RESUMO
Lassa virus (LASV) causes mild to severe hemorrhagic fever disease in humans. Strain 13/N guinea pigs are highly susceptible to infection with LASV strain Josiah (clade IV), providing a critical model system for therapeutics and vaccine development. To develop additional models of disease, we detail the clinical course in guinea pigs infected with 5 geographically and genetically diverse LASV strains. Two of the developed models (LASV clades II and III) were then used to evaluate efficacy of a virus replicon particle vaccine against heterologous LASV challenge, demonstrating complete protection against clinical disease after a single vaccination dose.
Assuntos
Febre Lassa , Vacinas Virais , Humanos , Cobaias , Animais , Vírus Lassa , Replicon , VacinaçãoRESUMO
Although bats are increasingly being recognized as natural reservoir hosts of emerging zoonotic viruses, little is known about how they control and clear virus infection in the absence of clinical disease. Here, we test >50 convalescent sera from Egyptian rousette bats (ERBs) experimentally primed or prime-boosted with Marburg virus, Ebola virus, or Sosuga virus for the presence of virus-specific neutralizing antibodies, using infectious reporter viruses. After serum neutralization testing, we conclude that antibody-mediated virus neutralization does not contribute significantly to the control and clearance of Marburg virus, Ebola virus, or Sosuga virus infection in ERBs.
Assuntos
Quirópteros/virologia , Ebolavirus/imunologia , Doença pelo Vírus Ebola/imunologia , Doença do Vírus de Marburg/imunologia , Marburgvirus/imunologia , Paramyxoviridae/imunologia , Animais , Anticorpos Antivirais/imunologia , Convalescença , Reservatórios de Doenças/virologia , Egito/epidemiologia , Doença pelo Vírus Ebola/virologia , Humanos , Imunidade Humoral , Doença do Vírus de Marburg/virologia , Testes de NeutralizaçãoRESUMO
Lassa fever is a frequently severe human disease that is endemic to several countries in West Africa. To date, no licensed vaccines are available to prevent Lassa virus (LASV) infection, even though Lassa fever is thought to be an important disease contributing to mortality and both acute and chronic morbidity. We have previously described a vaccine candidate composed of single-cycle LASV replicon particles (VRPs) and a stable cell line for their production. Here, we refine the genetic composition of the VRPs and demonstrate the ability to reproducibly purify them with high yields. Studies in the guinea pig model confirm efficacy of the vaccine candidate, demonstrate that single-cycle replication is necessary for complete protection by the VRP vaccine, and show that postexposure vaccination can confer protection from lethal outcome.
Assuntos
Febre Lassa/prevenção & controle , Vírus Lassa/imunologia , Profilaxia Pós-Exposição/métodos , Vacinação/métodos , Vacinas Virais/administração & dosagem , Células A549 , África Ocidental , Animais , Chlorocebus aethiops , Modelos Animais de Doenças , Feminino , Cobaias , Humanos , Esquemas de Imunização , Febre Lassa/virologia , Vírus Lassa/genética , Vírus Lassa/isolamento & purificação , Masculino , Replicon/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Células Vero , Vacinas Virais/genética , Vacinas Virais/imunologiaRESUMO
Lassa virus (LASV), a hemorrhagic fever virus endemic to West Africa, causes conjunctivitis in patients with acute disease. To examine ocular manifestations of LASV, we histologically examined eyes from infected guinea pigs. In fatal disease, LASV immunostaining was most prominent in the anterior uvea, especially in the filtration angle, ciliary body, and iris and in and around vessels in the bulbar conjunctiva and peripheral cornea, where it co-localized with an endothelial marker (platelet endothelial cell adhesion molecule). Antigen was primarily associated with infiltration of T-lymphocytes around vessels in the anterior uvea and with new vessel formation at the peripheral cornea. In animals that exhibited clinical signs but survived infection, eyes had little to no inflammation and no LASV immunostaining 6 weeks after infection. Overall, in this model, LASV antigen was restricted to the anterior uvea and was associated with mild chronic inflammation in animals with severe disease but was not detected in survivors.
