scholarly journals Vaccine To Confer to Nonhuman Primates Complete Protection against Multistrain Ebola and Marburg Virus Infections

2008 ◽  
Vol 15 (3) ◽  
pp. 460-467 ◽  
Author(s):  
Dana L. Swenson ◽  
Danher Wang ◽  
Min Luo ◽  
Kelly L. Warfield ◽  
Jan Woraratanadharm ◽  
...  
Keyword(s):  
Nonhuman Primates ◽  
Ebola Virus ◽  
De Novo ◽  
Lethal Dose ◽  
Hemorrhagic Fever ◽  
Mortality Rates ◽  
Marburg Virus ◽  
Virus Infections ◽  
Biological Attack ◽  
Protection Against Infection

ABSTRACT Filoviruses (Ebola and Marburg viruses) are among the deadliest viruses known to mankind, with mortality rates nearing 90%. These pathogens are highly infectious through contact with infected body fluids and can be easily aerosolized. Additionally, there are currently no licensed vaccines available to prevent filovirus outbreaks. Their high mortality rates and infectious capabilities when aerosolized and the lack of licensed vaccines available to prevent such infectious make Ebola and Marburg viruses serious bioterrorism threats, placing them both on the category A list of bioterrorism agents. Here we describe a panfilovirus vaccine based on a complex adenovirus (CAdVax) technology that expresses multiple antigens from five different filoviruses de novo. Vaccination of nonhuman primates demonstrated 100% protection against infection by two species of Ebola virus and three Marburg virus subtypes, each administered at 1,000 times the lethal dose. This study indicates the feasibility of vaccination against all current filovirus threats in the event of natural hemorrhagic fever outbreak or biological attack.

scholarly journals Macaque Monoclonal Antibodies Targeting Novel Conserved Epitopes within Filovirus Glycoprotein

2015 ◽  
Vol 90 (1) ◽  
pp. 279-291 ◽  
Author(s):  
Zhen-Yong Keck ◽  
Sven G. Enterlein ◽  
Katie A. Howell ◽  
Hong Vu ◽  
Sergey Shulenin ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Nonhuman Primates ◽  
Ebola Virus ◽  
Virus Disease ◽  
Protective Efficacy ◽  
Hemorrhagic Fever ◽  
Marburg Virus ◽  
Human Pathogens ◽  
Content Type ◽  
The Core

ABSTRACTFiloviruses cause highly lethal viral hemorrhagic fever in humans and nonhuman primates. Current immunotherapeutic options for filoviruses are mostly specific to Ebola virus (EBOV), although other members ofFiloviridaesuch as Sudan virus (SUDV), Bundibugyo virus (BDBV), and Marburg virus (MARV) have also caused sizeable human outbreaks. Here we report a set of pan-ebolavirus and pan-filovirus monoclonal antibodies (MAbs) derived from cynomolgus macaques immunized repeatedly with a mixture of engineered glycoproteins (GPs) and virus-like particles (VLPs) for three different filovirus species. The antibodies recognize novel neutralizing and nonneutralizing epitopes on the filovirus glycoprotein, including conserved conformational epitopes within the core regions of the GP1 subunit and a novel linear epitope within the glycan cap. We further report the first filovirus antibody binding to a highly conserved epitope within the fusion loop of ebolavirus and marburgvirus species. One of the antibodies binding to the core GP1 region of all ebolavirus species and with lower affinity to MARV GP cross neutralized both SUDV and EBOV, the most divergent ebolavirus species. In a mouse model of EBOV infection, this antibody provided 100% protection when administered in two doses and partial, but significant, protection when given once at the peak of viremia 3 days postinfection. Furthermore, we describe novel cocktails of antibodies with enhanced protective efficacy compared to individual MAbs. In summary, the present work describes multiple novel, cross-reactive filovirus epitopes and innovative combination concepts that challenge the current therapeutic models.IMPORTANCEFiloviruses are among the most deadly human pathogens. The 2014-2015 outbreak of Ebola virus disease (EVD) led to more than 27,000 cases and 11,000 fatalities. While there are five species ofEbolavirusand several strains of marburgvirus, the current immunotherapeutics primarily target Ebola virus. Since the nature of future outbreaks cannot be predicted, there is an urgent need for therapeutics with broad protective efficacy against multiple filoviruses. Here we describe a set of monoclonal antibodies cross-reactive with multiple filovirus species. These antibodies target novel conserved epitopes within the envelope glycoprotein and exhibit protective efficacy in mice. We further present novel concepts for combination of cross-reactive antibodies against multiple epitopes that show enhanced efficacy compared to monotherapy and provide complete protection in mice. These findings set the stage for further evaluation of these antibodies in nonhuman primates and development of effective pan-filovirus immunotherapeutics for use in future outbreaks.

