RESUMEN
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in December 20191,2 and is responsible for the coronavirus disease 2019 (COVID-19) pandemic3. Vaccines are an essential countermeasure and are urgently needed to control the pandemic4. Here we show that the adenovirus-vector-based vaccine ChAdOx1 nCoV-19, which encodes the spike protein of SARS-CoV-2, is immunogenic in mice and elicites a robust humoral and cell-mediated response. This response was predominantly mediated by type-1 T helper cells, as demonstrated by the profiling of the IgG subclass and the expression of cytokines. Vaccination with ChAdOx1 nCoV-19 (using either a prime-only or a prime-boost regimen) induced a balanced humoral and cellular immune response of type-1 and type-2 T helper cells in rhesus macaques. We observed a significantly reduced viral load in the bronchoalveolar lavage fluid and lower respiratory tract tissue of vaccinated rhesus macaques that were challenged with SARS-CoV-2 compared with control animals, and no pneumonia was observed in vaccinated SARS-CoV-2-infected animals. However, there was no difference in nasal shedding between vaccinated and control SARS-CoV-2-infected macaques. Notably, we found no evidence of immune-enhanced disease after viral challenge in vaccinated SARS-CoV-2-infected animals. The safety, immunogenicity and efficacy profiles of ChAdOx1 nCoV-19 against symptomatic PCR-positive COVID-19 disease will now be assessed in randomized controlled clinical trials in humans.
Asunto(s)
Betacoronavirus/inmunología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Modelos Animales de Enfermedad , Macaca mulatta , Pandemias/prevención & control , Neumonía Viral/prevención & control , Vacunas Virales/inmunología , Adenoviridae/genética , Animales , Líquido del Lavado Bronquioalveolar , COVID-19 , Vacunas contra la COVID-19 , Infecciones por Coronavirus/genética , Infecciones por Coronavirus/virología , Citocinas/inmunología , Femenino , Inmunidad Celular , Inmunidad Humoral , Inmunoglobulina G/inmunología , Pulmón/inmunología , Pulmón/patología , Pulmón/virología , Macaca mulatta/inmunología , Macaca mulatta/virología , Masculino , Ratones , Neumonía Viral/inmunología , Neumonía Viral/virología , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Células TH1/inmunología , Vacunación , Carga Viral , Vacunas Virales/administración & dosificación , Vacunas Virales/genéticaRESUMEN
Non-human primate models are essential for the development of vaccines and antivirals against infectious diseases. Rhesus macaques are a widely utilized infection model for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We compared cellular tropism and virus replication in rhesus macaques inoculated with SARS-CoV-2 via the intranasal route, or via exposure to aerosols. Intranasal inoculation results in replication in the upper respiratory tract and limited lower respiratory tract involvement, whereas exposure to aerosols results in infection throughout the respiratory tract. In comparison to multi-route inoculation, the intranasal and aerosol inoculation routes result in reduced SARS-CoV-2 replication in the respiratory tract.
RESUMEN
Vesicular stomatitis virus-Ebola virus (VSV-EBOV) vaccine has been successfully used in ring vaccination approaches during EBOV disease outbreaks demonstrating its general benefit in short-term prophylactic vaccination, but actual proof of its benefit in true postexposure prophylaxis (PEP) for humans is missing. Animal studies have indicated PEP efficacy when VSV-EBOV was used within hours of lethal EBOV challenge. Here, we used a lower EBOV challenge dose and a combined intravenous and intramuscular VSV-EBOV administration to improve PEP efficacy in the rhesus macaque model. VSV-EBOV treatment 1 hour after EBOV challenge resulted in delayed disease progression but little benefit in outcome. Thus, we could not confirm previous results indicating questionable benefit of VSV-EBOV for EBOV PEP in a nonhuman primate model.
