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Marceau J, Safronetz D, Martellaro C, Marzi A, Rosenke K, Feldmann H. Bivalent VSV Vectors Mediate Rapid and Potent Protection from Andes Virus Challenge in Hamsters. Viruses 2024; 16:279. [PMID: 38400054 PMCID: PMC10893017 DOI: 10.3390/v16020279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/08/2024] [Accepted: 02/09/2024] [Indexed: 02/25/2024] Open
Abstract
Orthohantaviruses may cause hemorrhagic fever with renal syndrome or hantavirus cardiopulmonary syndrome. Andes virus (ANDV) is the only orthohantavirus associated with human-human transmission. Therefore, emergency vaccination would be a valuable public health measure to combat ANDV-derived infection clusters. Here, we utilized a promising vesicular stomatitis virus (VSV)-based vaccine to advance the approach for emergency applications. We compared monovalent and bivalent VSV vectors containing the Ebola virus (EBOV), glycoprotein (GP), and ANDV glycoprotein precursor (GPC) for protective efficacy in pre-, peri- and post-exposure immunization by the intraperitoneal and intranasal routes. Inclusion of the EBOV GP was based on its favorable immune cell targeting and the strong innate responses elicited by the VSV-EBOV vaccine. Our data indicates no difference of ANDV GPC expressing VSV vectors in pre-exposure immunization independent of route, but a potential benefit of the bivalent VSVs following peri- and post-exposure intraperitoneal vaccination.
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Affiliation(s)
- Joshua Marceau
- Laboratory of Virology, Division of Intramural Research, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA; (J.M.); (D.S.); (C.M.)
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT 59812, USA
| | - David Safronetz
- Laboratory of Virology, Division of Intramural Research, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA; (J.M.); (D.S.); (C.M.)
| | - Cynthia Martellaro
- Laboratory of Virology, Division of Intramural Research, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA; (J.M.); (D.S.); (C.M.)
| | - Andrea Marzi
- Laboratory of Virology, Division of Intramural Research, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA; (J.M.); (D.S.); (C.M.)
| | - Kyle Rosenke
- Laboratory of Virology, Division of Intramural Research, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA; (J.M.); (D.S.); (C.M.)
| | - Heinz Feldmann
- Laboratory of Virology, Division of Intramural Research, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA; (J.M.); (D.S.); (C.M.)
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Woolsey C, Borisevich V, Agans KN, O’Toole R, Fenton KA, Harrison MB, Prasad AN, Deer DJ, Gerardi C, Morrison N, Cross RW, Eldridge JH, Matassov D, Geisbert TW. A Highly Attenuated Panfilovirus VesiculoVax Vaccine Rapidly Protects Nonhuman Primates Against Marburg Virus and 3 Species of Ebola Virus. J Infect Dis 2023; 228:S660-S670. [PMID: 37171813 PMCID: PMC11009496 DOI: 10.1093/infdis/jiad157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/01/2023] [Accepted: 05/09/2023] [Indexed: 05/13/2023] Open
Abstract
BACKGROUND The family Filoviridae consists of several virus members known to cause significant mortality and disease in humans. Among these, Ebola virus (EBOV), Marburg virus (MARV), Sudan virus (SUDV), and Bundibugyo virus (BDBV) are considered the deadliest. The vaccine, Ervebo, was shown to rapidly protect humans against Ebola disease, but is indicated only for EBOV infections with limited cross-protection against other filoviruses. Whether multivalent formulations of similar recombinant vesicular stomatitis virus (rVSV)-based vaccines could likewise confer rapid protection is unclear. METHODS Here, we tested the ability of an attenuated, quadrivalent panfilovirus VesiculoVax vaccine (rVSV-Filo) to elicit fast-acting protection against MARV, EBOV, SUDV, and BDBV. Groups of cynomolgus monkeys were vaccinated 7 days before exposure to each of the 4 viral pathogens. All subjects (100%) immunized 1 week earlier survived MARV, SUDV, and BDBV challenge; 80% survived EBOV challenge. Survival correlated with lower viral load, higher glycoprotein-specific immunoglobulin G titers, and the expression of B-cell-, cytotoxic cell-, and antigen presentation-associated transcripts. CONCLUSIONS These results demonstrate multivalent VesiculoVax vaccines are suitable for filovirus outbreak management. The highly attenuated nature of the rVSV-Filo vaccine may be preferable to the Ervebo "delta G" platform, which induced adverse events in a subset of recipients.
