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Sudan ebolavirus (SUDV) is a member of the genus Ebolavirus (Family Filoviridae) and has caused sporadic outbreaks of Ebola disease (EBOD), or more specifically Sudan virus disease (SVD), with high mortality rates in Africa. Current vaccines and therapies that have been developed for filoviruses are almost all specific for Ebola virus (EBOV; of the species Zaire ebolavirus), and there is a current lack of therapeutics specific for SUDV. The recent SUDV outbreak in Uganda, which was distributed across multiple districts, including Kampala, a densely populated urban center, highlights the critical need for the development of novel SUDV-specific or pan-Ebola virus therapeutics. Previous work has characterized two monoclonal antibodies, FVM04 and CA45, which have neutralization capabilities against both EBOV and SUDV and have shown protective efficacy in animal challenge studies. Here, we expand upon this work, showing that treatment with a monoclonal antibody cocktail consisting of FVM04 and CA45 provides full protection against lethal SUDV infection in cynomolgus macaques. Studies that evaluate outcomes at late time points after infection, once clinical signs of illness are apparent, are vital for assessing the therapeutic efficacy of antibody therapeutics. We have shown that when treatment is initiated as late as 5 days after infection, with a second dose given on day 8, that treated groups showed few clinical signs or morbidity, with complete survival. This work provides further evidence that FVM04 and CA45 have strong therapeutic potential against SUDV and their development as a pan-Ebola virus therapeutic should be pursued. IMPORTANCE: There are currently no approved vaccines or therapeutics for Sudan virus, a filovirus which is highly related to Ebola virus and causes similar disease and outbreaks. In this study, a cocktail of two potent monoclonal antibodies that effectively neutralize Sudan virus was tested in a nonhuman primate model of Sudan virus disease. Treatment was highly effective, even when initiated as late as 5 days after infection, when clinical signs of infection were already evident. All treated animals showed complete recovery from infection, with little evidence of disease, while all animals that received a control treatment succumbed to infection within 8 days. The study further demonstrated the strong therapeutic potential of the antibody treatment and supported further development for use in Sudan virus outbreaks.
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Anticuerpos Monoclonales , Anticuerpos Antivirales , Ebolavirus , Fiebre Hemorrágica Ebola , Retraso del Tratamiento , Animales , Femenino , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/uso terapéutico , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/uso terapéutico , Modelos Animales de Enfermedad , Ebolavirus/inmunología , Fiebre Hemorrágica Ebola/prevención & control , Fiebre Hemorrágica Ebola/inmunología , Fiebre Hemorrágica Ebola/tratamiento farmacológico , Macaca fascicularis , MasculinoRESUMEN
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged following an outbreak of unexplained viral illness in China in late 2019. Since then, it has spread globally causing a pandemic that has resulted in millions of deaths and has had enormous economic and social consequences. The emergence of SARS-CoV-2 saw the rapid and widespread development of a number of vaccine candidates worldwide, and this never-before-seen pace of vaccine development led to several candidates progressing immediately through clinical trials. Many countries have now approved vaccines for emergency use, with large-scale vaccination programs ongoing. Despite these successes, there remains a need for ongoing pre-clinical and clinical development of vaccine candidates against SARS-CoV-2, as well as vaccines that can elicit strong mucosal immune responses. Here, we report on the efficacy of a Newcastle disease virus-vectored vaccine candidate expressing SARS-CoV-2 spike protein (NDV-FLS) administered to cynomolgus macaques. Macaques given two doses of the vaccine via respiratory immunization developed robust immune responses and had reduced viral RNA levels in nasal swabs and in the lower airway. Our data indicate that NDV-FLS administered mucosally provides significant protection against SARS-CoV-2 infection, resulting in reduced viral burden and disease manifestation, and should be considered as a viable candidate for clinical development.