Assuntos
Conjuntivite/virologia , Endotélio Corneano/virologia , Irite/virologia , Ceratite/virologia , Vírus Lassa/fisiologia , Animais , Biópsia , Conjuntivite/patologia , Modelos Animais de Doenças , Endotélio Corneano/patologia , Feminino , Cobaias , Imuno-Histoquímica , Irite/patologia , Ceratite/patologia , Masculino , Reação em Cadeia da Polimerase , RNA ViralRESUMO
Lassa fever is a viral zoonosis that can be transmitted from person to person, especially in the hospital setting. The disease is endemic to several countries in West Africa and can be a major contributor to morbidity and mortality in affected areas. There are no approved vaccines to prevent Lassa virus infection. In this work, we present a vaccine candidate that combines the scalability and efficacy benefits of a live vaccine with the safety benefits of single-cycle replication. The system consists of Lassa virus replicon particles devoid of the virus essential glycoprotein gene, and a cell line that expresses the glycoprotein products, enabling efficient vaccine propagation. Guinea pigs vaccinated with these particles showed no clinical reaction to the inoculum and were protected against fever, weight loss, and lethality after infection with Lassa virus.
Assuntos
Febre Lassa/imunologia , Vírus Lassa/imunologia , Replicon/imunologia , Vacinas Virais/imunologia , África Ocidental , Animais , Linhagem Celular , Chlorocebus aethiops , Modelos Animais de Doenças , Cobaias , Vacinas Atenuadas/imunologia , Células VeroRESUMO
Among the survivors of Ebola virus disease (EVD), complications that include uveitis can develop during convalescence, although the incidence and pathogenesis of EVD-associated uveitis are unknown. We describe a patient who recovered from EVD and was subsequently found to have severe unilateral uveitis during convalescence. Viable Zaire ebolavirus (EBOV) was detected in aqueous humor 14 weeks after the onset of EVD and 9 weeks after the clearance of viremia.
Assuntos
Humor Aquoso/virologia , Ebolavirus/isolamento & purificação , Doença pelo Vírus Ebola/complicações , Pan-Uveíte/virologia , Transtornos da Visão/virologia , Adulto , Convalescença , Fundo de Olho , Humanos , MasculinoRESUMO
Modern ebolavirus diagnostics rely primarily on quantitative reverse transcription-polymerase chain reaction (qRT-PCR), a sensitive method to detect viral genetic material in the acute phase of the disease. However, qRT-PCR does not confirm presence of infectious virus, presenting limitations in patient and outbreak management. Attempts to isolate infectious virus rely on in vivo or basic cell culture approaches, which prohibit rapid results and screening. In this study, we present a novel reporter cell line capable of detecting live ebolaviruses. These cells permit sensitive, large-scale screening and titration of infectious virus in experimental and clinical samples, independent of ebolavirus species and variant.
Assuntos
Ebolavirus/genética , Ebolavirus/isolamento & purificação , Doença pelo Vírus Ebola/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Animais , Técnicas de Cultura de Células , Linhagem Celular , Chlorocebus aethiops , Genoma Viral , Doença pelo Vírus Ebola/virologia , Humanos , Técnicas de Diagnóstico Molecular/instrumentação , RNA Viral/sangue , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e Especificidade , Células VeroRESUMO
During the Ebola virus outbreak of 2013-2016, the Viral Special Pathogens Branch field laboratory in Sierra Leone tested approximately 26 000 specimens between August 2014 and October 2015. Analysis of the B2M endogenous control Ct values showed its utility in monitoring specimen quality, comparing results with different specimen types, and interpretation of results. For live patients, blood is the most sensitive specimen type and oral swabs have little diagnostic utility. However, swabs are highly sensitive for diagnostic testing of corpses.
Assuntos
Surtos de Doenças , Ebolavirus/isolamento & purificação , Doença pelo Vírus Ebola/diagnóstico , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Serviços de Laboratório Clínico , Ebolavirus/genética , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/virologia , Humanos , Laboratórios , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e Especificidade , Serra Leoa/epidemiologiaRESUMO
We investigated the duration of Ebola virus (EBOV) RNA and infectious EBOV in semen specimens of 5 Ebola virus disease (EVD) survivors. EBOV RNA and infectious EBOV was detected by real-time RT-PCR and virus culture out to 290 days and 70 days, respectively, after EVD onset.
