. Prevention, control, selective elimination, and even the unthinkable-occasional treatment-of this zoonosis dawned by the twenty-first century. However, in contrast to smallpox and rinderpest, eradication is a wishful misnomer applied to rabies, particularly post-COVID-19 pandemic. Reasons are minion. Polyhostality encompasses bats and mesocarnivores, but other mammals represent a diverse spectrum of potential hosts. While rabies virus is the classical member of the genus, other species of lyssaviruses also cause the disease. Some reservoirs remain cryptic. Although global, this viral encephalitis is untreatable and often ignored. As with other neglected diseases, laboratory-based surveillance falls short of the notifiable ideal, especially in lower- and middle-income countries. Calculation of actual burden defaults to a flux within broad health economic models. Competing priorities, lack of defined, long-term international donors, and shrinking local champions challenge human prophylaxis and mass dog vaccination toward targets of 2030 for even canine rabies impacts. For prevention, all licensed vaccines are delivered to the individual, whether parenteral or oral-essentially 'one and done'. Exploiting mammalian social behaviors, future 'spreadable vaccines' might increase the proportion of immunized hosts per unit effort. However, the release of replication-competent, genetically modified organisms selectively engineered to spread intentionally throughout a population raises significant biological, ethical, and regulatory issues in need of broader, transdisciplinary discourse. How this rather curious idea will evolve toward actual unconventional prevention, control, or elimination in the near term remains debatable. In the interim, more precise terminology and realistic expectations serve as the norm for diverse, collective constituents to maintain progress in the field.
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Affiliation(s)
- Charles E. Rupprecht
- College of Forestry, Wildlife & Environment, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 USA
| | - Philip P. Mshelbwala
- School of Veterinary Science, University of Queensland, Gatton, Australia
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Abuja, Abuja, Nigeria
| | - R. Guy Reeves
- Max Planck Institut Für Evolutionsbiologie, 24306 Plön, Germany
| | - Ivan V. Kuzmin
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
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3
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Griffiths ME, Meza DK, Haydon DT, Streicker DG. Inferring the disruption of rabies circulation in vampire bat populations using a betaherpesvirus-vectored transmissible vaccine. Proc Natl Acad Sci U S A 2023; 120:e2216667120. [PMID: 36877838 PMCID: PMC10089182 DOI: 10.1073/pnas.2216667120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 01/25/2023] [Indexed: 03/08/2023] Open
Abstract
Transmissible vaccines are an emerging biotechnology that hold prospects to eliminate pathogens from wildlife populations. Such vaccines would genetically modify naturally occurring, nonpathogenic viruses ("viral vectors") to express pathogen antigens while retaining their capacity to transmit. The epidemiology of candidate viral vectors within the target wildlife population has been notoriously challenging to resolve but underpins the selection of effective vectors prior to major investments in vaccine development. Here, we used spatiotemporally replicated deep sequencing to parameterize competing epidemiological mechanistic models of Desmodus rotundus betaherpesvirus (DrBHV), a proposed vector for a transmissible vaccine targeting vampire bat-transmitted rabies. Using 36 strain- and location-specific time series of prevalence collected over 6 y, we found that lifelong infections with cycles of latency and reactivation, combined with a high R0 (6.9; CI: 4.39 to 7.85), are necessary to explain patterns of DrBHV infection observed in wild bats. These epidemiological properties suggest that DrBHV may be suited to vector a lifelong, self-boosting, and transmissible vaccine. Simulations showed that inoculating a single bat with a DrBHV-vectored rabies vaccine could immunize >80% of a bat population, reducing the size, frequency, and duration of rabies outbreaks by 50 to 95%. Gradual loss of infectious vaccine from vaccinated individuals is expected but can be countered by inoculating larger but practically achievable proportions of bat populations. Parameterizing epidemiological models using accessible genomic data brings transmissible vaccines one step closer to implementation.