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Recombinant vesicular stomatitis viruses (rVSVs) engineered to express heterologous viral glycoproteins have proven to be remarkably effective vaccines. Indeed, rVSV-EBOV, which expresses the Ebola virus (EBOV) glycoprotein, recently received clinical approval in the United States and Europe for its ability to prevent EBOV disease. Analogous rVSV vaccines expressing glycoproteins of different human-pathogenic filoviruses have also demonstrated efficacy in pre-clinical evaluations, yet these vaccines have not progressed far beyond research laboratories. In the wake of the most recent outbreak of Sudan virus (SUDV) in Uganda, the need for proven countermeasures was made even more acute. Here we demonstrate that an rVSV-based vaccine expressing the SUDV glycoprotein (rVSV-SUDV) generates a potent humoral immune response that protects guinea pigs from SUDV disease and death. Although the cross-protection generated by rVSV vaccines for different filoviruses is thought to be limited, we wondered whether rVSV-EBOV might also provide protection against SUDV, which is closely related to EBOV. Surprisingly, nearly 60% of guinea pigs that were vaccinated with rVSV-EBOV and challenged with SUDV survived, suggesting that rVSV-EBOV offers limited protection against SUDV, at least in the guinea pig model. These results were confirmed by a back-challenge experiment in which animals that had been vaccinated with rVSV-EBOV and survived EBOV challenge were inoculated with SUDV and survived. Whether these data are applicable to efficacy in humans is unknown, and they should therefore be interpreted cautiously. Nevertheless, this study confirms the potency of the rVSV-SUDV vaccine and highlights the potential for rVSV-EBOV to elicit a cross-protective immune response.
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Ebola virus (EBOV) causes lethal disease in ferrets, whereas Marburg virus (MARV) does not. To investigate this difference, we first evaluated viral entry by infecting ferret spleen cells with vesicular stomatitis viruses pseudotyped with either MARV or EBOV glycoprotein (GP). Both viruses were capable of infecting ferret spleen cells, suggesting that lack of disease is not due to a block in MARV entry. Next, we evaluated replication kinetics of authentic MARV and EBOV in ferret cell lines and demonstrated that, unlike EBOV, MARV was only capable of low levels of replication. Finally, we inoculated ferrets with a recombinant EBOV expressing MARV GP in place of EBOV GP. Infection resulted in uniformly lethal disease within 7-9 days postinfection, while MARV-inoculated animals survived until study endpoint. Together these data suggest that the inability of MARV to cause disease in ferrets is not entirely linked to GP.
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Ebolavirus , Fiebre Hemorrágica Ebola , Enfermedad del Virus de Marburg , Marburgvirus , Animales , Hurones , Línea Celular , Glicoproteínas/genéticaRESUMEN
The global spread of monkeypox virus has raised concerns over the establishment of novel enzootic reservoirs in expanded geographic regions. We demonstrate that although deer mice are permissive to experimental infection with clade I and II monkeypox viruses, the infection is short-lived and has limited capability for active transmission.
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Monkeypox virus , Mpox , Animales , Monkeypox virus/genética , Mpox/epidemiología , Peromyscus , América del Norte/epidemiologíaRESUMEN
Nigeria experiences annual outbreaks of Lassa fever (LF) with high case numbers. At least three clades of Lassa virus (LASV) have been documented in Nigeria, though recent outbreaks are most often associated with clade II or clade III viruses. Using a recently isolated clade III LASV from a case of LF in Nigeria in 2018, we developed and characterized a guinea pig adapted virus capable of causing lethal disease in commercially available Hartley guinea pigs. Uniform lethality was observed after four passages of the virus and was associated with only two dominant genomic changes. The adapted virus was highly virulent with a median lethal dose of 10 median tissue culture infectious doses. Disease was characterized by several hallmarks of LF in similar models including high fever, thrombocytopenia, coagulation disorders, and increased inflammatory immune mediators. High viral loads were noted in all solid organ specimens analyzed. Histological abnormalities were most striking in the lungs and livers of terminal animals and included interstitial inflammation, edema, and steatosis. Overall, this model represents a convenient small animal model for a clade III Nigeria LASV with which evaluation of specific prophylactic vaccines and medical countermeasures can be conducted.
