10 June, 2021

An outbreak of SARS-CoV-2 with high mortality in mink (Neovison vison) on multiple Utah farms -

The breadth of animal hosts that are susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and may serve as reservoirs for continued viral transmission are not known entirely. In August 2020, an outbreak of SARS-CoV-2 occurred in multiple mink farms in Utah and was associated with high mink mortality and rapid viral transmission between animals. The outbreak’s epidemiology, pathology, molecular characterization, and tissue distribution of virus within infected mink is provided. Infection of mink was likely by reverse zoonosis. Once established, infection spread rapidly between independently housed animals and farms, and caused severe respiratory disease and death. Clinical signs were most notably sudden death, anorexia, and increased respiratory effort. Gross pathology examination revealed severe pulmonary congestion and edema. Microscopically there was pulmonary edema with moderate vasculitis, perivasculitis, and fibrinous interstitial pneumonia. Reverse transcriptase polymerase chain reaction (RT-PCR) of tissues collected at necropsy demonstrated the presence of SARS-CoV-2 viral RNA in multiple organs including nasal turbinates, lung, tracheobronchial lymph node, epithelial surfaces, and others. Whole genome sequencing from multiple mink was consistent with published SARS-CoV-2 genomes with few polymorphisms. The Utah mink SARS-CoV-2 strain fell into Clade GH, which is unique among mink and other animal strains sequenced to date and did not share other spike RBD mutations Y453F and F486L found in mink. Localization of viral RNA by in situ hybridization revealed a more localized infection, particularly of the upper respiratory tract. Mink in the outbreak reported herein had high levels of virus in the upper respiratory tract associated with mink-to-mink transmission in a confined housing environment and were particularly susceptible to disease and death due to SARS-CoV-2 infection.

🖺 Full Text HTML: An outbreak of SARS-CoV-2 with high mortality in mink (Neovison vison) on multiple Utah farms

Estimating the direct Covid-19 disability-adjusted life years impact on the Malta population for the first full year -

Background Disability-adjusted life years (DALYs) combine the impact of morbidity and mortality, allowing for comprehensive comparisons of the population health impact of diseases, injuries, and risk factors. The aim of this paper was to estimate the DALYs due to Covid-19 in Malta (March 2020-21) and investigate its impact in relation to other causes of disease and injury, at a population level. Methods Mortality and weekly hospital admission reported data were used to calculate the DALYs, based on the European Burden of Disease Network consensus Covid-19 model. Covid-19 infection durations of 14 days was considered. Sensitivity analyses for different morbidity scenarios, including post-acute consequences were presented. Estimates were for March 2020-21. Results An estimated 70,421 people were infected (with and without symptoms) by Covid-19 in Malta (March 2020-21), out of which 1,636 required hospitalisation and 331 deaths, contributing to 5,478 DALYs. These DALYs positioned Covid-19 as the fourth leading cause of disease and injury in Malta. Mortality contributed to 95% of DALYs, while post-acute consequences contributed to 60% of morbidity. Conclusion Covid-19 over a period of one year has impacted substantially the population health in Malta. Post-acute consequences are the leading morbidity factors that require urgent targeted action to ensure timely multidisciplinary care. It is recommended that DALY estimations in 2021 and beyond are calculated to assess the impact of vaccine roll-out and emergence of new variants on population health.

🖺 Full Text HTML: Estimating the direct Covid-19 disability-adjusted life years impact on the Malta population for the first full year

Overcoming Supply Chain Disruptions During Pandemics by Utilizing Found Hardware for Open Source Gentle Ventilation -

The COVID-19 pandemic created temporary shortages of medical equipment like ventilators throughout the world. Recent medical research also indicates a gentle ventilation may be more appropriate for many patients. This article details the design of an open source gentle ventilator (gentle-vent) framework that can be used in periods of scarcity when no other options are available. The system utilizes a wide range of commonly available components that are combined using basic electronics skills to achieve the desired end product. The firmware is programed in the Arduino IDE using any Arduino compatible microcontroller. The main function of the gentle-vent is to generate a calibrated pressure wave at the pump to provide support to the patient’s breathing. Each gentle-vent permutation was tested using a DIY manometer as it could be done in the field in low-resource settings. These measurements were also verified with an open source VentMon. All permutations were able to accurately hold a desired setpoint for at least 2 hours. The most rudimentary implementation using found mechanical components and perf-board costs less than $20. The results indicate that an open source approach can be used to make breathing support accessible in most contexts.