Assuntos
Ebolavirus/isolamento & purificação , Doença pelo Vírus Ebola/virologia , Sêmen/virologia , Adulto , Estudos de Coortes , Ebolavirus/patogenicidade , Humanos , Masculino , SobreviventesRESUMO
BACKGROUND: The rVSVΔG-ZEBOV-GP Ebola vaccine (rVSV-ZEBOV) has been used in response to Ebola disease outbreaks caused by Ebola virus (EBOV). Understanding Ebola knowledge, attitudes, and practices (KAP) and the long-term immune response following rVSV-ZEBOV are critical to inform recommendations on future use. METHODS: We administered surveys and collected blood samples from healthcare workers (HCWs) from seven Ugandan healthcare facilities. Questionnaires collected information on demographic characteristics and KAP related to Ebola and vaccination. IgG ELISA, virus neutralization, and interferon gamma ELISpot measured immunological responses against EBOV glycoprotein (GP). RESULTS: Overall, 37 % (210/565) of HCWs reported receiving any Ebola vaccination. Knowledge that rVSV-ZEBOV only protects against EBOV was low among vaccinated (32 %; 62/192) and unvaccinated (7 %; 14/200) HCWs. Most vaccinated (91 %; 192/210) and unvaccinated (92 %; 326/355) HCWs wanted to receive a booster or initial dose of rVSV-ZEBOV, respectively. Median time from rVSV-ZEBOV vaccination to sample collection was 37.7 months (IQR: 30.5, 38.3). IgG antibodies against EBOV GP were detected in 95 % (61/64) of HCWs with vaccination cards and in 84 % (162/194) of HCWs who reported receiving a vaccination. Geometric mean titer among seropositive vaccinees was 0.066 IU/mL (95 % CI: 0.058-0.076). CONCLUSION: As Uganda has experienced outbreaks of Sudan virus and Bundibugyo virus, for which rVSV-ZEBOV does not protect against, our findings underscore the importance of continued education and risk communication to HCWs on Ebola and other viral hemorrhagic fevers. IgG antibodies against EBOV GP were detected in most vaccinated HCWs in Uganda 2â4 years after vaccination; however, the duration and correlates of protection warrant further investigation.
Assuntos
Anticorpos Antivirais , Vacinas contra Ebola , Ebolavirus , Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde , Doença pelo Vírus Ebola , Vacinação , Humanos , Pessoal de Saúde/estatística & dados numéricos , Uganda , Doença pelo Vírus Ebola/prevenção & controle , Doença pelo Vírus Ebola/imunologia , Masculino , Feminino , Vacinas contra Ebola/imunologia , Vacinas contra Ebola/administração & dosagem , Adulto , Ebolavirus/imunologia , Anticorpos Antivirais/sangue , Vacinação/métodos , Pessoa de Meia-Idade , Inquéritos e Questionários , Imunoglobulina G/sangue , Adulto JovemRESUMO
Ebola disease outbreaks are major public health events because of human-to-human transmission and high mortality. These outbreaks are most often caused by Ebola virus, but at least three related viruses can also cause the disease. In 2022, Sudan virus re-emerged causing more than 160 confirmed and probable cases. This report describes generation of a recombinant Sudan virus and demonstrates its utility by quantifying antibody cross-reactivity between Ebola and Sudan virus glycoproteins after human infection or vaccination with a licensed Ebola virus vaccine.
Assuntos
Ebolavirus , Doença pelo Vírus Ebola , Humanos , Doença pelo Vírus Ebola/prevenção & controle , Anticorpos Antivirais , Ebolavirus/genética , Vacinação , Glicoproteínas/genéticaRESUMO
Nipah virus (NiV) is a highly pathogenic paramyxovirus with a high case fatality rate. Due to its high pathogenicity, pandemic potential, and lack of therapeutics or approved vaccines, its study requires biosafety level 4 (BSL4) containment. In this report, we developed a novel neutralization assay for use in biosafety level 2 laboratories. The assay uses a recombinant vesicular stomatitis virus expressing NiV glycoprotein and a fluorescent protein. The recombinant virus propagates as a replication-competent virus in a cell line constitutively expressing NiV fusion protein, but it is restricted to a single round of replication in wild-type cells. We used this system to evaluate the neutralization activity of monoclonal and polyclonal antibodies, plasma from NiV-infected hamsters, and serum from human patients. Therefore, this recombinant virus could be used as a surrogate for using pathogenic NiV and may constitute a powerful tool to develop therapeutics in low containment laboratories.
RESUMO
Nipah virus (NiV) causes a highly lethal disease in humans who present with acute respiratory or neurological signs. No vaccines against NiV have been approved to date. Here, we report on the clinical impact of a novel NiV-derived nonspreading replicon particle lacking the fusion (F) protein gene (NiVΔF) as a vaccine in three small animal models of disease. A broad antibody response was detected that included immunoglobulin G (IgG) and IgA subtypes with demonstrable Fc-mediated effector function targeting multiple viral antigens. Single-dose intranasal vaccination up to 3 days before challenge prevented clinical signs and reduced virus levels in hamsters and immunocompromised mice; decreases were seen in tissues and mucosal secretions, critically decreasing potential for virus transmission. This virus replicon particle system provides a vital tool to the field and demonstrates utility as a highly efficacious and safe vaccine candidate that can be administered parenterally or mucosally to protect against lethal Nipah disease.