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Fiebre de Lassa , Vacunas Virales , Cobayas , Animales , Virus Lassa , Nigeria/epidemiología , Anticuerpos AntiviralesRESUMEN
Since its emergence in late 2019, the coronavirus disease 2019 (COVID-19) pandemic has caused severe disruption to key aspects of human life globally and highlighted the need for timely, adaptive, and accessible pandemic response strategies. Here, we introduce the cell-free dot blot (CFDB) method, a practical and ultra-low-cost immune diagnostic platform capable of rapid response and mass immunity screening for the current and future pandemics. Similar in mechanism to the widely used enzyme-linked immunosorbent assays (ELISAs), our method is novel and advantageous in that (i) it uses linear DNA to produce the target viral antigen fused to a SpyTag peptide in a cell-free expression system without the need for traditional cloning and antigen purification, (ii) it uses SpyCatcher2-Apex2, an Escherichia coli-produced peroxidase conjugate as a universal secondary detection reagent, obviating the need for commercial or sophisticated enzyme conjugates, and (iii) sera are spotted directly on a nitrocellulose membrane, enabling a simple "dipping" mechanism for downstream incubation and washing steps, as opposed to individual processing of wells in a multiwell plate. To demonstrate the utility of our method, we performed CFDB to detect anti-severe acute respiratory syndrome coronavirus 2 nucleocapsid protein antibodies in precharacterized human sera (23 negative and 36 positive for COVID-19) and hamster sera (16 negative and 36 positive for COVID-19), including independent testing at a collaborating laboratory, and we show assay performance comparable to that of conventional ELISAs. At a similar capacity to 96-well plate ELISA kits, one CFDB assay costs only ~$3 USD. We believe that CFDB can become a valuable pandemic response tool for adaptive and accessible sero-surveillance in human and animal populations. IMPORTANCE The recent COVID-19 pandemic has highlighted the need for diagnostic platforms that are rapidly adaptable, affordable, and accessible globally, especially for low-resource settings. To address this need, we describe the development and functional validation of a novel immunoassay technique termed the cell-free dot blot (CFDB) method. Based on the principles of cell-free synthetic biology and alternative dot blotting procedures, our CFDB immunoassay is designed to provide for timely, practical, and low-cost responses to existing and emerging public health threats, such as the COVID-19 pandemic, at a similar throughput and comparable performance as conventional ELISAs. Notably, the molecular detection reagents used in CFDB can be produced rapidly in-house, using established protocols and basic laboratory infrastructure, minimizing reliance on strained commercial reagents. In addition, the materials and imaging instruments required for CFDB are the same as those used for common Western blotting experiments, further expanding the reach of CFDB in decentralized facilities.
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Filoviruses cause severe hemorrhagic fever with case fatality rates as high as 90%. Filovirus-specific monoclonal antibodies (mAbs) confer protection in nonhuman primates as late as 5 days after challenge, and FDA-approved mAbs REGN-EB3 and mAb114 have demonstrated efficacy against Ebola virus (EBOV) infection in humans. Vectorized antibody expression mediated by adeno-associated virus (AAV) can generate protective and sustained concentrations of therapeutic mAbs in animal models for a variety of infectious diseases, including EBOV. Here we demonstrate that AAV6.2FF-mediated expression of murine IgG2a EBOV mAbs, 2G4 and 5D2, protects from mouse-adapted (MA)-EBOV infection with none of the surviving mice developing anti-VP40 antibodies above background. Protective serum concentrations of AAV6.2FF-2G4/AAV6.2FF-5D2 did not alter endogenous antibody responses to heterologous virus infection. AAV-mediated expression of EBOV mAbs 100 and 114, and pan-ebolavirus mAbs, FVM04, ADI-15878, and CA45, as human IgG1 antibodies conferred protection against MA-EBOV at low serum concentrations, with minimum protective serum levels as low as 2 µg/mL. Vectorized expression of murine IgG2a or human IgG1 mAbs led to sustained expression in the serum of mice for >400 days or for the lifetime of the animal, respectively. AAV6.2FF-mediated mAb expression offers an alternative to recombinant antibody administration in scenarios where long-term protection is preferable to passive immunization.