Asunto(s)
Vacunas contra el Virus del Ébola , Ebolavirus , Fiebre Hemorrágica Ebola , Humanos , Animales , Macaca mulatta , Vesiculovirus , Virus de la Estomatitis Vesicular IndianaRESUMEN
An outbreak of human mpox infection in nonendemic countries appears to have been driven largely by transmission through body fluids or skin-to-skin contact during sexual activity. We evaluated the stability of monkeypox virus (MPXV) in different environments and specific body fluids and tested the effectiveness of decontamination methodologies. MPXV decayed faster at higher temperatures, and rates varied considerably depending on the medium in which virus was suspended, both in solution and on surfaces. More proteinaceous fluids supported greater persistence. Chlorination was an effective decontamination technique, but only at higher concentrations. Wastewater was more difficult to decontaminate than plain deionized water; testing for infectious MPXV could be a helpful addition to PCR-based wastewater surveillance when high levels of viral DNA are detected. Our findings suggest that, because virus stability is sufficient to support environmental MPXV transmission in healthcare settings, exposure and dose-response will be limiting factors for those transmission routes.
Asunto(s)
Líquidos Corporales , Aguas Residuales , Humanos , Monkeypox virus/genética , Monitoreo Epidemiológico Basado en Aguas Residuales , ADN ViralRESUMEN
SARS-CoV-2 transmits principally by air; contact and fomite transmission may also occur. Variants of concern are more transmissible than ancestral SARS-CoV-2. We found indications of possible increased aerosol and surface stability for early variants of concern, but not for the Delta and Omicron variants. Stability changes are unlikely to explain increased transmissibility.
Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Aerosoles y Gotitas RespiratoriasRESUMEN
SARS-CoV-2 emerged in late 2019 and resulted in the ongoing COVID-19 pandemic. Several animal models have been rapidly developed that recapitulate the asymptomatic to moderate disease spectrum. Now, there is a direct need for additional small animal models to study the pathogenesis of severe COVID-19 and for fast-tracked medical countermeasure development. Here, we show that transgenic mice expressing the human SARS-CoV-2 receptor (angiotensin-converting enzyme 2 [hACE2]) under a cytokeratin 18 promoter (K18) are susceptible to SARS-CoV-2 and that infection resulted in a dose-dependent lethal disease course. After inoculation with either 104 TCID50 or 105 TCID50, the SARS-CoV-2 infection resulted in rapid weight loss in both groups and uniform lethality in the 105 TCID50 group. High levels of viral RNA shedding were observed from the upper and lower respiratory tract and intermittent shedding was observed from the intestinal tract. Inoculation with SARS-CoV-2 resulted in upper and lower respiratory tract infection with high infectious virus titers in nasal turbinates, trachea and lungs. The observed interstitial pneumonia and pulmonary pathology, with SARS-CoV-2 replication evident in pneumocytes, were similar to that reported in severe cases of COVID-19. SARS-CoV-2 infection resulted in macrophage and lymphocyte infiltration in the lungs and upregulation of Th1 and proinflammatory cytokines/chemokines. Extrapulmonary replication of SARS-CoV-2 was observed in the cerebral cortex and hippocampus of several animals at 7 DPI but not at 3 DPI. The rapid inflammatory response and observed pathology bears resemblance to COVID-19. Additionally, we demonstrate that a mild disease course can be simulated by low dose infection with 102 TCID50 SARS-CoV-2, resulting in minimal clinical manifestation and near uniform survival. Taken together, these data support future application of this model to studies of pathogenesis and medical countermeasure development.
