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Accurate and timely testing for SARS-CoV-2 in the pediatric population is crucial to control the COVID-19 pandemic; saliva testing has been proposed as a less invasive alternative to nasopharyngeal swabs. We sought to compare the detection of SARS-CoV-2 using saliva versus nasopharyngeal swab in the pediatric population, and to determine the optimum time of testing for SARS-CoV-2 using saliva.We conducted a longitudinal diagnostic study in Ottawa, Canada, from Jan. 19 to Mar. 26, 2021. Children aged 3-17 years were eligible if they exhibited symptoms of COVID-19, had been identified as a high-risk or close contact to someone confirmed positive for SARS-CoV-2 or had travelled outside Canada in the previous 14 days. Participants provided both nasopharyngeal swab and saliva samples. Saliva was collected using a self-collection kit (DNA Genotek, OM-505) or a sponge-based kit (DNA Genotek, ORE-100) if they could not provide a saliva sample into a tube.Among 1580 paired nasopharyngeal and saliva tests, 60 paired samples were positive for SARS-CoV-2. Forty-four (73.3%) were concordant-positive results and 16 (26.6%) were discordant, among which 8 were positive only on nasopharyngeal swab and 8 were positive only on saliva testing. The sensitivity of saliva was 84.6% (95% confidence interval 71.9%-93.1%).Salivary testing for SARS-CoV-2 in the pediatric population is less invasive and shows similar detection of SARS-CoV-2 to nasopharyngeal swabs. It may therefore provide a feasible alternative for diagnosis of SARS-CoV-2 infection in children.

Neutralization assays are important in understanding and quantifying neutralizing antibody responses towards SARS-CoV-2. The SARS-CoV-2 Lentivirus Surrogate Neutralization Assay (SCLSNA) can be used in biosafety level 2 (BSL-2) laboratories and has been shown to be a reliable, alternative approach to the plaque reduction neutralization test (PRNT). In this study, we optimized and validated the SCLSNA to assess its ability as a comparator and pre-screening method to support the PRNT. Comparability between the PRNT and SCLSNA was determined through clinical sensitivity and specificity evaluations. Clinical sensitivity and specificity produced acceptable results with 100% (95% CI: 94-100) specificity and 100% (95% CI: 94-100) sensitivity against ancestral Wuhan spike pseudotyped lentivirus. The sensitivity and specificity against B.1.1.7 spike pseudotyped lentivirus resulted in 88.3% (95% CI: 77.8 to 94.2) and 100% (95% CI: 94-100), respectively. Assay precision measuring intra-assay variability produced acceptable results for High (1:≥ 640 PRNT50), Mid (1:160 PRNT50) and Low (1:40 PRNT50) antibody titer concentration ranges based on the PRNT50, with %CV of 14.21, 12.47, and 13.28 respectively. Intermediate precision indicated acceptable ranges for the High and Mid concentrations, with %CV of 15.52 and 16.09, respectively. However, the Low concentration did not meet the acceptance criteria with a %CV of 26.42. Acceptable ranges were found in the robustness evaluation for both intra-assay and inter-assay variability. In summary, the validation parameters tested met the acceptance criteria, making the SCLSNA method fit for its intended purpose, which can be used to support the PRNT.

SARS-CoV-2 virus spike (S) protein is an envelope protein responsible for binding to the ACE2 receptor, driving subsequent entry into host cells. The existence of multiple disulfide bonds in the S protein makes it potentially susceptible to reductive cleavage. Using a tri-part split luciferase-based binding assay, we evaluated the impacts of chemical reduction on S proteins from different virus variants and found that those from the Omicron family are highly vulnerable to reduction. Through manipulation of different Omicron mutations, we found that alterations in the receptor binding module (RBM) are the major determinants of this vulnerability. Specifically we discovered that Omicron mutations facilitate the cleavage of C480-C488 and C379-C432 disulfides, which consequently impairs binding activity and protein stability. The vulnerability of Omicron S proteins suggests a mechanism that can be harnessed to treat specific SARS-CoV-2 strains.

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.