scholarly journals Ebola Virus ? A Global Threat

2015 ◽  
Vol 5 (1) ◽  
pp. 44-51
Author(s):  
Mejbah Uddin Ahmed ◽  
Sushmita Roy
Keyword(s):  
Nonhuman Primates ◽  
Ebola Virus ◽  
Rna Virus ◽  
Close Contact ◽  
Multiorgan Failure ◽  
Hemorrhagic Fever ◽  
Human Infection ◽  
Current Data ◽  
Sub Saharan Africa ◽  
Virus Infections

Ebola virus is a filamentous, enveloped, non-segmented, single-stranded, negative-sense RNA virus. It belongs to the Filoviridae and was first recognized near the Ebola River valley in Zaire in 1976. Since then most of the outbreaks have occurred to both human and nonhuman primates in sub-Saharan Africa. Ebola virus causes highly fatal hemorrhagic fever in human and nonhuman primates. In addition to hemorrhagic fever, it could be used as a bioterrorism agent. Although its natural reservoir is yet to be proven, current data suggest that fruit bats are the possibility. Infection has also been documented through the handling of infected chimpanzees, gorillas, monkeys, forest antelope and porcupines. Human infection is caused through close contact with the blood, secretion, organ or other body fluids of infected animal. Human-to-human transmission is also possible. Ebola virus infections are characterized by immune suppression and a systemic inflammatory response that causes impairment of the vascular, coagulation, and immune systems, leading to multiorgan failure and shock. The virus constitutes an important public health threat in Africa and also worldwide as no effective treatment or vaccine is available till now DOI: http://dx.doi.org/10.3329/jemc.v5i1.21497 J Enam Med Col 2015; 5(1): 44-51

scholarly journals Ebola and Marburg Viruses

2011 ◽  
Vol 6 (4) ◽  
pp. 381-389 ◽  
Author(s):  
Eri Nakayama ◽  
◽  
Ayato Takada
Keyword(s):  
Nonhuman Primates ◽  
Ebola Virus ◽  
Hemorrhagic Fever ◽  
Disease Outbreak ◽  
Marburg Virus ◽  
Virus Group ◽  
Imported Cases ◽  
Control Disease ◽  
Animal Reservoirs ◽  
Biosafety Level

Ebola and Marburg viruses, members of the filovirus family, cause severe hemorrhagic fever in human and nonhuman primates and are classified as biosafety level 4 agents. No effective filovirus-specific prophylaxis or treatment is yet commercially available. Filovirus species vary genetically, with one in the Marburg virus group and five in the Ebola virus group. Epidemiological efforts to prevent outbreaks lie mainly in identifying natural animal reservoirs. Increasingly frequent outbreaks in Africa and concerns about bioterrorism and imported cases in nonendemic areas point to the importance of public health in two ways – finding strategies to control disease outbreak and developing effective vaccines and drugs.

scholarly journals Recombinant Vesicular Stomatitis Virus Vector Mediates Postexposure Protection against Sudan Ebola Hemorrhagic Fever in Nonhuman Primates