🖺 Full Text HTML: Overcoming Supply Chain Disruptions During Pandemics by Utilizing Found Hardware for Open Source Gentle Ventilation

The Impact of Personality and Situational Factors on Perceived Stress: An Investigation During COVID-19 Pandemic -

The study investigates the relationship between personality and situational factors on perceived stress level during the global COVID-19 pandemic. Analysis of data collected from people across different territories confirms the association between personality traits and perceived stress level. Furthermore, the paper shows that people are experiencing moderate stress, which is affected by where they are residing, whether their personal finance is at risk, and their usage of social media during the pandemic.

🖺 Full Text HTML: The Impact of Personality and Situational Factors on Perceived Stress: An Investigation During COVID-19 Pandemic

Country-wide genomic surveillance of SARS-CoV-2 strains -

Genomic surveillance has enabled the identification of several SARS-CoV-2 variants, allowing the formulation of appropriate public health policies. However, surveillance could be made more effective. We have determined that the time taken from strain collection to genome submission for over 1.7 million SARS-CoV-2 strains available at GISAID. We find that strain-wise, time lag in this process ranges from one day to over a year. Country-wise, the UK has taken a median of 16 days (for 417,287 genomes), India took 57 days (for 15,614 genomes), whereas Qatar spent 289 days (for 2298 genomes). We strongly emphasize that along with increasing the number of genomes of COVID-19 positive cases sequenced, their accelerated submission to GISAID should also be strongly encouraged and facilitated. This will enable researchers across the globe to track the spreading of variants in a timely manner; analyse their biology, epidemiology, and re-emerging infections; and define effective public health policies.

🖺 Full Text HTML: Country-wide genomic surveillance of SARS-CoV-2 strains

Neutralizing antibodies elicited by the Ad26.COV2.S COVID-19 vaccine show reduced activity against 501Y.V2 (B.1.351), despite protection against severe disease by this variant. -

The emergence of SARS-CoV-2 variants, such as 501Y.V2, with immune evasion mutations in the spike has resulted in reduced efficacy of several COVID-19 vaccines. However, the efficacy of the Ad26.COV2.S vaccine, when tested in South Africa after the emergence of 501Y.V2, was not adversely impacted. We therefore assessed the binding and neutralization capacity of n=120 South African sera (from Day 29, post-vaccination) from the Janssen phase 3 study, Ensemble. Spike binding assays using both the Wuhan-1 D614G and 501Y.V2 Spikes showed high levels of cross-reactivity. In contrast, in a subset of 27 sera, we observed significantly reduced neutralization of 501Y.V2 compared to Wuhan-1 D614G, with 22/27 (82%) of sera showing no detectable neutralization of 501Y.V2 at Day 29. These data suggest that even low levels of neutralizing antibodies may contribute to protection from moderate/severe disease. In addition, Fc effector function and T cells may play an important role in protection by this vaccine against 501Y.V2.

🖺 Full Text HTML: Neutralizing antibodies elicited by the Ad26.COV2.S COVID-19 vaccine show reduced activity against 501Y.V2 (B.1.351), despite protection against severe disease by this variant.

Oral subunit SARS-CoV-2 vaccine induces systemic neutralizing IgG, IgA and cellular immune responses and can boost neutralizing antibody responses primed by an injected vaccine -

The rapid spread of the COVID-19 pandemic, with its devastating medical and economic impacts, triggered an unprecedented race toward development of effective vaccines. The commercialized vaccines are parenterally administered, which poses logistic challenges, while adequate protection at the mucosal sites of virus entry is questionable. Furthermore, essentially all vaccine candidates target the viral spike (S) protein, a surface protein that undergoes significant antigenic drift. This work aimed to develop an oral multi-antigen SARS-CoV-2 vaccine comprised of the receptor binding domain (RBD) of the viral S protein, two domains of the viral nucleocapsid protein (N), and heat-labile enterotoxin B (LTB), a potent mucosal adjuvant. The humoral, mucosal and cell-mediated immune responses of both a three-dose vaccination schedule and a heterologous subcutaneous prime and oral booster regimen were assessed in mice and rats, respectively. Mice receiving the oral vaccine compared to control mice showed significantly enhanced post-dose-3 virus-neutralizing antibody, anti-S IgG and IgA production and N-protein-stimulated IFN-{gamma}and IL-2 secretion by T cells. When administered as a booster to rats following parenteral priming with the viral S1 protein, the oral vaccine elicited markedly higher neutralizing antibody titres than did oral placebo booster. A single oral booster following two subcutaneous priming doses elicited serum IgG and mucosal IgA levels similar to those raised by three subcutaneous doses. In conclusion, the oral LTB-adjuvanted multi-epitope SARS-CoV-2 vaccine triggered versatile humoral, cellular and mucosal immune responses, which are likely to provide protection, while also minimizing technical hurdles presently limiting global vaccination, whether by priming or booster programs.