Background Reverse-transcription polymerase chain reaction (RT-PCR) has become the primary method to diagnose viral diseases, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). RT-PCR detects RNA, not infectious virus; thus, its ability to determine duration of infectivity of patients is limited. Infectivity is a critical determinant in informing public health guidelines/interventions. Our goal was to determine the relationship between E gene SARS-CoV-2 RT-PCR cycle threshold (Ct) values from respiratory samples, symptom onset to test (STT), and infectivity in cell culture. Methods In this retrospective cross-sectional study, we took SARS-CoV-2 RT-PCR–confirmed positive samples and determined their ability to infect Vero cell lines. Results Ninety RT-PCR SARS-CoV-2–positive samples were incubated on Vero cells. Twenty-six samples (28.9%) demonstrated viral growth. Median tissue culture infectious dose/mL was 1780 (interquartile range, 282–8511). There was no growth in samples with a Ct > 24 or STT > 8 days. Multivariate logistic regression using positive viral culture as a binary predictor variable, STT, and Ct demonstrated an odds ratio (OR) for positive viral culture of 0.64 (95% confidence interval [CI], .49–.84; P 24. Conclusions SARS-CoV-2 Vero cell infectivity was only observed for RT-PCR Ct 24 and duration of symptoms > 8 days may be low. This information can inform public health policy and guide clinical, infection control, and occupational health decisions. Further studies of larger size are needed.

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., Deer mice are natural hosts for a number of human pathogens. Here, Griffin et al. report that intranasal exposure of the North American deer mouse to SARS-CoV-2 results in virus replication and shedding, despite causing only mild or asymptomatic illness. Additionally, infected deer mice can transmit SARS-CoV-2 to naïve deer mice.

The emergence of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the resultant pandemic of coronavirus disease 2019 (COVID-19) has led to over one hundred million confirmed infections, greater than three million deaths, and severe economic and social disruption. Animal models of SARS-CoV-2 are critical tools for the pre-clinical evaluation of antivirals, vaccines, and candidate therapeutics currently under urgent development to curb COVID-19-associated morbidity and mortality. The golden (Syrian) hamster model of SARS-CoV-2 infection recapitulates key characteristics of severe COVID-19, including high-titer viral replication in the upper and lower respiratory tract and the development of pathogenic lesions in the lungs. In this work we examined the influence of the route of exposure, sex, and age on SARS-CoV-2 pathogenesis in golden hamsters. We report that delivery of SARS-CoV-2 primarily to the nasal passages (low-volume intranasal), the upper and lower respiratory tract (high-volume intranasal), or the digestive tract (intragastric) results in comparable viral titers in the lung tissue and similar levels of viral shedding during acute infection. However, low-volume intranasal exposure results in milder weight loss during acute infection while intragastric exposure leads to a diminished capacity to regain body weight following the period of acute illness. Further, we examined both sex and age differences in response to SARS-CoV-2 infection. Male hamsters, and to a greater extent older male hamsters, display an impaired capacity to recover from illness and a delay in viral clearance compared to females. Lastly, route of exposure, sex, and age were found to influence the nature of the host inflammatory cytokine response, but they had a minimal effect on both the quality and durability of the humoral immune response as well as the susceptibility of hamsters to SARS-CoV-2 re-infection. Together, these data indicate that the route of exposure, sex, and age have a meaningful impact SARS-CoV-2 pathogenesis in hamsters and that these variables should be considered when designing pre-clinical challenge studies.

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.

The zoonotic spillover of the pandemic SARS-coronavirus 2 (SARS-CoV-2) from an animal reservoir, currently presumed to be the Chinese horseshoe bat, into a naïve human population has rapidly resulted in a significant global public health emergency. Worldwide circulation of SARS-CoV-2 in humans raises the theoretical risk of reverse zoonosis events with wildlife, reintroductions of SARS-CoV-2 into permissive non-domesticated animals, potentially seeding new host reservoir species and geographic regions in which bat SARS-like coronaviruses have not historically been endemic. Here we report that North American deer mice (Peromyscus maniculatus) and some closely related members of theCricetidaefamily of rodents possess key amino acid residues within the angiotensin-converting enzyme 2 (ACE2) receptor known to confer SARS-CoV-2 spike protein binding.Peromyscusrodent species are widely distributed across North America and are the primary host reservoirs of several emerging pathogens that repeatedly spill over into humans includingBorrelia burgdorferi, the causative agent of Lyme disease, deer tick virus, and Sin Nombre orthohantavirus, the causative agent of hantavirus pulmonary syndrome (HPS). We demonstrate that adult deer mice 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 ofPeromyscusrodents as a North American reservoir for SARS-CoV-2 is unknown. Nevertheless, efforts to monitor wild, peri-domesticPeromyscusrodent populations are likely warranted as the SARS-CoV-2 pandemic progresses.