Asunto(s)
Enzima Convertidora de Angiotensina 2/genética , COVID-19/genética , COVID-19/patología , Queratina-18/genética , Enzima Convertidora de Angiotensina 2/inmunología , Animales , COVID-19/inmunología , COVID-19/virología , Modelos Animales de Enfermedad , Femenino , Humanos , Queratina-18/inmunología , Pulmón/inmunología , Pulmón/patología , Linfocitos/inmunología , Macrófagos/inmunología , Masculino , Ratones , Ratones Transgénicos , Regiones Promotoras Genéticas , SARS-CoV-2/fisiología , Tráquea/inmunología , Tráquea/virologíaRESUMEN
Middle East respiratory syndrome coronavirus (MERS-CoV) infects humans and dromedary camels and is responsible for an ongoing outbreak of severe respiratory illness in humans in the Middle East. Although some mutations found in camel-derived MERS-CoV strains have been characterized, most natural variation found across MERS-CoV isolates remains unstudied. We report on the environmental stability, replication kinetics, and pathogenicity of several diverse isolates of MERS-CoV, as well as isolates of severe acute respiratory syndrome coronavirus 2, to serve as a basis of comparison with other stability studies. Although most MERS-CoV isolates had similar stability and pathogenicity in our experiments, the camel-derived isolate C/KSA/13 had reduced surface stability, and another camel isolate, C/BF/15, had reduced pathogenicity in a small animal model. These results suggest that although betacoronaviruses might have similar environmental stability profiles, individual variation can influence this phenotype, underscoring the need for continual global viral surveillance.
Asunto(s)
COVID-19 , Coronavirus del Síndrome Respiratorio de Oriente Medio , Aerosoles , Animales , Camelus , Humanos , Coronavirus del Síndrome Respiratorio de Oriente Medio/genética , SARS-CoV-2 , Virulencia , ZoonosisRESUMEN
Viruses in the genus Henipavirus encompass 2 highly pathogenic emerging zoonotic pathogens, Hendra virus (HeV) and Nipah virus (NiV). Despite the impact on human health, there is currently limited full-genome sequence information available for henipaviruses. This lack of full-length genomes hampers our ability to understand the molecular drivers of henipavirus emergence. Furthermore, rapidly deployable viral genome sequencing can be an integral part of outbreak response and epidemiological investigations to study transmission chains. In this study, we describe the development of a reverse-transcription, long-range polymerase chain reaction (LRPCR) assay for efficient genome amplification of NiV, HeV, and a related non-pathogenic henipavirus, Cedar virus (CedPV). We then demonstrated the utility of our method by amplifying partial viral genomes from 6 HeV-infected tissue samples from Syrian hamsters and 4 tissue samples from a NiV-infected African green monkey with viral loads as low as 52 genome copies/mg. We subsequently sequenced the amplified genomes on the portable Oxford Nanopore MinION platform and analyzed the data using a newly developed field-deployable bioinformatic pipeline. Our LRPCR assay allows amplification and sequencing of 2 or 4 amplicons in semi-nested reactions. Coupled with an easy-to-use bioinformatics pipeline, this method is particularly useful in the field during outbreaks in resource-poor environments.
Asunto(s)
Henipavirus/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Reacción en Cadena de la Polimerasa/métodos , Genoma Viral , ARN ViralRESUMEN
Nipah virus (NiV) is a bat-borne zoonotic pathogen that can cause severe respiratory distress and encephalitis upon spillover into humans. NiV is capable of infecting a broad range of hosts including humans, pigs, ferrets, dogs, cats, hamsters, and at least 2 genera of bats. Little is known about the biology of NiV in the bat reservoir. In this study, we evaluate the potential for the Egyptian fruit bat (EFB), Rousettus aegyptiacus, to serve as a model organism for studying NiV in bats. Our data suggest that NiV does not efficiently replicate in EFBs in vivo. Furthermore, we show no seroconversion against NiV glycoprotein and a lack of viral replication in primary and immortalized EFB-derived cell lines. Our data show that despite using a conserved target for viral entry, NiV replication is limited in some bat species. We conclude that EFBs are not an appropriate organism to model NiV infection or transmission in bats.
Asunto(s)
Quirópteros/clasificación , Quirópteros/virología , Infecciones por Henipavirus/veterinaria , Virus Nipah/fisiología , Replicación Viral/fisiología , Animales , Infecciones por Henipavirus/virología , Especificidad de la EspecieRESUMEN
We found that environmental conditions affect the stability of severe acute respiratory syndrome coronavirus 2 in nasal mucus and sputum. The virus is more stable at low-temperature and low-humidity conditions, whereas warmer temperature and higher humidity shortened half-life. Although infectious virus was undetectable after 48 hours, viral RNA remained detectable for 7 days.