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Affiliation(s)
- Megan E. Griffiths
- Medical Research Council–University of Glasgow Centre for Virus Research, GlasgowG61 1QH, United Kingdom
| | - Diana K. Meza
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, GlasgowG61 1QH, United Kingdom
| | - Daniel T. Haydon
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, GlasgowG61 1QH, United Kingdom
| | - Daniel G. Streicker
- Medical Research Council–University of Glasgow Centre for Virus Research, GlasgowG61 1QH, United Kingdom
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, GlasgowG61 1QH, United Kingdom
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4
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Griffiths ME, Broos A, Bergner LM, Meza DK, Suarez NM, da Silva Filipe A, Tello C, Becker DJ, Streicker DG. Longitudinal deep sequencing informs vector selection and future deployment strategies for transmissible vaccines. PLoS Biol 2022; 20:e3001580. [PMID: 35439242 PMCID: PMC9017877 DOI: 10.1371/journal.pbio.3001580] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 02/21/2022] [Indexed: 12/04/2022] Open
Abstract
Vaccination is a powerful tool in combating infectious diseases of humans and companion animals. In most wildlife, including reservoirs of emerging human diseases, achieving sufficient vaccine coverage to mitigate disease burdens remains logistically unattainable. Virally vectored "transmissible" vaccines that deliberately spread among hosts are a potentially transformative, but still theoretical, solution to the challenge of immunising inaccessible wildlife. Progress towards real-world application is frustrated by the absence of frameworks to guide vector selection and vaccine deployment prior to major in vitro and in vivo investments in vaccine engineering and testing. Here, we performed deep sequencing on field-collected samples of Desmodus rotundus betaherpesvirus (DrBHV), a candidate vector for a transmissible vaccine targeting vampire bat-transmitted rabies. We discovered 11 strains of DrBHV that varied in prevalence and geographic distribution across Peru. The phylogeographic structure of DrBHV strains was predictable from both host genetics and landscape topology, informing long-term DrBHV-vectored vaccine deployment strategies and identifying geographic areas for field trials where vaccine spread would be naturally contained. Multistrain infections were observed in 79% of infected bats. Resampling of marked individuals over 4 years showed within-host persistence kinetics characteristic of latency and reactivation, properties that might boost individual immunity and lead to sporadic vaccine transmission over the lifetime of the host. Further, strain acquisitions by already infected individuals implied that preexisting immunity and strain competition are unlikely to inhibit vaccine spread. Our results support the development of a transmissible vaccine targeting a major source of human and animal rabies in Latin America and show how genomics can enlighten vector selection and deployment strategies for transmissible vaccines.
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Affiliation(s)
- Megan E. Griffiths
- MRC–University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Alice Broos
- MRC–University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Laura M. Bergner
- MRC–University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Diana K. Meza
- MRC–University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Nicolas M. Suarez
- MRC–University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Ana da Silva Filipe
- MRC–University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Carlos Tello
- Association for the Conservation and Development of Natural Resources, Lima, Peru
- Yunkawasi, Lima, Peru
| | - Daniel J. Becker
- Department of Biology, University of Oklahoma, Norman, Oklahoma, United States of America
| | - Daniel G. Streicker
- MRC–University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
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5
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Quantifying the effectiveness of betaherpesvirus-vectored transmissible vaccines. Proc Natl Acad Sci U S A 2022; 119:2108610119. [PMID: 35046024 PMCID: PMC8794881 DOI: 10.1073/pnas.2108610119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2021] [Indexed: 11/26/2022] Open
Abstract
Spillover of infectious diseases from wildlife populations into humans is an increasing threat to human health and welfare. Current approaches to manage these emerging infectious diseases are largely reactive, leading to deadly and costly time lags between emergence and control. Here, we use mathematical models and data from previously published experimental and field studies to evaluate the scope for a more proactive approach based on transmissible vaccines that eliminates pathogens from wild animal populations before spillover can occur. Our models are focused on transmissible vaccines designed using herpes virus vectors and demonstrate that these vaccines—currently under development for several important human pathogens—may have the potential to rapidly control zoonotic pathogens within the reservoir hosts. Transmissible vaccines have the potential to revolutionize how zoonotic pathogens are controlled within wildlife reservoirs. A key challenge that must be overcome is identifying viral vectors that can rapidly spread immunity through a reservoir population. Because they are broadly distributed taxonomically, species specific, and stable to genetic manipulation, betaherpesviruses are leading candidates for use as transmissible vaccine vectors. Here we evaluate the likely effectiveness of betaherpesvirus-vectored transmissible vaccines by developing and parameterizing a mathematical model using data from captive and free-living mouse populations infected with murine cytomegalovirus (MCMV). Simulations of our parameterized model demonstrate rapid and effective control for a range of pathogens, with pathogen elimination frequently occurring within a year of vaccine introduction. Our results also suggest, however, that the effectiveness of transmissible vaccines may vary across reservoir populations and with respect to the specific vector strain used to construct the vaccine.