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Affiliation(s)
- Courtney Woolsey
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Viktoriya Borisevich
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Krystle N Agans
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Rachel O’Toole
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Karla A Fenton
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Mack B Harrison
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Abhishek N Prasad
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Daniel J Deer
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Cheryl Gerardi
- Department of Viral Vaccine Development, Auro Vaccines, Pearl River, New York, USA
| | - Nneka Morrison
- Department of Viral Vaccine Development, Auro Vaccines, Pearl River, New York, USA
| | - Robert W Cross
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - John H Eldridge
- Department of Viral Vaccine Development, Auro Vaccines, Pearl River, New York, USA
| | - Demetrius Matassov
- Department of Viral Vaccine Development, Auro Vaccines, Pearl River, New York, USA
| | - Thomas W Geisbert
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
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Abstract
INTRODUCTION Filoviruses are negative-stranded, enveloped RNA viruses that can cause hemorrhagic fever in humans and include Ebola and Marburg viruses. Lethality rates can reach 90% in isolated outbreaks. The 2013-2016 Ebola virus epidemic demonstrated the global threat of filoviruses and hastened development of vaccines and therapeutics. There are six known filoviruses that cause disease in humans, but still few therapeutics are available for treatment. AREAS COVERED This review summarizes identification, testing, and development of therapeutics based on the peer-reviewed scientific literature beginning with the discovery of filoviruses in 1967. Small molecules, antibodies, cytokines, antisense, post-exposure vaccination, and host-targeted therapeutic approaches are discussed. An emphasis is placed on therapeutics that have shown promise in in vivo studies. EXPERT OPINION Two monoclonal antibody regimens are approved for use in humans for one filovirus (Ebola virus), and preclinical nonhuman primate studies suggest that other monoclonal-based therapies are likely to be effective against other filoviruses. Significant progress has been made in small-molecule antivirals and host-targeted approaches. An important consideration is the necessity of pan-filovirus therapeutics via broadly effective small molecules, antibody cocktails, and cross-reactive antibodies. The use of filovirus therapeutics as prophylactic treatment or in chronically infected individuals should be considered.
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Affiliation(s)
- Steven B Bradfute
- Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, USA
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Pinski AN, Messaoudi I. Therapeutic vaccination strategies against EBOV by rVSV-EBOV-GP: the role of innate immunity. Curr Opin Virol 2021; 51:179-189. [PMID: 34749265 DOI: 10.1016/j.coviro.2021.10.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 10/14/2021] [Accepted: 10/19/2021] [Indexed: 12/30/2022]
Abstract
Zaire Ebola virus (EBOV) is a member of the Filoviridae family. Infection with EBOV causes Ebola virus disease (EVD) characterized by excessive inflammation, lymphocyte death, coagulopathy, and multi-organ failure. In 2019, the FDA-approved the first anti-EBOV vaccine, rVSV-EBOV-GP (Ervebo® by Merck). This live-recombinant vaccine confers both prophylactic and therapeutic protection to nonhuman primates and humans. While mechanisms conferring prophylactic protection are well-investigated, those underlying protection conferred shortly before and after exposure to EBOV remain poorly understood. In this review, we review data from in vitro and in vivo studies analyzing early immune responses to rVSV-EBOV-GP and discuss the role of innate immune activation in therapeutic protection.
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Affiliation(s)
- Amanda N Pinski
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA
| | - Ilhem Messaoudi
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA; Center for Virus Research, University of California, Irvine, Irvine, CA, USA; Institute for Immunology, University of California, Irvine, Irvine, CA, USA; Department of Microbiology, Immunology and Molecular Genetics, College of Medicine, University of Kentucky, Lexington, KY, USA.