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Vectored monoclonal antibody (mAb) expression mediated by adeno-associated virus (AAV) gene delivery leads to sustained therapeutic mAb expression and protection against a wide range of infectious diseases in both small and large animal models, including nonhuman primates. Using our rationally engineered AAV6 triple mutant capsid, termed AAV6.2FF, we demonstrate rapid and robust expression of two potent human antibodies against Marburg virus, MR78 and MR191, following intramuscular (IM) administration. IM injection of mice with 1 × 1011 vector genomes (vg) of AAV6.2FF-MR78 and AAV6.2FF-MR191 resulted in serum concentrations of approximately 141 µg/mL and 195 µg/mL of human IgG, respectively, within the first four weeks. Mice receiving 1 × 1011 vg (high) and 1 × 1010 vg (medium) doses of AAV6.2FF-MR191 were completely protected against lethal Marburg virus challenge. No sex-based differences in serum human IgG concentrations were observed; however, administering the AAV-mAb over multiple injection sites significantly increased serum human IgG concentrations. IM administration of three two-week-old lambs with 5 × 1012 vg/kg of AAV6.2FF-MR191 resulted in serum human IgG expression that was sustained for more than 460 days, concomitant with low levels of anti-capsid and anti-drug antibodies. AAV-mAb expression is a viable method for prolonging the therapeutic effect of recombinant mAbs and represents a potential alternative "vaccine" strategy for those with compromised immune systems or in possible outbreak response scenarios.
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We demonstrate that 6 distinct Peromyscus rodent species are permissive to experimental infection with Sin Nombre orthohantavirus (SNV). Viral RNA and SNV antibodies were detected in members of all 6 species. P. leucopus mice demonstrated markedly higher viral and antibody titers than P. maniculatus mice, the established primary hosts for SNV.
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Síndrome Pulmonar por Hantavirus , Enfermedades de los Roedores , Virus Sin Nombre , Animales , Anticuerpos Antivirales , Peromyscus , ARN Viral , Enfermedades de los Roedores/epidemiología , Roedores , Virus Sin Nombre/genéticaRESUMEN
The 1918 H1N1 influenza pandemic was among the most severe in history, taking the lives of approximately 50 million people worldwide, and novel prophylactic vaccines are urgently needed to prevent another pandemic. Given that macaques are physiologically relevant preclinical models of human immunology that have advanced the clinical treatment of infectious diseases, a lethal pandemic influenza challenge model would provide a stringent platform for testing new influenza vaccine concepts. To this end, we infected rhesus macaques and Mauritian cynomolgus macaques with highly pathogenic 1918 H1N1 influenza virus and assessed pathogenesis and disease severity. Despite infection with a high dose of 1918 influenza delivered via multiple routes, rhesus macaques demonstrated minimal signs of disease, with only intermittent viral shedding. Cynomolgus macaques infected via intrabronchial instillation demonstrated mild symptoms, with disease severity depending on the infection dose. Cynomolgus macaques infected with a high dose of 1918 influenza delivered via multiple routes experienced moderate disease characterized by consistent viral shedding, pulmonary infiltrates, and elevated inflammatory cytokine levels. However, 1918 influenza was uniformly nonlethal in these two species, demonstrating that this isolate is insufficiently pathogenic in rhesus and Mauritian cynomolgus macaques to support testing novel prophylactic influenza approaches where protection from severe disease combined with a lethal outcome is desired as a highly stringent indication of vaccine efficacy. IMPORTANCE The world remains at risk of an influenza pandemic, and the development of new therapeutic and preventative modalities is critically important for minimizing human death and suffering during the next influenza pandemic. Animal models are central to the development of new therapies and vaccine approaches. In particular, nonhuman primates like rhesus and cynomolgus macaques are highly relevant preclinical models given their physiological and immunological similarities to humans. Unfortunately, there remains a scarcity of macaque models of pandemic influenza with which to test novel antiviral modalities. Here, we demonstrate that even at the highest doses tested, 1918 influenza was not lethal in these two macaque species, suggesting that they are not ideal for the development and testing of novel pandemic influenza-specific vaccines and therapies. Therefore, other physiologically relevant nonhuman primate models of pandemic influenza are needed.