Background There remains an important need for prophylactic anti-Ebola virus vaccine candidates that elicit long-lasting immune responses and can be delivered to vulnerable populations that are unable to receive live-attenuated or viral vector vaccines. Methods We designed novel synthetic anti-Ebola virus glycoprotein (EBOV-GP) DNA vaccines as a strategy to expand protective breadth against diverse EBOV strains and evaluated the impact of vaccine dosing and route of administration on protection against lethal EBOV-Makona challenge in cynomolgus macaques. Long-term immunogenicity was monitored in nonhuman primates for >1 year, followed by a 12-month boost. Results Multiple-injection regimens of the EBOV-GP DNA vaccine, delivered by intramuscular administration followed by electroporation, were 100% protective against lethal EBOV-Makona challenge. Impressively, 2 injections of a simple, more tolerable, and dose-sparing intradermal administration followed by electroporation generated strong immunogenicity and was 100% protective against lethal challenge. In parallel, we observed that EBOV-GP DNA vaccination induced long-term immune responses in macaques that were detectable for at least 1 year after final vaccination and generated a strong recall response after the final boost. Conclusions These data support that this simple intradermal-administered, serology-independent approach is likely important for additional study towards the goal of induction of anti-EBOV immunity in multiple at-risk populations.

Antimicrobial resistance (AMR) is a top priority for several national and international organizations, including the World Health Organization (WHO), the European Centre for Disease Prevention and Control (ECDC), the National Institutes of Health (NIH), and the Centers for Disease Control and Prevention (CDC). All the initiatives describe a multifaceted approach involving multiple disciplines to combat this problem. A part of this approach is to gain an understanding of what genes are responsible for antimicrobial resistance and how we can use this knowledge to develop rapid diagnostic assays and new antimicrobial agents. Here, we describe the current knowledge of the genetic markers that confer resistance in Gram-negative organisms and provide some insights into how this knowledge can be used in the ongoing battle against antimicrobial resistance.

BackgroundThere are currently limited data for the use of specific antiviral therapies for the treatment of Ebola virus disease (EVD). While there is anecdotal evidence that supportive care may be effective, there is a paucity of direct experimental data to demonstrate a role for supportive care in EVD. We studied the impact of ICU-level supportive care interventions including fluid resuscitation, vasoactive medications, blood transfusion, hydrocortisone, and ventilator support on the pathophysiology of EVD in rhesus macaques infected with a universally lethal dose of Ebola virus strain Makona C07.MethodsFour NHPs were infected with a universally lethal dose Ebola virus strain Makona, in accordance with the gold standard lethal Ebola NHP challenge model. Following infection, the following therapeutic interventions were employed: continuous bedside supportive care, ventilator support, judicious fluid resuscitation, vasoactive medications, blood transfusion, and hydrocortisone as needed to treat cardiovascular compromise. A range of physiological parameters were continuously monitored to gage any response to the interventions.ResultsAll four NHPs developed EVD and demonstrated a similar clinical course. All animals reached a terminal endpoint, which occurred at an average time of 166.5 ± 14.8 h post-infection. Fluid administration may have temporarily blunted a rise in lactate, but the effect was short lived. Vasoactive medications resulted in short-lived improvements in mean arterial pressure. Blood transfusion and hydrocortisone did not appear to have a significant positive impact on the course of the disease.ConclusionsThe model employed for this study is reflective of an intramuscular infection in humans (e.g., needle stick) and is highly lethal to NHPs. Using this model, we found that the animals developed progressive severe organ dysfunction and profound shock preceding death. While the overall impact of supportive care on the observed pathophysiology was limited, we did observe some time-dependent positive responses. Since this model is highly lethal, it does not reflect the full spectrum of human EVD. Our findings support the need for continued development of animal models that replicate the spectrum of human disease as well as ongoing development of anti-Ebola therapies to complement supportive care.