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Jaspard M, Juchet S, Serra B, Mayoum B, Kanta IM, Camara MS, Mbala P, Kojan R, Malvy D. Post-exposure prophylaxis following high-risk contact with Ebola virus, using immunotherapies with monoclonal antibodies, in the eastern Democratic Republic of the Congo: an emergency use program. Int J Infect Dis 2021; 113:166-167. [PMID: 34587535 DOI: 10.1016/j.ijid.2021.09.053] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION With the development of therapeutics and vaccine against Ebola virus disease (EVD), the question of post-exposure prophylaxis for high-risk contact has emerged. Immunotherapies (monoclonal antibodies [mAbs]) recently validated for treating infected patients appear to be a good candidate for protecting contacts. DESIGN During the tenth EVD outbreak in the Democratic Republic of the Congo, we have administrated mAbs (Mab114 or REGN-EB3) to high and intermediate-risk contacts of EVD patients. RESULTS Overall, 23 non-vaccinated contacts received mAbs after a median delay between contact and post-exposure prophylaxis of 1 day (interquartile range 1-2). All contacts were free of symptoms, and all had negative reverse transcriptase-polymerase chain reaction 14 days after the contact. CONCLUSION Immunotherapies appear to be promising candidates to protect EVD contacts. Interaction with vaccine needs to be analyzed and a larger study on efficacy conducted.
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Affiliation(s)
- Marie Jaspard
- University of Bordeaux, National Institute for Health and Medical Research (Inserm), Research Institute for Sustainable Development (IRD), Bordeaux Population Health Center, UMR 1219, Bordeaux, France; The Alliance for International Medical Action, Dakar, Senegal.
| | - Sylvain Juchet
- University of Bordeaux, National Institute for Health and Medical Research (Inserm), Research Institute for Sustainable Development (IRD), Bordeaux Population Health Center, UMR 1219, Bordeaux, France; The Alliance for International Medical Action, Dakar, Senegal.
| | - Béatrice Serra
- University of Bordeaux, National Institute for Health and Medical Research (Inserm), Research Institute for Sustainable Development (IRD), Bordeaux Population Health Center, UMR 1219, Bordeaux, France; The Alliance for International Medical Action, Dakar, Senegal.
| | - Baweye Mayoum
- The Alliance for International Medical Action, Dakar, Senegal.
| | | | | | - Placide Mbala
- Institut National de la Recherche Biomedicale, Kinshasa, Democratic Republic of the Congo.
| | - Richard Kojan
- The Alliance for International Medical Action, Dakar, Senegal.
| | - Denis Malvy
- University of Bordeaux, National Institute for Health and Medical Research (Inserm), Research Institute for Sustainable Development (IRD), Bordeaux Population Health Center, UMR 1219, Bordeaux, France; Department for infections and tropical diseases, University Hospital of Bordeaux, Bordeaux, France.
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Tshiani Mbaya O, Mukumbayi P, Mulangu S. Review: Insights on Current FDA-Approved Monoclonal Antibodies Against Ebola Virus Infection. Front Immunol 2021; 12:721328. [PMID: 34526994 PMCID: PMC8435780 DOI: 10.3389/fimmu.2021.721328] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 08/12/2021] [Indexed: 11/29/2022] Open
Abstract
The unprecedented 2013-2016 West Africa Ebola outbreak accelerated several medical countermeasures (MCMs) against Ebola virus disease (EVD). Several investigational products (IPs) were used throughout the outbreak but were not conclusive for efficacy results. Only the Randomized Controlled Trial (RCT) on ZMapp was promising but inconclusive. More recently, during the second-largest Ebola outbreak in North Kivu and Ituri provinces, Democratic Republic of the Congo (DRC), four IPs, including one small molecule (Remdesivir), two monoclonal antibody (mAb) cocktails (ZMapp and REGN-EB3) and a single mAb (mAb114), were evaluated in an RCT, the Pamoja Tulinde Maisha (PALM) study. Two products (REGN-EB3 and mAb114) demonstrated efficacy as compared to the control arm, ZMapp. There were remarkably few side effects recorded in the trial. The FDA approved both medications in this scientifically sound study, marking a watershed moment in the field of EVD therapy. These products can be produced relatively inexpensively and can be stockpiled. The administration of mAbs in EVD patients appears to be safe and effective, while several critical knowledge gaps remain; the impact of early administration of Ebola-specific mAbs on developing a robust immune response for future Ebola virus exposure is unknown. The viral mutation escape, leading to resistance, presents a potential limitation for single mAb therapy; further improvements need to be explored. Understanding the contribution of Fc-mediated antibody functions such as antibody-dependent cellular cytotoxicity (ADCC) of those approved mAbs is still critical. The potential merit of combination therapy and post-exposure prophylaxis (PEP) need to be demonstrated. Furthermore, the PALM trial has accounted for 30% of mortality despite the administration of specific treatments. The putative role of EBOV soluble Glycoprotein (sGP) as a decoy to the immune system, the virus persistence, and relapses might be investigated for treatment failure. The development of pan-filovirus or pan-species mAbs remains essential for protection. The interaction between FDA-approved mAbs and vaccines remains unclear and needs to be investigated. In this review, we summarize the efficacy and safety results of the PALM study and review current research questions for the further development of mAbs in pre-exposure or emergency post-exposure use.