2008 ◽  
Vol 82 (11) ◽  
pp. 5664-5668 ◽  
Author(s):  
Thomas W. Geisbert ◽  
Kathleen M. Daddario-DiCaprio ◽  
Kinola J. N. Williams ◽  
Joan B. Geisbert ◽  
Anders Leung ◽  
...  
Keyword(s):  
Vesicular Stomatitis Virus ◽  
Rhesus Monkeys ◽  
Nonhuman Primates ◽  
Ebola Virus ◽  
Rhesus Macaques ◽  
Hemorrhagic Fever ◽  
Marburg Virus ◽  
Ebola Hemorrhagic Fever ◽  
Zaire Ebolavirus ◽  
Vesicular Stomatitis

ABSTRACT Recombinant vesicular stomatitis virus (VSV) vectors expressing homologous filoviral glycoproteins can completely protect rhesus monkeys against Marburg virus when administered after exposure and can partially protect macaques after challenge with Zaire ebolavirus. Here, we administered a VSV vector expressing the Sudan ebolavirus (SEBOV) glycoprotein to four rhesus macaques shortly after exposure to SEBOV. All four animals survived SEBOV challenge, while a control animal that received a nonspecific vector developed fulminant SEBOV hemorrhagic fever and succumbed. This is the first demonstration of complete postexposure protection against an Ebola virus in nonhuman primates and provides further evidence that postexposure vaccination may have utility in treating exposures to filoviruses.

scholarly journals Identification and characterization of defective viral genomes in Ebola virus infected rhesus macaques

2021 ◽  
Author(s):  
Rebecca I. Johnson ◽  
Beata Boczkowska ◽  
Kendra Alfson ◽  
Taylor Weary ◽  
Heather Menzie ◽  
...  
Keyword(s):  
Nonhuman Primates ◽  
Ebola Virus ◽  
Sequence Data ◽  
Rna Virus ◽  
Hemorrhagic Fever ◽  
Marburg Virus ◽  
Immunostimulatory Activity ◽  
Viral Genomes

Ebola virus (EBOV), of the family Filoviridae, is an RNA virus that can cause hemorrhagic fever with a high mortality rate. Defective viral genomes (DVGs) are truncated genomes that have been observed during multiple RNA virus infections, including  in vitro EBOV infection, and have previously been associated with viral persistence and immunostimulatory activity. As DVGs have been detected in cells persistently infected with EBOV, we hypothesized that DVGs may also accumulate during viral replication in filovirus-infected hosts. Therefore, we interrogated sequence data from serum and tissues using a bioinformatics tool in order to identify the presence of DVGs in nonhuman primates (NHPs) infected with EBOV, Sudan virus (SUDV) or Marburg virus (MARV). Multiple 5’ copy-back DVGs (cbDVGs) were detected in NHP serum during the acute phase of filovirus infection. While the relative abundance of total DVGs in most animals was low, serum collected during acute EBOV and SUDV infections, but not MARV infection, contained a higher proportion of short trailer sequence cbDVGs than the challenge stock. This indicated an accumulation of these DVGs throughout infection, potentially due to the preferential replication of short DVGs over the longer viral genome. Using RT-PCR and deep sequencing, we also confirmed the presence of 5’ cbDVGs in EBOV-infected NHP testes, which is of interest due to EBOV persistence in semen of male survivors of infection. This work suggests that DVGs play a role in EBOV infection in vivo and further study will lead to a better understanding of EBOV pathogenesis. Importance The study of filovirus pathogenesis is critical for understanding the consequences of infection and the development of strategies to ameliorate future outbreaks. Defective viral genomes (DVGs) have been detected during EBOV infections in vitro , however their presence in in vivo infections remains unknown. In this study, DVGs were detected in samples collected from EBOV- and SUDV-infected nonhuman primates (NHPs). The accumulation of these DVGs in the trailer region of the genome during infection indicates a potential role in EBOV and SUDV pathogenesis. In particular, the presence of DVGs in the testes of infected NHPs requires further investigation as it may be linked to the establishment of persistence.