🖺 Full Text HTML: Oral subunit SARS-CoV-2 vaccine induces systemic neutralizing IgG, IgA and cellular immune responses and can boost neutralizing antibody responses primed by an injected vaccine

DNA damage response at telomeres boosts the transcription of SARS-CoV-2 receptor ACE2 during aging -

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is known to be more common in the elderly, who show also more severe symptoms and a higher risk of hospitalization and death. Here we show that the expression of the Angiotensin Converting Enzyme 2 (ACE2), the SARS-CoV2 cell receptor, increases during aging in mouse and human lungs, and following telomere shortening or dysfunction in mammalian cells and in mouse models. This increase is regulated at the transcription level, and Ace2 promoter activity is DNA damage response (DDR)-dependent. Indeed, ATM inhibition or the selective inhibition of telomeric DDR, through the use of antisense oligonucleotides, prevents Ace2 upregulation following telomere damage, in cultured cells and in mice. We propose that during aging telomeric shortening, by triggering DDR activation, causes the upregulation of ACE2, the SARS-CoV2 cell receptor, thus making the elderly likely more susceptible to the infection.

🖺 Full Text HTML: DNA damage response at telomeres boosts the transcription of SARS-CoV-2 receptor ACE2 during aging

Monitoring group activity of hamsters and mice as a novel tool to evaluate COVID-19 progression, convalescence and rVSV-ΔG-spike vaccination efficacy -

COVID-19 pandemic initiated a worldwide race toward the development of treatments and vaccines. Small animal models were the Syrian golden hamster and the K18-hACE2 mice infected with SARS-CoV-2 to display a disease state with some aspects of the human COVID-19. Group activity of animals in their home cage continuously monitored by the HCMS100 was used as a sensitive marker of disease, successfully detecting morbidity symptoms of SARS-CoV-2 infection in hamsters and in K18-hACE2 mice. COVID-19 convalescent hamsters re-challenged with SARS-CoV-2, exhibited minor reduction in group activity compared to naive hamsters. To evaluate rVSV-{Delta}G-spike vaccination efficacy against SARS-CoV-2, we used the HCMS100 to monitor group activity of hamsters in their home cage. Single-dose rVSV-{Delta}G-spike vaccination of immunized group showed a faster recovery compared to the non-immunized infected hamsters, substantiating the efficacy of rVSV-{Delta}G-spike vaccine. HCMS100 offers non-intrusive, hands-free monitoring of a number of home cages of hamsters or mice modeling COVID-19.

🖺 Full Text HTML: Monitoring group activity of hamsters and mice as a novel tool to evaluate COVID-19 progression, convalescence and rVSV-ΔG-spike vaccination efficacy

Multi-color super-resolution imaging to study human coronavirus RNA during cellular infection -

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the third human coronavirus within 20 years that gave rise to a life-threatening disease and the first to reach pandemic spread. To make therapeutic headway against current and future coronaviruses, the biology of coronavirus RNA during infection must be precisely understood. Here, we present a robust and generalizable framework combining high-throughput confocal and super-resolution microscopy imaging to study coronavirus infection at the nanoscale. Employing the model human coronavirus HCoV-229E, we specifically labeled coronavirus genomic RNA (gRNA) and double-stranded RNA (dsRNA) via multicolor RNA-immunoFISH and visualized their localization patterns within the cell. The exquisite resolution of our approach uncovers a striking spatial organization of gRNA and dsRNA into three distinct structures and enables quantitative characterization of the status of the infection after antiviral drug treatment. Our approach provides a comprehensive framework that supports investigations of coronavirus fundamental biology and therapeutic effects.