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Affiliation(s)
- Olivier Tshiani Mbaya
- Clinical Monitoring Research Program Directorate, Leidos Biomedical Research, Frederick, MD, United States
| | - Philippe Mukumbayi
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Sabue Mulangu
- Global Medical Affairs, Ridgeback Biotherapeutics, Miami, FL, United States
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7
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Hargreaves A, Brady C, Mellors J, Tipton T, Carroll MW, Longet S. Filovirus Neutralising Antibodies: Mechanisms of Action and Therapeutic Application. Pathogens 2021; 10:pathogens10091201. [PMID: 34578233 PMCID: PMC8468515 DOI: 10.3390/pathogens10091201] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/10/2021] [Accepted: 09/12/2021] [Indexed: 12/02/2022] Open
Abstract
Filoviruses, especially Ebola virus, cause sporadic outbreaks of viral haemorrhagic fever with very high case fatality rates in Africa. The 2013–2016 Ebola epidemic in West Africa provided large survivor cohorts spurring a large number of human studies which showed that specific neutralising antibodies played a key role in protection following a natural Ebola virus infection, as part of the overall humoral response and in conjunction with the cellular adaptive response. This review will discuss the studies in survivors and animal models which described protective neutralising antibody response. Their mechanisms of action will be detailed. Furthermore, the importance of neutralising antibodies in antibody-based therapeutics and in vaccine-induced responses will be explained, as well as the strategies to avoid immune escape from neutralising antibodies. Understanding the neutralising antibody response in the context of filoviruses is crucial to furthering our understanding of virus structure and function, in addition to improving current vaccines & antibody-based therapeutics.
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Affiliation(s)
- Alexander Hargreaves
- Nuffield Department of Medicine, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; (A.H.); (C.B.); (J.M.); (T.T.); (M.W.C.)
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK
| | - Caolann Brady
- Nuffield Department of Medicine, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; (A.H.); (C.B.); (J.M.); (T.T.); (M.W.C.)
| | - Jack Mellors
- Nuffield Department of Medicine, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; (A.H.); (C.B.); (J.M.); (T.T.); (M.W.C.)
- National Infection Service, Public Health England, Porton Down, Salisbury SP4 0JG, UK
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L69 7ZX, UK
| | - Tom Tipton
- Nuffield Department of Medicine, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; (A.H.); (C.B.); (J.M.); (T.T.); (M.W.C.)
| | - Miles W. Carroll
- Nuffield Department of Medicine, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; (A.H.); (C.B.); (J.M.); (T.T.); (M.W.C.)
- National Infection Service, Public Health England, Porton Down, Salisbury SP4 0JG, UK
| | - Stephanie Longet
- Nuffield Department of Medicine, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; (A.H.); (C.B.); (J.M.); (T.T.); (M.W.C.)
- Correspondence: ; Tel.: +44-18-6561-7892
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8
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Abstract
Introduction. The consistent emergence/reemergence of filoviruses into a world that previously lacked an approved pharmaceutical intervention parallels an experience repeatedly played-out for most other emerging pathogenic zoonotic viruses. Investment to preemptively develop effective and low-cost prophylactic and therapeutic interventions against viruses that have high potential for emergence and societal impact should be a priority.Areas covered. Candidate drugs can be characterized into those that interfere with cellular processes required for Ebola virus (EBOV) replication (host-directed), and those that directly target virally encoded functions (direct-acting). We discuss strategies to identify pharmaceutical interventions for EBOV infections. PubMed/Web of Science databases were searched to establish a detailed catalog of these interventions.Expert opinion. Many drug candidates show promising in vitro inhibitory activity, but experience with EBOV shows the general lack of translation to in vivo efficacy for host-directed repurposed drugs. Better translation is seen for direct-acting antivirals, in particular monoclonal antibodies. The FDA-approved monoclonal antibody treatment, Inmazeb™ is a success story that could be improved in terms of impact on EBOV-associated disease and mortality, possibly by combination with other direct-acting agents targeting distinct aspects of the viral replication cycle. Costs need to be addressed given EBOV emergence primarily in under-resourced countries.