Assuntos
Infecções por Henipavirus , Vírus Nipah , Vacinas Virais , Cricetinae , Humanos , Animais , Camundongos , Infecções por Henipavirus/prevenção & controle , Infecções por Henipavirus/genética , Vacinação , Modelos Animais de Doenças , Vírus Nipah/genética , RepliconRESUMO
Farmed mink are one of few animals in which infection with SARS-CoV-2 has resulted in sustained transmission among a population and spillback from mink to people. In September 2020, mink on a Michigan farm exhibited increased morbidity and mortality rates due to confirmed SARS-CoV-2 infection. We conducted an epidemiologic investigation to identify the source of initial mink exposure, assess the degree of spread within the facility's overall mink population, and evaluate the risk of further viral spread on the farm and in surrounding wildlife habitats. Three farm employees reported symptoms consistent with COVID-19 the same day that increased mortality rates were observed among the mink herd. One of these individuals, and another asymptomatic employee, tested positive for SARS-CoV-2 by real-time reverse transcription PCR (RT-qPCR) 9 days later. All but one mink sampled on the farm were positive for SARS-CoV-2 based on nucleic acid detection from at least one oral, nasal, or rectal swab tested by RT-qPCR (99%). Sequence analysis showed high degrees of similarity between sequences from mink and the two positive farm employees. Epidemiologic and genomic data, including the presence of F486L and N501T mutations believed to arise through mink adaptation, support the hypothesis that the two employees with SARS-CoV-2 nucleic acid detection contracted COVID-19 from mink. However, the specific source of virus introduction onto the farm was not identified. Three companion animals living with mink farm employees and 31 wild animals of six species sampled in the surrounding area were negative for SARS-CoV-2 by RT-qPCR. Results from this investigation support the necessity of a One Health approach to manage the zoonotic spread of SARS-CoV-2 and underscores the critical need for multifaceted public health approaches to prevent the introduction and spread of respiratory viruses on mink farms.
Assuntos
COVID-19 , Ácidos Nucleicos , Humanos , Animais , Michigan/epidemiologia , SARS-CoV-2/genética , Fazendas , Vison , COVID-19/epidemiologia , Genômica , Animais SelvagensRESUMO
Zoonotic transmission of SARS-CoV-2 from infected humans to other animals has been documented around the world, most notably in mink farming operations in Europe and the United States. Outbreaks of SARS-CoV-2 on Utah mink farms began in late July 2020 and resulted in high mink mortality. An investigation of these outbreaks revealed active and past SARS-CoV-2 infections in free-roaming and in feral cats living on or near several mink farms. Cats were captured using live traps, were sampled, fitted with GPS collars, and released on the farms. GPS tracking of these cats show they made frequent visits to mink sheds, moved freely around the affected farms, and visited surrounding residential properties and neighborhoods on multiple occasions, making them potential low risk vectors of additional SARS-CoV-2 spread in local communities.
Assuntos
COVID-19 , SARS-CoV-2 , Gatos , Animais , Humanos , Vison , COVID-19/epidemiologia , COVID-19/veterinária , Fazendas , Utah/epidemiologiaRESUMO
Serosurveillance can provide estimates of population-level exposure to infectious pathogens and has been used extensively during the COVID-19 pandemic. Simultaneous, serological testing for multiple pathogens can be done using bead-based immunoassays to add value to disease-specific serosurveys. We conducted a validation of four SARS-CoV-2 antigens-full-length spike protein, two receptor binding domain proteins, and the nucleocapsid protein-on our existing multiplex bead assay (MBA) for enteric diseases, malaria, and vaccine preventable diseases. After determining the optimal conditions for coupling the antigens to microsphere beads, the sensitivity and specificity of the assay were determined on two instruments (Luminex-200 and MAGPIX) when testing singly (monoplex) versus combined (multiplex). Sensitivity was assessed using plasma from 87 real-time reverse transcription polymerase chain reaction (rRT-PCR) positive persons collected in March-May of 2020 and ranged from 94.3% to 96.6% for the different testing conditions. Specificity was assessed using 98 plasma specimens collected prior to December 2019 and plasma from 19 rRT-PCR negative persons and ranged from 97.4% to 100%. The positive percent agreement was 93.8% to 97.9% using 48 specimens collected > 21 days post-symptom onset, while the negative percent agreement was ≥ 99% for all antigens. Test performance was similar using monoplex or multiplex testing. Integrating SARS-CoV-2 serology with other diseases of public health interest could add significant value to public health programs that have suffered severe programmatic setbacks during the COVID-19 pandemic.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/diagnóstico , COVID-19/epidemiologia , Pandemias , Sensibilidade e Especificidade , ImunoensaioRESUMO
SARS-CoV-2 infection has been described in a wide range of species, including domestic animals such as dogs and cats. Illness in dogs is usually self-limiting, and further diagnostics may not be pursued if clinical signs resolve or they respond to empirical treatment. As new variants emerge, the clinical presentation and role in transmission may vary in animals. This report highlights different clinical presentations and immunological responses in two SARS-CoV-2 Delta-variant-positive dogs with similar exposure to the same fully vaccinated human with a SARS-CoV-2 infection and emphasizes the need for active surveillance and additional One Health research on SARS-CoV-2 variant infections in companion animals and other species.