🖺 Full Text HTML: Multi-color super-resolution imaging to study human coronavirus RNA during cellular infection

The fatty acid site is coupled to functional motifs in the SARS-CoV-2 spike protein and modulates spike allosteric behaviour -

The SARS-CoV-2 spike protein is the first contact point between the SARS-CoV-2 virus and host cells and mediates membrane fusion. Recently, a fatty acid binding site was identified in the spike (Toelzer et al. Science 2020). The presence of linoleic acid at this site modulates binding of the spike to the human ACE2 receptor, stabilizing a locked conformation of the protein. Here, dynamical-nonequilibrium molecular dynamics simulations reveal that this fatty acid site is coupled to functionally relevant regions of the spike, some of them far from the fatty acid binding pocket. Removal of a ligand from the fatty acid binding site significantly affects the dynamics of distant, functionally important regions of the spike, including the receptor-binding motif, furin cleavage site and fusion-peptide-adjacent regions. The results also show significant differences in behaviour between clinical variants of the spike: e.g. the D614G mutation shows a significantly different conformational response for some structural motifs relevant for binding and fusion. The simulations identify structural networks through which changes at the fatty acid binding site are transmitted within the protein. These communication networks significantly involve positions that are prone to mutation, indicating that observed genetic variation in the spike may alter its response to linoleate binding and associated allosteric communication.

🖺 Full Text HTML: The fatty acid site is coupled to functional motifs in the SARS-CoV-2 spike protein and modulates spike allosteric behaviour

Cellular Activities of SARS-CoV-2 Main Protease Inhibitors Reveal Their Unique Characteristics -

As an essential enzyme of SARS-CoV-2, the pathogen of COVID-19, main protease (MPro) triggers acute toxicity to its human cell host, an effect that can be alleviated by an MPro inhibitor with cellular potency. By coupling this toxicity alleviation with the expression of an MPro-eGFP fusion protein in a human cell host for straightforward characterization with fluorescent flow cytometry, we developed an effective method that allows bulk analysis of cellular potency of MPro inhibitors. In comparison to an antiviral assay in which MPro inhibitors may target host proteases or other processes in the SARS-CoV-2 life cycle to convene strong antiviral effects, this novel assay is more advantageous in providing precise cellular MPro inhibition information for assessment and optimization of MPro inhibitors. We used this assay to analyze 30 literature reported MPro inhibitors including MPI1-9 that were newly developed aldehyde-based reversible covalent inhibitors of MPro, GC376 and 11a that are two investigational drugs undergoing clinical trials for the treatment of COVID-19 patients in United States, boceprevir, calpain inhibitor II, calpain inhibitor XII, ebselen, bepridil that is an antianginal drug with potent anti-SARS-CoV-2 activity, and chloroquine and hydroxychloroquine that were previously shown to inhibit MPro. Our results showed that most inhibitors displayed cellular potency much weaker than their potency in direct inhibition of the enzyme. Many inhibitors exhibited weak or undetectable cellular potency up to 10 M. On contrary to their strong antiviral effects, 11a, calpain inhibitor II, calpain XII, ebselen, and bepridil showed relatively weak to undetectable cellular MPro inhibition potency implicating their roles in interfering with key steps other than just the MPro catalysis in the SARS-CoV-2 life cycle to convene potent antiviral effects. characterization of these molecules on their antiviral mechanisms will likely reveal novel drug targets for COVID-19. Chloroquine and hydroxychloroquine showed close to undetectable cellular potency to inhibit MPro. Kinetic recharacterization of these two compounds rules out their possibility as MPro inhibitors. Our results also revealed that MPI5, 6, 7, and 8 have high cellular and antiviral potency with both IC50 and EC50 values respectively below 1 M. As the one with the highest cellular and antiviral potency among all tested compounds, MPI8 has a remarkable cellular MPro inhibition IC50 value of 31 nM that matches closely to its strong antiviral effect with an EC50 value of 30 nM. Given its strong cellular and antiviral potency, we cautiously suggest that MPI8 is ready for preclinical and clinical investigations for the treatment of COVID-19.

🖺 Full Text HTML: Cellular Activities of SARS-CoV-2 Main Protease Inhibitors Reveal Their Unique Characteristics

A Pharmacophore Model for SARS-CoV-2 3CLpro Small Molecule Inhibitors and in Vitro Experimental Validation of Computationally Screened Inhibitors -