Ebola virus (EBOV) outbreaks can claim numerous lives and also devastate the local health infrastructure, as well as the economy, of affected countries. Lethal EBOV infection has been documented to decrease the levels of several immune cells in the blood that are necessary to defend the host. This decrease in immune cells is, however, not observed in individuals who survive EBOV infection. Having a better grasp of how these immune cells are lost is therefore of high importance to develop and improve new and existing therapeutics. The significance of our research is in identifying the mechanism responsible for the apparent loss of immune cells in lethal EBOV infection. This will allow therapeutic options aimed at preventing the loss of these immune cells, therefore allowing infected individuals to better fight the infection., Understanding the immune parameters responsible for survival following Ebola virus (EBOV) infection is paramount for developing countermeasures. In lethal EBOV infections, levels of both NK and T cells decline drastically in the circulation and lymphoid tissues before death. However, the fate of these lymphocytes in viral replication sites remains unknown. In this study, reverse transcription-PCR (RT-PCR) and fluorescence-activated cell sorting (FACS) analysis were used to investigate lymphocyte frequencies in various infected mouse tissues after challenge with mouse-adapted EBOV (MA-EBOV). A decrease in NK cell numbers from systemic circulation was observed concomitant to an increase of these cells in tissues that are supporting active replication of EBOV. Unexpectedly, NK accumulation in virus replication sites correlated with enhanced EBOV disease progression in specific conditions; at a high challenge dose, NK-depleted mice displayed lower viremia and liver damage and higher hepatic T cell levels. Upregulation of UL16 binding protein 1 (ULBP-1) was detected in hepatic T cells, suggesting that NK cells participate in their elimination. Overall, this study supports the concept that NK cells accumulate in EBOV-infected tissues and can contribute to viral pathogenicity. IMPORTANCE Ebola virus (EBOV) outbreaks can claim numerous lives and also devastate the local health infrastructure, as well as the economy, of affected countries. Lethal EBOV infection has been documented to decrease the levels of several immune cells in the blood that are necessary to defend the host. This decrease in immune cells is, however, not observed in individuals who survive EBOV infection. Having a better grasp of how these immune cells are lost is therefore of high importance to develop and improve new and existing therapeutics. The significance of our research is in identifying the mechanism responsible for the apparent loss of immune cells in lethal EBOV infection. This will allow therapeutic options aimed at preventing the loss of these immune cells, therefore allowing infected individuals to better fight the infection.

Background: The 2014–2016 Ebola outbreak in West Africa recapitulated that nosocomial spread of Ebola virus could occur and that health care workers were at particular risk including notable cases in Europe and North America. These instances highlighted the need for centers to better prepare for potential Ebola virus cases, including understanding how the virus spreads and which interventions pose the greatest risk. Methods: We created a fully equipped intensive care unit (ICU), within a Biosafety Level 4 (BSL4) laboratory, and infected multiple sedated non-human primates (NHPs) with Ebola virus. While providing bedside care, we sampled blood, urine, and gastric residuals, as well as buccal, ocular, nasal, rectal, and skin swabs, to assess the risks associated with routine care. We also assessed the physical environment at end-point. Results: Although viral RNA was detectable in blood as early as three days post-infection, it was not detectable in the urine, gastric fluid, or swabs until late-stage disease. While droplet spread and fomite contamination were present on a few of the surfaces that were routinely touched while providing care in the ICU for the infected animal, these may have been abrogated through good routine hygiene practices. Conclusions: Overall this study has helped further our understanding of which procedures may pose the highest risk to healthcare providers and provides temporal evidence of this over the clinical course of disease.

Highlights • High demand for diagnostic testing for COVID-19 has depleted commercially available consumables for diagnostic testing. • Alternative swabs that are not approved for Nasopharyngeal sampling work well for COVID-19 diagnostics. • Alternative fluids that are readily available in hospital settings can function as alternatives to Viral Transport Media. • No meaningful difference in viral yield from different swabs and most transport mediums for the collection and detection of SARS-CoV-2, indicating swab and medium alternatives could be used if supplies run out., On March 11, 2020, the World Health Organization (WHO) assessed COVID-19, caused by SARS-CoV-2, as a pandemic. As of June 1, 2020, SARS-CoV-2 has had a documented effect of over 6 million cases world-wide, amounting to over 370,000 deaths (World Health Organization, 2020. Novel Coronavirus (COVID-19) Situation. http://https://covid19.who.int/). Consequently, the high demand for testing has resulted in a depletion of commercially available consumables, including the recommended swabs and viral transport media (VTM) required for nasopharyngeal sampling. Therefore, the potential use of unvalidated alternatives must be explored to address the global shortage of testing supplies. To tackle this issue, we evaluated the utility of different swabs and transport mediums for the molecular detection of SARS-CoV-2. This study compared the performance of six swabs commonly found in primary and tertiary health care settings (PurFlock Ultra, FLOQSwab, Puritan Pur-Wraps cotton tipped applicators, Puritan polyester tipped applicators, MedPro 6” cotton tipped applicators, and HOLOGIC Aptima) for their efficacy in testing for SARS-CoV-2. Separately, the molecular detection of SARS-CoV-2 was completed from different transport mediums (DMEM, PBS, 100 % ethanol, 0.9 % normal saline and VTM), which were kept up to three days at room temperature (RT). The results indicate that there is no meaningful difference in viral yield from different swabs and most transport mediums for the collection and detection of SARS-CoV-2, indicating swab and medium alternatives could be used if supplies run out.