Assuntos
COVID-19 , Doenças do Cão , Animais , Animais Domésticos , COVID-19/veterinária , Doenças do Gato , Gatos , Doenças do Cão/epidemiologia , Doenças do Cão/prevenção & controle , Cães , Georgia , Humanos , SARS-CoV-2/genéticaRESUMO
Crimean-Congo Hemorrhagic Fever Virus (CCHFV) causes a life-threatening disease with up to a 40% mortality rate. With no approved medical countermeasures, CCHFV is considered a public health priority agent. The non-neutralizing mouse monoclonal antibody (mAb) 13G8 targets CCHFV glycoprotein GP38 and protects mice from lethal CCHFV challenge when administered prophylactically or therapeutically. Here, we reveal the structures of GP38 bound with a human chimeric 13G8 mAb and a newly isolated CC5-17 mAb from a human survivor. These mAbs bind overlapping epitopes with a shifted angle. The broad-spectrum potential of c13G8 and CC5-17 and the practicality of using them against Aigai virus, a closely related nairovirus were examined. Binding studies demonstrate that the presence of non-conserved amino acids in Aigai virus corresponding region prevent CCHFV mAbs from binding Aigai virus GP38. This information, coupled with in vivo efficacy, paves the way for future mAb therapeutics effective against a wide swath of CCHFV strains.
Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia , Camundongos , Humanos , Animais , Vírus da Febre Hemorrágica da Crimeia-Congo/química , Febre Hemorrágica da Crimeia/prevenção & controle , Anticorpos Neutralizantes , Anticorpos Antivirais , Epitopos , Anticorpos MonoclonaisRESUMO
From July−November 2020, mink (Neogale vison) on 12 Utah farms experienced an increase in mortality rates due to confirmed SARS-CoV-2 infection. We conducted epidemiologic investigations on six farms to identify the source of virus introduction, track cross-species transmission, and assess viral evolution. Interviews were conducted and specimens were collected from persons living or working on participating farms and from multiple animal species. Swabs and sera were tested by SARS-CoV-2 real-time reverse transcription polymerase chain reaction (rRT-PCR) and serological assays, respectively. Whole genome sequencing was attempted for specimens with cycle threshold values <30. Evidence of SARS-CoV-2 infection was detected by rRT-PCR or serology in ≥1 person, farmed mink, dog, and/or feral cat on each farm. Sequence analysis showed high similarity between mink and human sequences on corresponding farms. On farms sampled at multiple time points, mink tested rRT-PCR positive up to 16 weeks post-onset of increased mortality. Workers likely introduced SARS-CoV-2 to mink, and mink transmitted SARS-CoV-2 to other animal species; mink-to-human transmission was not identified. Our findings provide critical evidence to support interventions to prevent and manage SARS-CoV-2 in people and animals on mink farms and emphasizes the importance of a One Health approach to address emerging zoonoses.
Assuntos
COVID-19 , Saúde Única , Animais , Humanos , Gatos , Cães , SARS-CoV-2/genética , COVID-19/epidemiologia , COVID-19/veterinária , Vison , Fazendas , Utah/epidemiologiaRESUMO
The evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in the emergence of new variant lineages that have exacerbated the COVID-19 pandemic. Some of those variants were designated as variants of concern/interest (VOC/VOI) by national or international authorities based on many factors including their potential impact on vaccine-mediated protection from disease. To ascertain and rank the risk of VOCs and VOIs, we analyze the ability of 14 variants (614G, Alpha, Beta, Gamma, Delta, Epsilon, Zeta, Eta, Theta, Iota, Kappa, Lambda, Mu, and Omicron) to escape from mRNA vaccine-induced antibodies. The variants show differential reductions in neutralization and replication by post-vaccination sera. Although the Omicron variant (BA.1, BA.1.1, and BA.2) shows the most escape from neutralization, sera collected after a third dose of vaccine (booster sera) retain moderate neutralizing activity against that variant. Therefore, vaccination remains an effective strategy during the COVID-19 pandemic.