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6
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Serwer P, Wright ET, De La Chapa J, Gonzales CB. Basics for Improved Use of Phages for Therapy. Antibiotics (Basel) 2021; 10:antibiotics10060723. [PMID: 34208477 PMCID: PMC8234457 DOI: 10.3390/antibiotics10060723] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/07/2021] [Accepted: 06/10/2021] [Indexed: 12/17/2022] Open
Abstract
Blood-borne therapeutic phages and phage capsids increasingly reach therapeutic targets as they acquire more persistence, i.e., become more resistant to non-targeted removal from blood. Pathogenic bacteria are targets during classical phage therapy. Metastatic tumors are potential future targets, during use of drug delivery vehicles (DDVs) that are phage derived. Phage therapy has, to date, only sometimes been successful. One cause of failure is low phage persistence. A three-step strategy for increasing persistence is to increase (1) the speed of lytic phage isolation, (2) the diversity of phages isolated, and (3) the effectiveness and speed of screening phages for high persistence. The importance of high persistence-screening is illustrated by our finding here of persistence dramatically higher for coliphage T3 than for its relative, coliphage T7, in murine blood. Coliphage T4 is more persistent, long-term than T3. Pseudomonas chlororaphis phage 201phi2-1 has relatively low persistence. These data are obtained with phages co-inoculated and separately assayed. In addition, highly persistent phage T3 undergoes dispersal to several murine organs and displays tumor tropism in epithelial tissue (xenografted human oral squamous cell carcinoma). Dispersal is an asset for phage therapy, but a liability for phage-based DDVs. We propose increased focus on phage persistence—and dispersal—screening.
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Affiliation(s)
- Philip Serwer
- Department of Biochemistry and Structural Biology, The University of Texas Health Center, San Antonio, TX 78229-3900, USA;
- Correspondence: ; Tel.: +1-210-567-3765
| | - Elena T. Wright
- Department of Biochemistry and Structural Biology, The University of Texas Health Center, San Antonio, TX 78229-3900, USA;
| | - Jorge De La Chapa
- Department of Comprehensive Dentistry, The University of Texas Health Center, San Antonio, TX 78229-3900, USA; (J.D.L.C.); (C.B.G.)
| | - Cara B. Gonzales
- Department of Comprehensive Dentistry, The University of Texas Health Center, San Antonio, TX 78229-3900, USA; (J.D.L.C.); (C.B.G.)
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7
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Layman NC, Tuschhoff BM, Basinski AJ, Remien CH, Bull JJ, Nuismer SL. Suppressing evolution in genetically engineered systems through repeated supplementation. Evol Appl 2021; 14:348-359. [PMID: 33664781 PMCID: PMC7896713 DOI: 10.1111/eva.13119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 07/09/2020] [Accepted: 08/13/2020] [Indexed: 11/29/2022] Open
Abstract
Genetically engineered organisms are prone to evolve in response to the engineering. This evolution is often undesirable and can negatively affect the purpose of the engineering. Methods that maintain the stability of engineered genomes are therefore critical to the successful design and use of genetically engineered organisms. One potential method to limit unwanted evolution is by taking advantage of the ability of gene flow to counter local adaption, a process of supplementation. Here, we investigate the feasibility of supplementation as a mechanism to offset the evolutionary degradation of a transgene in three model systems: a bioreactor, a gene drive, and a transmissible vaccine. In each model, continual introduction from a stock is used to balance mutation and selection against the transgene. Each system has its unique features. The bioreactor system is especially tractable and has a simple answer: The level of supplementation required to maintain the transgene at a frequency p ^ is approximatelyp ^ s , where s is the selective disadvantage of the transgene. Supplementation is also feasible in the transmissible vaccine case but is probably not practical to prevent the evolution of resistance against a gene drive. We note, however, that the continual replacement of even a small fraction of a large population can be challenging, limiting the usefulness of supplementation as a means of controlling unwanted evolution.