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Betacoronavirus/genética , Infecciones por Coronavirus/virología , Moco/virología , Neumonía Viral/virología , ARN Viral/análisis , Esputo/virología , COVID-19 , Calor , Humanos , Humedad , Cavidad Nasal/virología , Pandemias , Estabilidad del ARN , SARS-CoV-2RESUMEN
The coronavirus pandemic has created worldwide shortages of N95 respirators. We analyzed 4 decontamination methods for effectiveness in deactivating severe acute respiratory syndrome coronavirus 2 virus and effect on respirator function. Our results indicate that N95 respirators can be decontaminated and reused, but the integrity of respirator fit and seal must be maintained.
Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/prevención & control , Descontaminación/métodos , Equipo Reutilizado , Pandemias/prevención & control , Neumonía Viral/prevención & control , Ventiladores Mecánicos/virología , COVID-19 , Infecciones por Coronavirus/virología , Humanos , Neumonía Viral/virología , SARS-CoV-2RESUMEN
After the 2017 Ebola virus (EBOV) outbreak in Likati, a district in northern Democratic Republic of the Congo, we sampled small mammals from the location where the primary case-patient presumably acquired the infection. None tested positive for EBOV RNA or antibodies against EBOV, highlighting the ongoing challenge in detecting animal reservoirs for EBOV.
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Ebolavirus , Fiebre Hemorrágica Ebola , Animales , Animales Salvajes , República Democrática del Congo/epidemiología , Brotes de Enfermedades , Ebolavirus/genética , Fiebre Hemorrágica Ebola/epidemiología , HumanosRESUMEN
Sequencing viral genomes during an outbreak can facilitate response and containment efforts. In this study, we describe a reverse transcription long-range polymerase chain reaction for efficient amplification and sequencing of the Ebola virus (EBOV) genome in 2 seminested reactions. We demonstrate that our method remains robust with complex biological samples by amplifying and sequencing the EBOV genome from EBOV-infected nonhuman primates (NHPs). We further demonstrate that we are able to recover viral genomes from starting concentrations as low as 103 50% tissue culture infective dose (TCID50)/mL, suggesting that this method can be employed to sequence EBOV genomes from ecologically or clinically derived samples.
Asunto(s)
Ebolavirus/genética , Genoma Viral/genética , Fiebre Hemorrágica Ebola/virología , Reacción en Cadena de la Polimerasa/métodos , Animales , Brotes de Enfermedades , Humanos , Macaca fascicularis/virología , Análisis de Secuencia de ARN/métodosRESUMEN
Diagnostics and research analyses involving samples containing maximum-containment viruses present unique challenges, and inactivation protocols compatible with downstream testing are needed. Our aim was to identify a validated viral inactivation protocol compatible with bacterial identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We assessed a panel of bacteria with 6 validated maximum-containment virus-inactivation protocols and report that inactivation with TRIzol or γ-irradiation is compatible with MALDI-TOF MS. The availability, simplicity, and rapidity of TRIzol inactivation make this method the more suitable choice.
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Bacterias/efectos de la radiación , Coinfección/virología , Inactivación de Virus/efectos de la radiación , Virus/efectos de la radiación , Humanos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodosRESUMEN
Background: The 1918 Spanish H1N1 influenza pandemic was the most severe recorded influenza pandemic with an estimated 20-50 million deaths worldwide. Even though it is known that influenza viruses can cause extrarespiratory tract complications-which are often severe or even fatal-the potential contribution of extrarespiratory tissues to the pathogenesis of 1918 H1N1 virus infection has not been studied comprehensively. Methods: Here, we performed a time-course study in ferrets inoculated intranasally with 1918 H1N1 influenza virus, with special emphasis on the involvement of extrarespiratory tissues. Respiratory and extrarespiratory tissues were collected after inoculation for virological, histological, and immunological analysis. Results: Infectious virus was detected at high titers in respiratory tissues and, at lower titers in most extrarespiratory tissues. Evidence for active virus replication, as indicated by the detection of nucleoprotein by immunohistochemistry, was observed in the respiratory tract, peripheral and central nervous system, and liver. Proinflammatory cytokines were up-regulated in respiratory tissues, olfactory bulb, spinal cord, liver, heart, and pancreas. Conclusions: 1918 H1N1 virus spread to and induced cytokine responses in tissues outside the respiratory tract, which likely contributed to the severity of infection. Moreover, our data support the suggested link between 1918 H1N1 infection and central nervous system disease.