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Subtipo H1N1 del Virus de la Influenza A , Vacunas contra la Influenza , Gripe Humana , Animales , Humanos , Macaca fascicularis , Macaca mulattaRESUMEN
Increasing cases of SARS-CoV-2 breakthrough infections from immunization with current spike protein-based COVID-19 vaccines highlight the need to develop alternative vaccines using different platforms and/or antigens. In this study, we expressed SARS-CoV-2 spike and nucleocapsid proteins based on a novel vaccinia virus (VACV) ACAM2000 platform (rACAM2000). In this platform, the vaccinia virus host range and immunoregulatory gene E3L was deleted to make the virus attenuated and to enhance innate immune responses, and another host range gene, K3L, was replaced with a poxvirus ortholog gene, taterapox virus 037 (TATV037), to make virus replication competent in both hamster and human cells. Following a single intramuscular immunization, the rACAM2000 coexpressing the spike and nucleocapsid proteins induced significantly improved protection against SARS-CoV-2 challenge in comparison to rACAM2000 expressing the individual proteins in a hamster model, as shown by reduced weight loss and shorter recovery time. The protection was associated with reduced viral loads, increased neutralizing antibody titer, and reduced neutrophil-to-lymphocyte ratio. Thus, our study demonstrates that rACAM2000 expressing a combination of the spike and nucleocapsid antigens is a promising COVID-19 vaccine candidate, and further studies will investigate if the rACAM2000 vaccine candidate can induce a long-lasting immunity against infection by SARS-CoV-2 variants of concern. IMPORTANCE Continuous emergence of SARS-CoV-2 variants which cause breakthrough infection from the immunity induced by current spike protein-based COVID-19 vaccines highlights the need for new generations of vaccines that will induce long-lasting immunity against a wide range of the variants. To this end, we investigated the protective efficacy of the recombinant COVID-19 vaccine candidates based on a novel VACV ACAM2000 platform, in which an immunoregulatory gene, E3L, was deleted and both the SARS-CoV-2 spike (S) and nucleocapsid (N) antigens were expressed. Thus, it is expected that the vaccine candidate we constructed should be more immunogenic and safer. In the initial study described in this work, we demonstrated that the vaccine candidate expressing both the S and N proteins is superior to the constructs expressing an individual protein (S or N) in protecting hamsters against SARS-CoV-2 challenge after a single-dose immunization, and further investigation against different SARS-CoV-2 variants will warrant future clinical evaluations.
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Vacunas contra la COVID-19 , COVID-19 , Glicoproteína de la Espiga del Coronavirus , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , COVID-19/prevención & control , Vacunas contra la COVID-19/genética , Proteínas de la Nucleocápside de Coronavirus , Cricetinae , Humanos , Inmunización , Proteínas de la Nucleocápside/inmunología , Fosfoproteínas , SARS-CoV-2 , Vacuna contra Viruela , Glicoproteína de la Espiga del Coronavirus/inmunología , Virus VacciniaRESUMEN
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the aetiological agent of coronavirus disease 2019 (COVID-19) that has caused a pandemic with millions of human infections. There continues to be a pressing need to develop potential therapies and vaccines to inhibit SARS-CoV-2 infection to mitigate the ongoing pandemic. Epidemiological data from the current pandemic indicates that there may be sex-dependent differences in disease outcomes. To investigate these differences, we proposed to use common small animal species that are frequently used to model disease with viruses. However, common laboratory strains of mice are not readily infected by SARS-CoV-2 because of differences in the angiotensin-converting enzyme 2 (ACE2), the cellular receptor for the virus. To overcome this limitation, we transduced common laboratory accessible strains of mice of different sexes and age groups with a novel a triple AAV6 mutant, termed AAV6.2FF, encoding either human ACE2 or luciferase via intranasal administration to promote expression in the lung and nasal turbinates. Infection of AAV-hACE2-transduced mice with SARS-CoV-2 resulted in high viral titers in the lungs and nasal turbinates, establishment of an IgM and IgG antibody response, and modulation of lung and nasal turbinate cytokine profiles. There were insignificant differences in infection characteristics between age groups and sex-related differences; however, there were significant strain-related differences between BALB/c vs. C57BL/6 mice. We show that AAV-hACE2-transduced mice are a useful for determining immune responses and for potential evaluation of SARS-CoV-2 vaccines and antiviral therapies, and this study serves as a model for the utility of this approach to rapidly develop small-animal models for emerging viruses.