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Affiliation(s)
| | | | | | | | - James J. Bull
- Department of Biological SciencesUniversity of IdahoMoscowIDUSA
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8
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Layman NC, Tuschhoff BM, Nuismer SL. Designing transmissible viral vaccines for evolutionary robustness and maximum efficiency. Virus Evol 2021; 7:veab002. [PMID: 33680502 PMCID: PMC7920745 DOI: 10.1093/ve/veab002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The danger posed by emerging infectious diseases necessitates the development of new tools that can mitigate the risk of animal pathogens spilling over into the human population. One promising approach is the development of recombinant viral vaccines that are transmissible, and thus capable of self-dissemination through hard to reach populations of wild animals. Indeed, mathematical models demonstrate that transmissible vaccines can greatly reduce the effort required to control the spread of zoonotic pathogens in their animal reservoirs, thereby limiting the chances of human infection. A key challenge facing these new vaccines, however, is the inevitability of evolutionary change resulting from their ability to self-replicate and generate extended chains of transmission. Further, carrying immunogenic transgenes is often costly, in terms of metabolic burden, increased competition with the pathogen, or due to unintended interactions with the viral host regulatory network. As a result, natural selection is expected to favor vaccine strains that down-regulate or delete these transgenes resulting in increased rates of transmission and reduced efficacy against the target pathogen. In addition, efficacy and evolutionary stability will often be at odds; as when longer, more efficacious antigens experience faster rates of evolutionary decay. Here, we ask how such trade-offs influence the overall performance of transmissible vaccines. We find that evolutionary instability can substantially reduce performance, even for vaccine candidates with the ideal combination of efficacy and transmission. However, we find that, at least in some cases, vaccine stability and overall performance can be improved by the inclusion of a second, redundant antigen. Overall, our results suggest that the successful application of recombinant transmissible vaccines will require consideration of evolutionary dynamics and epistatic effects, as well as basic measurements of epidemiological features.
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Affiliation(s)
| | - Beth M Tuschhoff
- Department of Mathematics, University of Idaho, 875 Perimeter Drive, Moscow, ID 83844, USA
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Chaudhry SN, Hazafa A, Mumtaz M, Kalsoom U, Abbas S, Kainaat A, Bilal S, Zafar N, Siddique A, Zafar A. New insights on possible vaccine development against SARS-CoV-2. Life Sci 2020; 260:118421. [PMID: 32926920 PMCID: PMC7484811 DOI: 10.1016/j.lfs.2020.118421] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/08/2020] [Accepted: 09/08/2020] [Indexed: 02/07/2023]
Abstract
In December 2019, a novel virus, namely COVID-19 caused by SARS-CoV-2, developed from Wuhan, (Hubei territory of China) used its viral spike glycoprotein receptor-binding domain (RBD) for the entrance into a host cell by binding with ACE-2 receptor and cause acute respiratory distress syndrome (ARDS). Data revealed that the newly emerged SARS-CoV-2 affected more than 24,854,140 people with 838,924 deaths worldwide. Until now, no licensed immunization or drugs are present for the medication of SARS-CoV-2. The present review aims to investigate the latest developments and discuss the candidate antibodies in different vaccine categories to develop a reliable and efficient vaccine against SARS-CoV-2 in a short time duration. Besides, the review focus on the present challenges and future directions, structure, and mechanism of SARS-CoV-2 for a better understanding. Based on data, we revealed that most of the vaccines are focus on targeting the spike protein (S) of COVID-19 to neutralized viral infection and develop long-lasting immunity. Up to phase-1 clinical trials, some vaccines showed the specific antigen-receptor T-cell response, elicit the humoral and immune response, displayed tight binding with human-leukocytes-antigen (HLA), and recognized specific antibodies to provoke long-lasting immunity against SARS-CoV-2.