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Affiliation(s)
- Frederick Hansen
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Heinz Feldmann
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Michael A Jarvis
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA.,School of Biomedical Sciences, University of Plymouth, Plymouth, Devon, UK.,The Vaccine Group, Ltd, Plymouth, Devon, UK
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9
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Cross RW, Bornholdt ZA, Prasad AN, Borisevich V, Agans KN, Deer DJ, Abelson DM, Kim DH, Shestowsky WS, Campbell LA, Bunyan E, Geisbert JB, Fenton KA, Zeitlin L, Porter DP, Geisbert TW. Combination therapy protects macaques against advanced Marburg virus disease. Nat Commun 2021; 12:1891. [PMID: 33767178 DOI: 10.1038/s41467-021-22132-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 03/03/2021] [Indexed: 11/08/2022] Open
Abstract
Monoclonal antibodies (mAbs) and remdesivir, a small-molecule antiviral, are promising monotherapies for many viruses, including members of the genera Marburgvirus and Ebolavirus (family Filoviridae), and more recently, SARS-CoV-2. One of the major challenges of acute viral infections is the treatment of advanced disease. Thus, extending the window of therapeutic intervention is critical. Here, we explore the benefit of combination therapy with a mAb and remdesivir in a non-human primate model of Marburg virus (MARV) disease. While rhesus monkeys are protected against lethal infection when treatment with either a human mAb (MR186-YTE; 100%), or remdesivir (80%), is initiated 5 days post-inoculation (dpi) with MARV, no animals survive when either treatment is initiated alone beginning 6 dpi. However, by combining MR186-YTE with remdesivir beginning 6 dpi, significant protection (80%) is achieved, thereby extending the therapeutic window. These results suggest value in exploring combination therapy in patients presenting with advanced filovirus disease.
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10
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Pinski AN, Messaoudi I. To B or Not to B: Mechanisms of Protection Conferred by rVSV-EBOV-GP and the Roles of Innate and Adaptive Immunity. Microorganisms 2020; 8:E1473. [PMID: 32992829 DOI: 10.3390/microorganisms8101473] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 12/28/2022] Open
Abstract
Zaire Ebola virus (EBOV) is a member of the Filoviridae family of negative sense, single-stranded RNA viruses. EBOV infection causes Ebola virus disease (EVD), characterized by coagulopathy, lymphopenia, and multi-organ failure, which can culminate in death. In 2019, the FDA approved the first vaccine against EBOV, a recombinant live-attenuated viral vector wherein the G protein of vesicular stomatitis virus is replaced with the glycoprotein (GP) of EBOV (rVSV-EBOV-GP, Ervebo® by Merck). This vaccine demonstrates high efficacy in nonhuman primates by providing prophylactic, rapid, and post-exposure protection. In humans, rVSV-EBOV-GP demonstrated 100% protection in several phase III clinical trials in over 10,000 individuals during the 2013–2016 West Africa epidemic. As of 2020, over 218,000 doses of rVSV-EBOV-GP have been administered to individuals with high risk of EBOV exposure. Despite licensure and robust preclinical studies, the mechanisms of rVSV-EBOV-GP-mediated protection are not fully understood. Such knowledge is crucial for understanding vaccine-mediated correlates of protection from EVD and to aid the further design and development of therapeutics against filoviruses. Here, we summarize the current literature regarding the host response to vaccination and EBOV exposure, and evidence regarding innate and adaptive immune mechanisms involved in rVSV-EBOV-GP-mediated protection, with a focus on the host transcriptional response. Current data strongly suggest a protective synergy between rapid innate and humoral immunity.
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