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COVID-19 , SARS-CoV-2 , Animales , Humanos , Ratones , Enzima Convertidora de Angiotensina 2/genética , COVID-19/prevención & control , Vacunas contra la COVID-19 , Dependovirus/genética , Dependovirus/metabolismo , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , SARS-CoV-2/genética , SARS-CoV-2/metabolismoRESUMEN
Many characteristics associated with Ebola virus disease remain to be fully understood. It is known that direct contact with infected bodily fluids is an associated risk factor, but few studies have investigated parameters associated with transmission between individuals, such as the dose of virus required to facilitate spread and route of infection. Therefore, we sought to characterize the impact by route of infection, viremia, and viral shedding through various mucosae, with regards to intraspecies transmission of Ebola virus in a nonhuman primate model. Here, challenge via the esophagus or aerosol to the face did not result in clinical disease, although seroconversion of both challenged and contact animals was observed in the latter. Subsequent intramuscular or intratracheal challenges suggest that viral loads determine transmission likelihood to naive animals in an intramuscular-challenge model, which is greatly facilitated in an intratracheal-challenge model where transmission from challenged to direct contact animal was observed consistently.
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Ebolavirus , Fiebre Hemorrágica Ebola , Animales , Macaca mulatta , Carga Viral , ViremiaRESUMEN
The golden hamster model of SARS-CoV-2 infection recapitulates key characteristics of COVID-19. In this work we examined the influence of the route of exposure, sex, and age on SARS-CoV-2 pathogenesis in hamsters. We report that delivery of SARS-CoV-2 by a low- versus high-volume intranasal or intragastric route results in comparable viral titers in the lung and viral shedding. However, low-volume intranasal exposure results in milder weight loss, whereas intragastric exposure leads to a diminished capacity to regain body weight. Male hamsters, and particularly older male hamsters, display an impaired capacity to recover from illness and delayed viral clearance. These factors were found to influence the nature of the host inflammatory cytokine response but had a minimal effect on the quality and durability of the humoral immune response and susceptibility to re-infection. These data further elucidate key factors that impact pre-clinical challenge studies carried out in the hamster model of COVID-19.
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OBJECTIVE: COVID-19 lockdowns have changed the social and environmental context. Those with ADHD are more vulnerable to experiencing difficulties than their non-ADHD peers. This paper attempts to provide a brief summary of the literature that has emerged during the COVID-19 pandemic. METHOD: A literature search was completed using the following databases; Embase, Ovid Medline, APA PsycInfo. A total of 36 papers were identified as relevant to the topic. RESULTS: The pandemic has exacerbated the core symptoms of ADHD and co-occurring difficulties. Services have adapted their assessment and intervention protocols for tele-health working and findings suggest that tele-interventions present a viable alternative. However, much of this research utilises small sample sizes and a restricted number of population groups. CONCLUSIONS: More research is required to determine the effectiveness of ADHD care during the pandemic and whether adaptations will be retained post-pandemic.
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The pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19). Worldwide efforts are being made to develop vaccines to mitigate this pandemic. We engineered two recombinant Newcastle disease virus (NDV) vectors expressing either the full-length SARS-CoV-2 spike protein (NDV-FLS) or a version with a 19 amino acid deletion at the carboxy terminus (NDV-Δ19S). Hamsters receiving two doses (prime-boost) of NDV-FLS developed a robust SARS-CoV-2-neutralizing antibody response, with elimination of infectious virus in the lungs and minimal lung pathology at five days post-challenge. Single-dose vaccination with NDV-FLS significantly reduced SARS-CoV-2 replication in the lungs but only mildly decreased lung inflammation. NDV-Δ19S-treated hamsters had a moderate decrease in SARS-CoV-2 titers in lungs and presented with severe microscopic lesions, suggesting that truncation of the spike protein was a less effective strategy. In summary, NDV-vectored vaccines represent a viable option for protection against COVID-19.