Introduction: There are currently no licensed treatments for Ebola Virus Disease, making supportive care the only viable option. While there is anecdotal evidence that this is effective, the paucity of experimental data to demonstrate the role of supportive care in EVD has limited its use. We hypothesized that supportive care would enhance survival in a non-human primate (NHP) model of EVD. Methods: Three NHPs were infected with Ebola virus strain Makona and provided continuous bedside supportive care, including ventilatory support, fluid resuscitation, vasoactive medications, blood transfusion and hydrocortisone as needed to treat cardiovascular compromise. Findings: All three NHPs developed EVD and demonstrated a very similar clinical course and ultimately reached a terminal endpoint at an average time of 160 ± 8·7 hours post infection, which is similar to caged animals (144-192 hours). Fluid administration may have temporarily blunted a rise in lactate but the effect was short lived. Vasoactive medications, blood transfusion and hydrocortisone did not appear to have an impact. Interpretation: Supportive care did not impact survival length in a high stringency NHP EVD disease model. Our findings help support the need for the development and use of specific anti-Ebola therapies. Funding Statement: Funding was provided by the Canadian Institutes of Health Research and the Government of Canada. Declaration of Interests: None of the authors had a conflict of interest with regard to this study. Ethics Approval Statement: The study protocol was reviewed and approved by the institutional Animal Care Committee, in accordance with Canadian Council on Animal Care (CCAC) guidelines.

G(M2) gangliosidoses are severe neurodegenerative disorders resulting from a deficiency in β-hexosaminidase A activity and lacking effective therapies. Using a Sandhoff disease (SD) mouse model (Hexb(-/-)) of the G(M2) gangliosidoses, we tested the potential of systemically delivered adeno-associated virus 9 (AAV9) expressing Hexb cDNA to correct the neurological phenotype. Neonatal or adult SD and normal mice were intravenously injected with AAV9-HexB or -LacZ and monitored for serum β-hexosaminidase activity, motor function, and survival. Brain G(M2) ganglioside, β-hexosaminidase activity, and inflammation were assessed at experimental week 43, or an earlier humane end point. SD mice injected with AAV9-LacZ died by 17 weeks of age, whereas all neonatal AAV9-HexB-treated SD mice survived until 43 weeks (P0.0001) with only three exhibiting neurological dysfunction. SD mice treated as adults with AAV9-HexB died between 17 and 35 weeks. Neonatal SD-HexB-treated mice had a significant increase in brain β-hexosaminidase activity, and a reduction in G(M2) ganglioside storage and neuroinflammation compared to adult SD-HexB- and SD-LacZ-treated groups. However, at 43 weeks, 8 of 10 neonatal-HexB injected control and SD mice exhibited liver or lung tumors. This study demonstrates the potential for long-term correction of SD and other G(M2) gangliosidoses through early rAAV9 based systemic gene therapy.

Zika virus (ZIKV) is an emerging pathogen causally associated with serious sequelae in fetuses, inducing fetal microcephaly and other neurodevelopment defects. ZIKV is primarily transmitted by mosquitoes, but can persist in human semen and sperm, and sexual transmission has been documented. Moreover, exposure of type-I interferon knockout mice to ZIKV results in severe damage to the testes, epididymis and sperm. Candidate ZIKV vaccines have shown protective efficacy in preclinical studies carried out in animal models, and several vaccines have entered clinical trials. Here, we report that administration of a synthetic DNA vaccine encoding ZIKV pre-membrane and envelope (prME) completely protects mice against ZIKV-associated damage to the testes and sperm and prevents viral persistence in the testes following challenge with a contemporary strain of ZIKV. These data suggest that DNA vaccination merits further investigation as a potential means to reduce ZIKV persistence in the male reproductive tract., Zika virus (ZIKV) can persist in human semen and sperm, which can result in sexual transmission. Here, Griffin et al. show that a DNA vaccine, expressing ZIKV pre-membrane and envelope proteins, protects mice from infection-associated damage to testes and sperm, and prevents viral persistence in testes.