scholarly journals Single-Injection Vaccine Protects Nonhuman Primates against Infection with Marburg Virus and Three Species of Ebola Virus

2009 ◽  
Vol 83 (14) ◽  
pp. 7296-7304 ◽  
Author(s):  
Thomas W. Geisbert ◽  
Joan B. Geisbert ◽  
Anders Leung ◽  
Kathleen M. Daddario-DiCaprio ◽  
Lisa E. Hensley ◽  
...  
Keyword(s):  
Nonhuman Primates ◽  
Ebola Virus ◽  
Single Injection ◽  
Hemorrhagic Fever ◽  
Marburg Virus ◽  
Lethal Challenge ◽  
Glycoprotein G ◽  
Unvaccinated Control ◽  
Zaire Ebolavirus ◽  
Vesicular Stomatitis

ABSTRACT The filoviruses Marburg virus and Ebola virus cause severe hemorrhagic fever with high mortality in humans and nonhuman primates. Among the most promising filovirus vaccines under development is a system based on recombinant vesicular stomatitis virus (VSV) that expresses a single filovirus glycoprotein (GP) in place of the VSV glycoprotein (G). Here, we performed a proof-of-concept study in order to determine the potential of having one single-injection vaccine capable of protecting nonhuman primates against Sudan ebolavirus (SEBOV), Zaire ebolavirus (ZEBOV), Cote d'Ivoire ebolavirus (CIEBOV), and Marburgvirus (MARV). In this study, 11 cynomolgus monkeys were vaccinated with a blended vaccine consisting of equal parts of the vaccine vectors VSVΔG/SEBOVGP, VSVΔG/ZEBOVGP, and VSVΔG/MARVGP. Four weeks later, three of these animals were challenged with MARV, three with CIEBOV, three with ZEBOV, and two with SEBOV. Three control animals were vaccinated with VSV vectors encoding a nonfilovirus GP and challenged with SEBOV, ZEBOV, and MARV, respectively, and five unvaccinated control animals were challenged with CIEBOV. Importantly, none of the macaques vaccinated with the blended vaccine succumbed to a filovirus challenge. As expected, an experimental control animal vaccinated with VSVΔG/ZEBOVGP and challenged with SEBOV succumbed, as did the positive controls challenged with SEBOV, ZEBOV, and MARV, respectively. All five control animals challenged with CIEBOV became severely ill, and three of the animals succumbed on days 12, 12, and 14, respectively. The two animals that survived CIEBOV infection were protected from subsequent challenge with either SEBOV or ZEBOV, suggesting that immunity to CIEBOV may be protective against other species of Ebola virus. In conclusion, we developed an immunization scheme based on a single-injection vaccine that protects nonhuman primates against lethal challenge with representative strains of all human pathogenic filovirus species.

scholarly journals Two Complex, Adenovirus-Based Vaccines That Together Induce Immune Responses to All Four Dengue Virus Serotypes

2006 ◽  
Vol 14 (2) ◽  
pp. 182-189 ◽  
Author(s):  
David H. Holman ◽  
Danher Wang ◽  
Kanakatte Raviprakash ◽  
Nicholas U. Raja ◽  
Min Luo ◽  
...  
Keyword(s):  
Immune Responses ◽  
Dengue Virus ◽  
Vaccine Development ◽  
De Novo ◽  
Natural Infection ◽  
Hemorrhagic Fever ◽  
Virus Infections ◽  
Dengue Vaccine ◽  
Membrane Antigens ◽  
Dengue Virus Serotypes