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Citocinas/metabolismo , Subtipo H1N1 del Virus de la Influenza A/inmunología , Infecciones por Orthomyxoviridae/virología , Replicación Viral/fisiología , Animales , Citocinas/genética , Hurones , Regulación de la Expresión Génica , Humanos , Inflamación/metabolismo , Pulmón/patología , Infecciones por Orthomyxoviridae/patología , Enfermedades Respiratorias/virología , Distribución Tisular , Pérdida de PesoAsunto(s)
Betacoronavirus/fisiología , Infecciones por Coronavirus/transmisión , Viabilidad Microbiana , Neumonía Viral/transmisión , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/fisiología , Aerosoles , Teorema de Bayes , Betacoronavirus/patogenicidad , COVID-19 , Semivida , Humanos , Pandemias , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/patogenicidad , SARS-CoV-2RESUMEN
We tested the suitability of the domestic pig as a model for Middle East respiratory syndrome coronavirus (MERS-CoV) infection. Inoculation did not cause disease, but a low level of virus replication, shedding, and seroconversion were observed. Pigs do not recapitulate human MERS-CoV and are unlikely to constitute a reservoir in nature.
Asunto(s)
Infecciones por Coronavirus/veterinaria , Reservorios de Enfermedades/veterinaria , Coronavirus del Síndrome Respiratorio de Oriente Medio/fisiología , Enfermedades de los Porcinos/virología , Animales , Infecciones por Coronavirus/virología , Reservorios de Enfermedades/virología , Especificidad del Huésped , PorcinosRESUMEN
The largest outbreak of Ebola virus disease began in Guéckédou, Guinea, West Africa, in December 2013 and rapidly spread to major population centers in 3 West African countries. Early reports in some scientific and public media speculated that the virus had evolved to more effectively transmit between humans. One route of transmission postulated was aerosol transmission, although there was little epidemiological evidence to support this claim. This study investigates the viability of 2 Zaire ebolavirus strains within aerosols at 22°C and 80% relative humidity over time. The results presented here indicate that there is no difference in virus stability between the 2 strains and that viable virus can be recovered from an aerosol 180 minutes after it is generated.
Asunto(s)
Brotes de Enfermedades , Ebolavirus/fisiología , Fiebre Hemorrágica Ebola/virología , Aerosoles , África Occidental/epidemiología , República Democrática del Congo/epidemiología , Guinea/epidemiología , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Viabilidad Microbiana , Especificidad de la EspecieRESUMEN
The development of point-of-care clinical chemistry analyzers has enabled the implementation of these ancillary tests in field laboratories in resource-limited outbreak areas. The Eternal Love Winning Africa (ELWA) outbreak diagnostic laboratory, established in Monrovia, Liberia, to provide Ebola virus and Plasmodium spp. diagnostics during the Ebola epidemic, implemented clinical chemistry analyzers in December 2014. Clinical chemistry testing was performed for 68 patients in triage, including 12 patients infected with Ebola virus and 18 infected with Plasmodium spp. The main distinguishing feature in clinical chemistry of Ebola virus-infected patients was the elevation in alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and γ-glutamyltransferase levels and the decrease in calcium. The implementation of clinical chemistry is probably most helpful when the medical supportive care implemented at the Ebola treatment unit allows for correction of biochemistry derangements and on-site clinical chemistry analyzers can be used to monitor electrolyte balance.