Critical care needs have been rising in recent decades as populations age and comorbidities increase. Sepsis-related admissions to critical care contribute up to 50% of volume and septic shock carries a 35–54% fatality rate. Improvements in sepsis-related care and mortality would have a significant impact of a resource-intensive area of health care delivery. Unfortunately, research has been hampered by the lack of an animal model that replicates the complex care provided to humans in an intensive care unit (ICU). We developed a protocol to provide full ICU type supportive care to Rhesus macaques. This included mechanical ventilation, continuous sedation, fluid and electrolyte management and vasopressor support in response to Ebolavirus-induced septic shock. The animals accurately recapitulated human responses to a full range of ICU interventions (e.g. fluid resuscitation). This model can overcome current animal model limitations by accurately emulating the complexity of ICU care and thereby provide a platform for testing new interventions in critical care and sepsis without placing patients at risk.

As the Ebola outbreak in West Africa continues and cases appear in the United States and other countries, the need for long-lasting vaccines to preserve global health is imminent. Here, we evaluate the long-term efficacy of a respiratory and sublingual (SL) adenovirus-based vaccine in non-human primates in two phases. In the first, a single respiratory dose of 1.4×10(9) infectious virus particles (ivp)/kg of Ad-CAGoptZGP induced strong Ebola glycoprotein (GP) specific CD8+ and CD4+ T cell responses and Ebola GP-specific antibodies in systemic and mucosal compartments and was partially (67%) protective from challenge 62 days after immunization. The same dose given by the SL route induced Ebola GP-specific CD8+ T cell responses similar to that of intramuscular (IM) injection, however, the Ebola GP-specific antibody response was low. All primates succumbed to infection. Three primates were then given the vaccine in a formulation that improved the immune response to Ebola in rodents. Three primates were immunized with 2.0×10(10) ivp/kg of vaccine by the SL route. Diverse populations of polyfunctional Ebola GP-specific CD4+ and CD8+ T cells and significant anti-Ebola GP antibodies were present in samples collected 150 days after respiratory immunization. The formulated vaccine was fully protective against challenge 21 weeks after immunization. While diverse populations of Ebola GP-specific CD4+ T cells were produced after SL immunization, antibodies were not neutralizing and the vaccine was unprotective. To our knowledge, this is the first time that durable protection from a single dose respiratory adenovirus-based Ebola vaccine has been demonstrated in primates.

Enhanced virulence and/or transmission of West African Ebola virus (EBOV) variants, which are divergent from their Central African counterparts, are suspected to have contributed to the sizable toll of the recent Ebola virus disease (EVD) outbreak. This study evaluated the pathogenicity and shedding in rhesus macaques infected with 1 of 2 West African isolates (EBOV-C05 or EBOV-C07) or a Central African isolate (EBOV-K). All animals infected with EBOV-C05 or EBOV-C07 died of EVD, whereas 2 of 3 EBOV-K-infected animals died. The viremia level was elevated 10-fold in EBOV-C05-infected animals, compared with EBOV-C07- or EBOV-K-infected animals. More-severe lung pathology was observed in 2 of 6 EBOV-C05/C07-infected macaques. This is the first detailed analysis of the recently circulating EBOV-C05/C07 in direct comparison to EBOV-K with 6 animals per group, and it showed that EBOV-C05 but not EBOV-C07 can replicate at higher levels and cause more tissue damage in some animals. Increased virus shedding from individuals who are especially susceptible to EBOV replication is possibly one of the many challenges facing the community of healthcare and policy-making responders since the beginning of the outbreak.