Among the biomedical efforts in response to the current coronavirus (COVID-19) pandemic, pharmacological strategies to reduce viral load in patients with severe forms of the disease are being studied intensively. One of the main drug target proteins proposed so far is the SARS-CoV-2 viral protease 3CLpro (also called Mpro), an essential component for viral replication. Ongoing ligand- and receptor-based computational screening efforts would be facilitated by an improved understanding of the electrostatic, hydrophobic and steric features that characterize small molecule inhibitors binding stably to 3CLpro, as well as by an extended collection of known binders. Here, we present combined virtual screening, molecular dynamics simulation, machine learning and in vitro experimental validation analyses which have led to the identification of small molecule inhibitors of 3CLpro with micromolar activity, and to a pharmacophore model that describes functional chemical groups associated with the molecular recognition of ligands by the 3CLpro binding pocket. Experimentally validated inhibitors using a ligand activity assay include natural compounds with available prior knowledge on safety and bioavailability properties, such as the natural compound rottlerin (IC50 = 37 mcM), and synthetic compounds previously not characterized (e.g. compound CID 46897844, IC50 = 31 mcM). In combination with the developed pharmacophore model, these and other confirmed 3CLpro inhibitors may provide a basis for further similarity-based screening in independent compound databases and structural design optimization efforts, to identify 3CLpro ligands with improved potency and selectivity. Overall, this study suggests that the integration of virtual screening, molecular dynamics simulations and machine learning can facilitate 3CLpro-targeted small molecule screening investigations. Different receptor-, ligand- and machine learning-based screening strategies provided complementary information, helping to increase the number and diversity of identified active compounds. Finally, the resulting pharmacophore model and experimentally validated small molecule inhibitors for 3CLpro provide resources to support follow-up computational screening efforts for this drug target.

🖺 Full Text HTML: A Pharmacophore Model for SARS-CoV-2 3CLpro Small Molecule Inhibitors and in Vitro Experimental Validation of Computationally Screened Inhibitors

Emergency department admissions during COVID-19: explainable machine learning to characterise data drift and detect emergent health risks -

Supervised machine learning algorithms deployed in acute healthcare settings use data describing historical episodes to predict clinical outcomes. Clinical settings are dynamic environments and the underlying data distributions characterising episodes can change with time (a phenomenon known as data drift), and so can the relationship between episode characteristics and associated clinical outcomes (so-called, concept drift). We demonstrate how explainable machine learning can be used to monitor data drift in a predictive model deployed within a hospital emergency department. We use the COVID-19 pandemic as an exemplar cause of data drift, which has brought a severe change in operational circumstances. We present a machine learning classifier trained using (pre-COVID-19) data, to identify patients at high risk of admission to hospital during an emergency department attendance. We evaluate our model9s performance on attendances occurring pre-pandemic (AUROC 0.856 95%CI [0.852, 0.859]) and during the COVID-19 pandemic (AUROC 0.826 95%CI [0.814, 0.837]). We demonstrate two benefits of explainable machine learning (SHAP) for models deployed in healthcare settings: (1) By tracking the variation in a feature9s SHAP value relative to its global importance, a complimentary measure of data drift is found which highlights the need to retrain a predictive model. (2) By observing the relative changes in feature importance emergent health risks can be identified.

🖺 Full Text HTML: Emergency department admissions during COVID-19: explainable machine learning to characterise data drift and detect emergent health risks

Impact of vaccination on new SARS-CoV-2 infections in the United Kingdom -

The effectiveness of COVID-19 vaccination in preventing new SARS-CoV-2 infections in the general community is still unclear. Here, we used the Office for National Statistics (ONS) COVID-19 Infection Survey, a large community-based survey of individuals living in randomly selected private households across the UK, to assess the effectiveness of BNT162b2 (Pfizer-BioNTech) and ChAdOx1 nCoV-19 (Oxford-AstraZeneca; ChAdOx1) vaccines against any new SARS-CoV-2 PCR-positive tests, split according to self-reported symptoms, cycle threshold value (<30 versus ≥30) as a surrogate for viral load, and gene positivity pattern (compatible with B.1.1.7 or not). Using 1,945,071 RT-PCR results from nose and throat swabs taken from 383,812 participants between 1 December 2020 and 8 May 2021, we found that vaccination with the ChAdOx1 or BNT162b2 vaccines already reduced SARS-CoV-2 infections ≥21 days after the first dose (61%, 95% CI 54 to 68% versus 66%, 95% CI 60 to 71%, respectively) with greater reductions observed after a second dose (79%, 95% CI 65 to 88% versus 80%, 95% CI 73 to 85%, respectively). Largest reductions were observed for symptomatic infections and/or infections with a higher viral burden. Overall, COVID-19 vaccination reduced the number of new SARS-CoV-2 infections, with the largest benefit received after two vaccinations and against symptomatic and high viral burden infections, and with no evidence of difference between the BNT162b2 and ChAdOx1 vaccines.

🖺 Full Text HTML: Impact of vaccination on new SARS-CoV-2 infections in the United Kingdom

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