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Nigeria continues to experience ever increasing annual outbreaks of Lassa fever (LF). The World Health Organization has recently declared Lassa virus (LASV) as a priority pathogen for accelerated research leading to a renewed international effort to develop relevant animal models of disease and effective countermeasures to reduce LF morbidity and mortality in endemic West African countries. A limiting factor in evaluating medical countermeasures against LF is a lack of well characterized animal models outside of those based on infection with LASV strain Josiah originating form Sierra Leone, circa 1976. Here we genetically characterize five recent LASV isolates collected from the 2018 outbreak in Nigeria. Three isolates were further evaluated in vivo and despite being closely related and from the same spatial / geographic region of Nigeria, only one of the three isolates proved lethal in strain 13 guinea pigs and non-human primates (NHP). Additionally, this isolate exhibited atypical pathogenesis characteristics in the NHP model, most notably respiratory failure, not commonly described in hemorrhagic cases of LF. These results suggest that there is considerable phenotypic heterogeneity in LASV infections in Nigeria, which leads to a multitude of pathogenesis characteristics that could account for differences between subclinical and lethal LF infections. Most importantly, the development of disease models using currently circulating LASV strains in West Africa are critical for the evaluation of potential vaccines and medical countermeasures.
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Modelos Animales de Enfermedad , Fiebre de Lassa/genética , Virus Lassa/genética , Animales , Brotes de Enfermedades , Femenino , Cobayas , Humanos , Macaca fascicularis , Masculino , Nigeria , FilogeniaRESUMEN
The use of antibody-based therapies for the treatment of high consequence viral pathogens has gained interest over the last fifteen years. Here, we sought to evaluate the use of unique camelid-based IgG antibodies to prevent lethal hantavirus pulmonary syndrome (HPS) in Syrian hamsters. Using purified, polyclonal IgG antibodies generated in DNA-immunized alpacas, we demonstrate that post-exposure treatments reduced viral burdens and organ-specific pathology associated with lethal HPS. Antibody treated animals did not exhibit signs of disease and were completely protected. The unique structures and properties, particularly the reduced size, distinct paratope formation and increased solubility of camelid antibodies, in combination with this study support further pre-clinical evaluation of heavy-chain only antibodies for treatment of severe respiratory diseases, including HPS.
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Anticuerpos Antivirales/administración & dosificación , Modelos Animales de Enfermedad , Glicoproteínas/inmunología , Infecciones por Hantavirus/prevención & control , Síndrome Pulmonar por Hantavirus/prevención & control , Inmunoglobulina G/administración & dosificación , Orthohantavirus/inmunología , Animales , Anticuerpos Antivirales/inmunología , Camélidos del Nuevo Mundo , Femenino , Infecciones por Hantavirus/inmunología , Infecciones por Hantavirus/virología , Síndrome Pulmonar por Hantavirus/inmunología , Síndrome Pulmonar por Hantavirus/virología , Inmunoglobulina G/inmunología , Masculino , MesocricetusRESUMEN
Widespread circulation of SARS-CoV-2 in humans raises the theoretical risk of reverse zoonosis events with wildlife, reintroductions of SARS-CoV-2 into permissive nondomesticated animals. Here we report that North American deer mice (Peromyscus maniculatus) are susceptible to SARS-CoV-2 infection following intranasal exposure to a human isolate, resulting in viral replication in the upper and lower respiratory tract with little or no signs of disease. Further, shed infectious virus is detectable in nasal washes, oropharyngeal and rectal swabs, and viral RNA is detectable in feces and occasionally urine. We further show that deer mice are capable of transmitting SARS-CoV-2 to naïve deer mice through direct contact. The extent to which these observations may translate to wild deer mouse populations remains unclear, and the risk of reverse zoonosis and/or the potential for the establishment of Peromyscus rodents as a North American reservoir for SARS-CoV-2 remains unknown.