ABSTRACT Dengue virus infections can cause hemorrhagic fever, shock, encephalitis, and even death. Worldwide, approximately 2.5 billion people live in dengue-infested regions with about 100 million new cases each year, although many of these infections are believed to be silent. There are four antigenically distinct serotypes of dengue virus; thus, immunity from one serotype will not cross-protect from infection with the other three. The difficulties that hamper vaccine development include requirements of the natural conformation of the envelope glycoprotein to induce neutralizing immune responses and the necessity of presenting antigens of all four serotypes. Currently, the only way to meet these requirements is to use a mixture of four serotypes of live attenuated dengue viruses, but safety remains a major problem. In this study, we have developed the basis for a tetravalent dengue vaccine using a novel complex adenovirus platform that is capable of expressing multiple antigens de novo. This dengue vaccine is constructed as a pair of vectors that each expresses the premembrane and envelope genes of two different dengue virus serotypes. Upon vaccination, the vaccine expressed high levels of the dengue virus antigens in cells to mimic a natural infection and induced both humoral and cellular immune responses against multiple serotypes of dengue virus in an animal model. Further analyses show the humoral responses were indeed neutralizing against all four serotypes. Our studies demonstrate the concept of mimicking infections to induce immune responses by synthesizing dengue virus membrane antigens de novo and the feasibility of developing an effective tetravalent dengue vaccine by vector-mediated expression of glycoproteins of the four serotypes.

scholarly journals Equine-Origin Immunoglobulin Fragments Protect Nonhuman Primates from Ebola Virus Disease

2018 ◽  
Vol 93 (5) ◽  
Author(s):  
Hualei Wang ◽  
Gary Wong ◽  
Wenjun Zhu ◽  
Shihua He ◽  
Yongkun Zhao ◽  
...  
Keyword(s):  
Large Scale ◽  
Nonhuman Primates ◽  
Ebola Virus ◽  
Virus Disease ◽  
Hemorrhagic Fever ◽  
West African ◽  
Clinical Testing ◽  
The Past ◽  
Over 40 Years

ABSTRACT Ebola virus (EBOV) infections result in aggressive hemorrhagic fever in humans, with fatality rates reaching 90% and with no licensed specific therapeutics to treat ill patients. Advances over the past 5 years have firmly established monoclonal antibody (MAb)-based products as the most promising therapeutics for treating EBOV infections, but production is costly and quantities are limited; therefore, MAbs are not the best candidates for mass use in the case of an epidemic. To address this need, we generated EBOV-specific polyclonal F(ab′)2 fragments from horses hyperimmunized with an EBOV vaccine. The F(ab′)2 was found to potently neutralize West African and Central African EBOV in vitro. Treatment of nonhuman primates (NHPs) with seven doses of 100 mg/kg F(ab′)2 beginning 3 or 5 days postinfection (dpi) resulted in a 100% survival rate. Notably, NHPs for which treatment was initiated at 5 dpi were already highly viremic, with observable signs of EBOV disease, which demonstrated that F(ab′)2 was still effective as a therapeutic agent even in symptomatic subjects. These results show that F(ab′)2 should be advanced for clinical testing in preparation for future EBOV outbreaks and epidemics. IMPORTANCE EBOV is one of the deadliest viruses to humans. It has been over 40 years since EBOV was first reported, but no cure is available. Research breakthroughs over the past 5 years have shown that MAbs constitute an effective therapy for EBOV infections. However, MAbs are expensive and difficult to produce in large amounts and therefore may only play a limited role during an epidemic. A cheaper alternative is required, especially since EBOV is endemic in several third world countries with limited medical resources. Here, we used a standard protocol to produce large amounts of antiserum F(ab′)2 fragments from horses vaccinated with an EBOV vaccine, and we tested the protectiveness in monkeys. We showed that F(ab′)2 was effective in 100% of monkeys even after the animals were visibly ill with EBOV disease. Thus, F(ab′)2 could be a very good option for large-scale treatments of patients and should be advanced to clinical testing.

scholarly journals Previremic Identification of Ebola or Marburg Virus Infection Using Integrated Host-Transcriptome and Viral Genome Detection