The magnitude of the 2014-2016 West African Ebola virus outbreak has highlighted the importance of immediate and rapid deployment of control measures in affected areas. While many prophylactic and therapeutic options entered clinical trials in the past two years, larger use to impact on Ebola spread will not be possible until at least one product meets final approval by regulatory agencies. Control of the West African outbreak was achieved almost entirely by breaking chain of transmissions through case identification and specialized treatment, communication, safe burials and other proven methods. To achieve this in a timely manner, epidemiologists and medical teams are working in concert with laboratories to identify infected individuals and provide care within Ebola treatment units. Herein, we review an outbreak response workflow from the point of view of mobile laboratories and summarize methods that have been used by them during the West African Ebola virus outbreak of 2014-2016.

The 2014-2015 Ebola virus (EBOV) outbreak in West Africa highlighted the urgent need for specific therapeutic interventions for infected patients. The human-mouse chimeric monoclonal antibody (mAb) cocktail ZMapp, previously shown to be efficacious in EBOV (variant Kikwit) lethally infected nonhuman primates (NHPs) when administration was initiated up to 5 days, was used in some patients during the outbreak. We show that a two-antibody cocktail, MIL77E, is fully protective in NHPs when administered at 50 mg/kg 3 days after challenge with a lethal dose of EBOV variant Makona, the virus responsible for the ongoing 2014-2015 outbreak, whereas a similar formulation of ZMapp protected two of three NHPs. The chimeric MIL77E mAb cocktail is produced in engineered Chinese hamster ovary cells and is based on mAbs c13C6 and c2G4 from ZMapp. The use of only two antibodies in MIL77E opens the door to a pan-ebolavirus cocktail.

A nanopore DNA sequencer is used for real-time genomic surveillance of the Ebola virus epidemic in the field in Guinea; the authors demonstrate that it is possible to pack a genomic surveillance laboratory in a suitcase and transport it to the field for on-site virus sequencing, generating results within 24 hours of sample collection. This paper reports the use of nanopore DNA sequencers (known as MinIONs) for real-time genomic surveillance of the Ebola virus epidemic, in the field in Guinea. The authors demonstrate that it is possible to pack a genomic surveillance laboratory in a suitcase and transport it to the field for on-site virus sequencing, generating results within 24 hours of sample collection. The Ebola virus disease epidemic in West Africa is the largest on record, responsible for over 28,599 cases and more than 11,299 deaths1. Genome sequencing in viral outbreaks is desirable to characterize the infectious agent and determine its evolutionary rate. Genome sequencing also allows the identification of signatures of host adaptation, identification and monitoring of diagnostic targets, and characterization of responses to vaccines and treatments. The Ebola virus (EBOV) genome substitution rate in the Makona strain has been estimated at between 0.87 × 10−3 and 1.42 × 10−3 mutations per site per year. This is equivalent to 16–27 mutations in each genome, meaning that sequences diverge rapidly enough to identify distinct sub-lineages during a prolonged epidemic2,3,4,5,6,7. Genome sequencing provides a high-resolution view of pathogen evolution and is increasingly sought after for outbreak surveillance. Sequence data may be used to guide control measures, but only if the results are generated quickly enough to inform interventions8. Genomic surveillance during the epidemic has been sporadic owing to a lack of local sequencing capacity coupled with practical difficulties transporting samples to remote sequencing facilities9. To address this problem, here we devise a genomic surveillance system that utilizes a novel nanopore DNA sequencing instrument. In April 2015 this system was transported in standard airline luggage to Guinea and used for real-time genomic surveillance of the ongoing epidemic. We present sequence data and analysis of 142 EBOV samples collected during the period March to October 2015. We were able to generate results less than 24 h after receiving an Ebola-positive sample, with the sequencing process taking as little as 15–60 min. We show that real-time genomic surveillance is possible in resource-limited settings and can be established rapidly to monitor outbreaks.