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Affiliation(s)
- Sundas Nasir Chaudhry
- Department of Biochemistry, Faculty of Sciences, University of Agriculture, Faisalabad 38000, Pakistan
| | - Abu Hazafa
- Department of Biochemistry, Faculty of Sciences, University of Agriculture, Faisalabad 38000, Pakistan.
| | - Muhummad Mumtaz
- Department of Chemistry, Faculty of Sciences, University of Agriculture, Faisalabad 38000, Pakistan
| | - Ume Kalsoom
- Institute of Biochemistry and Biotechnology, University of the Punjab, Lahore 54000, Pakistan
| | - Saima Abbas
- Department of Biochemistry, Kinnaird College for Women Lahore, 54000, Pakistan
| | - Amna Kainaat
- School of Biological Sciences, University of the Punjab, Lahore 54000, Pakistan
| | - Shahid Bilal
- Department of Agronomy, Faculty of Agriculture, University of Agriculture, Faisalabad 38000, Pakistan
| | - Nauman Zafar
- Department of Chemistry, Faculty of Sciences, University of Agriculture, Faisalabad 38000, Pakistan
| | - Aleena Siddique
- MBBS, Rashid Latif Medical and Dental College, Lahore 54000, Pakistan
| | - Ayesha Zafar
- Institute of Biochemistry and Biotechnology, Faculty of Biosciences, University of Veterinary and Animal Sciences, Lahore, Pakistan
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10
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Nuismer SL, Bull JJ. Self-disseminating vaccines to suppress zoonoses. Nat Ecol Evol 2020; 4:1168-1173. [PMID: 32719452 DOI: 10.1038/s41559-020-1254-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 06/22/2020] [Indexed: 01/08/2023]
Abstract
The SARS-CoV-2 epidemic is merely the most recent demonstration that our current approach to emerging zoonotic infectious disease is ineffective. SARS, MERS, Ebola, Nipah and an array of arenavirus infections sporadically spillover into human populations and are often contained only as a result of their poor transmission in human hosts, coupled with intense public health control efforts in the early stages of an emerging epidemic. It is now more apparent than ever that we need a better and more proactive approach. One possibility is to eliminate the threat of spillover before it occurs using vaccines capable of autonomously spreading through wild animal reservoirs. We are now poised to begin developing self-disseminating vaccines targeting a wide range of human pathogens, but important decisions remain about how they can be most effectively designed and used to target pathogens with a high risk of spillover and/or emergence. In this Perspective, we first review the basic epidemiological theory establishing the feasibility and utility of self-disseminating vaccines. We then outline a road map for overcoming remaining technical challenges: identifying high-risk pathogens before they emerge, optimizing vaccine design with an eye to evolution, behaviour and epidemiology, and minimizing the risk of unintended consequences.
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Affiliation(s)
- Scott L Nuismer
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA. .,Department of Mathematics, University of Idaho, Moscow, ID, USA.
| | - James J Bull
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
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11
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Sanal MG, Dubey RC. An oral live attenuated vaccine strategy against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2/2019-nCoV). RESEARCH IDEAS AND OUTCOMES 2020. [DOI: 10.3897/rio.6.e53767] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2/2019-nCoV) infection has become a pandemic called COVID-19. The virus binds to angiotensin converting enzyme 2 (ACE2) and TMPRSS2 which are abundantly expressed on various human cells including lung epithelial cells and intestinal cells and the virus can infect these cells. Currently no specific treatments or vaccines are available for this disease. A per oral live attenuated vaccine can be a good strategy in SARS-CoV-2 infection because the attenuated virus initially infects the gut, stimulates the mucosa associated immune system sparing the respiratory system during the initial immune response. The live virus can also spread in the community boosting herd immunity.
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