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Emily Speranza ◽  
Ignacio Caballero ◽  
Anna N. Honko ◽  
Joshua C. Johnson ◽  
J. Kyle Bohannon ◽  
...  
Keyword(s):  
Host Response ◽  
Nonhuman Primates ◽  
Ebola Virus ◽  
Clinical Symptoms ◽  
Infectious Agent ◽  
Marburg Virus ◽  
Viral Rna ◽  
Molecular Tests ◽  
Early Replication ◽  
Host Infection

ABSTRACT Outbreaks of filoviruses, such as those caused by the Ebola (EBOV) and Marburg (MARV) virus, are difficult to detect and control. The initial clinical symptoms of these diseases are nonspecific and can mimic other endemic pathogens. This makes confident diagnosis based on clinical symptoms alone impossible. Molecular diagnostics for these diseases that rely on the detection of viral RNA in the blood are only effective after significant disease progression. As an approach to identify these infections earlier in the disease course, we tested the effectiveness of viral RNA detection combined with an assessment of sentinel host mRNAs that are upregulated following filovirus infection. RNAseq analysis of EBOV-infected nonhuman primates identified host RNAs that are upregulated at early stages of infection. NanoString probes that recognized these host-response RNAs were combined with probes that recognized viral RNA and were used to classify viral infection both prior to viremia and postviremia. This approach was highly successful at identifying samples from nonhuman primate subjects and correctly distinguished the causative agent in a previremic stage in 10 EBOV and 5 MARV samples. This work suggests that unified host response/viral fingerprint assays can enable diagnosis of disease earlier than testing for viral nucleic acid alone, which could decrease transmission events and increase therapeutic effectiveness. IMPORTANCE Current molecular tests that identify infection with high-consequence viruses such as Ebola virus and Marburg virus are based on the detection of virus material in the blood. These viruses do not undergo significant early replication in the blood and, instead, replicate in organs such as the liver and spleen. Thus, virus begins to accumulate in the blood only after significant replication has already occurred in those organs, making viremia an indicator of infection only after initial stages have become established. Here, we show that a multianalyte assay can correctly identify the infectious agent in nonhuman primates (NHPs) prior to viremia through tracking host infection response transcripts. This illustrates that a single-tube, sample-to-answer format assay could be used to advance the time at which the type of infection can be determined and thereby improve outcomes.

Viral hemorrhagic fever – a vascular disease?

2003 ◽  
Vol 89 (06) ◽  
pp. 967-972 ◽  
Author(s):  
Heinz Feldmann ◽  
Hans Schnittler
Keyword(s):  
Ebola Virus ◽  
Vascular System ◽  
Current Knowledge ◽  
Hemorrhagic Fever ◽  
Host Cells ◽  
Fluid Distribution ◽  
Target Cells ◽  
Viral Hemorrhagic Fever ◽  
Virus Infections ◽  
Cytokines And Chemokines

SummaryThe syndrome of “viral hemorrhagic fever” in man caused by certain viruses, such as Ebola, Lassa, Dengue, and Crimean-Congo hemorrhagic fever viruses, is often associated with a shock syndrome of undetermined pathogenesis. However, the vascular system, particularly the vascular endothelium, seems to be directly and indirectly targeted by all these viruses. Here we briefly summarize the current knowledge on Marburg and Ebola virus infections, the prototype viral hemorrhagic fever agents, and formulate a working hypothesis for the pathogenesis of viral hemorrhagic fever. Infections with filoviruses show lethality up to 89% and in severe cases lead to a shock syndrome associated with hypotension, coagulation disorders and an imbalance of fluid distribution between the intravascular and extravascular tissue space. The primary target cells for filovi-ruses are mononuclear phagocytotic cells which are activated upon infection and release certain cytokines and chemokines. These mediators indirectly target the endothelium and are thought to play a key role in the pathogenesis of filoviral hemorrhagic fever. In addition, direct infection and subsequent destruction of endothelial cells might contribute to the pathogenesis. Filoviruses, particularly Ebola virus, encode nonstructural glycoproteins which are released from infected host cells. Their function as potential determinants in pathogenicity remains to be investigated.

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