Currently, no approved antiviral therapeutic is available for treatment or prevention of Ebola virus (EBOV) infection. In this study, we characterized an EBOV-glycoprotein (GP) pseudotyped HIV-1-based vector system in different cell cultures, including human umbilical vein endothelial cells (HUVECs) and human macrophages, for the screening of anti-EBOV-GP agent(s). Based on this system, we demonstrated that an aqueous extract (CHPV) from the Chinese herb Prunella vulgaris displayed a potent inhibitory effect on EBOV-GP pseudotyped virus (EBOV-GP-V)-mediated infection in various cell lines, including HUVEC and macrophage. In addition, our results indicated that CHPV was able to block an eGFP-expressing Zaire ebola virus (eGFP-ZEBOV) infection in VeroE6 cells. The anti-EBOV activity of CHPV was exhibited in a dose-dependent manner. At a 12.5 μg/ml concentration, the CHPV showed a greater than 80% inhibition of EBOV-GP-V and eGFP-EBOV infections. Likewise, our studies suggested that the inhibitory effect of CHPV occurred by binding directly to EBOV-GP-Vs and blocking the early viral events. Interestingly, our results have shown that CHPV was able to enhance the anti-EBOV activity of the monoclonal antibody MAb 2G4 against EBOV-GP. Overall, this study provides evidence that CHPV has anti-EBOV activity and may be developed as a novel antiviral approach against EBOV infection., Highlights • We characterized the infection of an EBOV-GP pseudotyped HIV-based vector in human endothelial cells and macrophages. • We identified an aqueous extract of Prunella vulgaris which displayed a potent inhibition of EBOV-GP mediated viral entry. • The inhibitory effect of Chinese herb P. vulgaris (CHPV) is through a directly binding to EBOV-GP. • The presence of CHPV enhances antiviral activity of a monoclonal antibody MAb against EBOV-GP. • This study provides the evidence that CHPV has potential to be developed as a new anti- EBOV agent.

In nonhuman primates, complete protection against an Ebola virus (EBOV) challenge has previously beenachieved after a single injection with several vaccine platforms. However, long-term protection against EBOVafter a single immunization has not been demonstrated to this date. Interestingly, prime-boost regimens havedemonstrated longer protection against EBOV challenge, compared with single immunizations. Since prime-boost regimens have the potential to achieve long-term protection, determining optimal vectorcombinations iscrucial.However,testingprime-boostefficiencyinlong-termprotectionstudiesistimeconsumingandresourcedemanding. Here, we investigated the optimal prime-boost combination, using DNA, porcine-derived adeno-associated virus serotype 6 (AAV-po6), and human adenovirus serotype 5 (Ad5) vector, in a short-term protec-tion study in the mouse model of EBOV infection. In addition, we also investigated which immune parameterswere indicative of a strong boost. Each vaccine platform was titrated in mice to identify which dose (single im-munization) induced approximately 20% protection after challenge with a mouse-adapted EBOV. These doseswerethenusedtodeterminetheprotectionefficacyofvariousprime-boostcombinations,usingthesamemousemodel. In addition, humoral and cellular immune responses against EBOV glycoprotein were analyzed by anenzyme-linkedimmunosorbentassay,aneutralizingantibodyassay,andaninterferonγ–specificenzyme-linkedimmunospot assay. When DNA was used as a prime, Ad5 boost induced the best protection, which correlatedwith a higher cellular response. In contrast, when AAV-po6 or Ad5 were injected first, better protection wasachieved after DNA boost, and this correlated with a higher total glycoprotein-specific immunoglobulin Gtiter. Prime-boost regimens using independent vaccine platforms may provide a useful strategy to inducelong-term immune protection against filoviruses.Keywords. Ebola virus; prime-boost; vaccine; adenovirus; DNA; adeno-associated virus.Ebolavirus (EBOV) causes the most severe form ofhemorrhagicfeverknowntodate.Currentmanagementof EBOV-infected individuals mainly consists of sup-portive care, as no approved treatments or vaccinesagainst EBOV are commercially available [1, 2]. Thelack of approved therapeutics, high mortality rate, andease of transmission have prompted research on the de-velopment of both treatments and vaccines againstEBOV.Protection against EBOV challenge has been demon-strated in nonhuman primates (NHPs) after immuniza-tion with various vaccine platforms based on adenovirus(Ad) [3–5],vesicular stomatitis virus (VSV) [ 6],virus-likeparticles [7], human parainfluenza virus type 3 (HPIV3)[8],Newcastlediseasevirus[9],andreplication-competentrabies virus vector [10] encoding EBOV glycoprotein(GP). The efficacy of these platforms was mainly demon-strated28daysafterimmunization.However,lackoflong-term protection by these vaccine platforms would limittheir clinical use. Although protection against Marburgvirus challenge has been reported in NHPs approximately14 months after a single shot of VSV [ 11], to date, long-termprotectiveimmunityagainstEBOVhasonlybeenre-ported after a single dose of replication-competent rabiesvirus vector or after prime-boost regimens. After DNA/Ad5 or ChAd3/MVA prime-boost, NHPs were fully