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The development of new therapies against SARS-CoV-2 is required to extend the toolkit of intervention strategies to combat the global pandemic. In this study, hyperimmune plasma from sheep immunised with whole spike SARS-CoV-2 recombinant protein has been used to generate candidate products. In addition to purified IgG, we have refined candidate therapies by removing non-specific IgG via affinity binding along with fragmentation to eliminate the Fc region to create F(ab′)2 fragments. These preparations were evaluated for in vitro activity and demonstrated to be strongly neutralising against a range of SARS-CoV-2 strains, including Omicron B2.2. In addition, their protection against disease manifestations and viral loads were assessed using a hamster SARS-CoV-2 infection model. Results demonstrated protective effects of both IgG and F(ab′)2, with the latter requiring sequential dosing to maintain in vivo activity due to rapid clearance from the circulation. [ABSTRACT FROM AUTHOR]

Author(s): Paula Ruibal [1, 2, 3, 4]; Lisa Oestereich [2, 3, 4]; Anja Ldtke [1, 2, 3, 4]; Beate Becker-Ziaja [2, 3, 4]; David M. Wozniak [2, 3, 4]; Romy [...]

The ongoing emergence of SARS-CoV-2 virus variants remains a source of concern because it is accompanied by the potential for increased virulence as well as evasion of immunity. Here we show that, although having an almost identical spike gene sequence as another Omicron variant (BA.5.2.1), a BA.4 isolate lacked all the typical disease characteristics of other isolates seen in the Golden Syrian hamster model despite replicating almost as effectively. Animals infected with BA.4 had similar viral shedding profiles to those seen with BA.5.2.1 (up to day 6 post-infection), but they all failed to lose weight or present with any other significant clinical signs. We hypothesize that this lack of detectable signs of disease during infection with BA.4 was due to a small (nine nucleotide) deletion (∆686–694) in the viral genome (ORF1ab) responsible for the production of non-structural protein 1, which resulted in the loss of three amino acids (aa 141–143). [ABSTRACT FROM AUTHOR]

The golden Syrian hamster (Mesocricetus auratus) is now commonly used in preclinical research for the study of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the assessment of vaccines, drugs and therapeutics. Here, we show that hamsters inoculated via the intranasal route with the same infectious virus dose of prototypical SARS-CoV-2 administered in a different volume present with different clinical signs, weight loss and viral shedding, with a reduced volume resulting in reduced severity of disease similar to that obtained by a 500-fold reduction in the challenge dose. The tissue burden of the virus and the severity of pulmonary pathology were also significantly affected by different challenge inoculum volumes. These findings suggest that a direct comparison between the severity of SARS-CoV-2 variants or studies assessing the efficacy of treatments determined by hamster studies cannot be made unless both the challenge dose and inoculation volume are matched when using the intranasal route. Additionally, analysis of sub-genomic and total genomic RNA PCR data demonstrated no link between sub-genomic and live viral titres and that sub-genomic analyses do not provide any information beyond that provided by more sensitive total genomic PCR. [ABSTRACT FROM AUTHOR]

An imported case of monkeypox was diagnosed in December 2019 in a traveller returning from Nigeria to the UK. Subsequently, environmental sampling was performed at two adjoining single‐room residences occupied by the patient and their sibling. Monkeypox virus DNA was identified in multiple locations throughout both properties, and monkeypox virus was isolated from several samples 3 days after the patient was last in these locations. Positive samples were identified following the use of both vacuum and surface sampling techniques; these methodologies allowed for environmental analysis of potentially contaminated porous and non‐porous surfaces via real‐time quantitative reverse transcriptase PCR analysis in addition to viral isolation to confirm the presence of infection‐competent virus. This report confirms the potential for infection‐competent monkeypox virus to be recovered in environmental settings associated with known positive cases and the necessity for rapid environmental assessment to reduce potential exposure to close contacts and the general public. The methods adopted in this investigation may be used for future confirmed cases of monkeypox in order to establish levels of contamination, confirm the presence of infection‐competent material and to identify locations requiring additional cleaning. [ABSTRACT FROM AUTHOR]

The rapid global spread of severe acute respiratory coronavirus 2 (SARS-CoV-2) has resulted in an urgent effort to find efficacious therapeutics. Broad-spectrum therapies which could be used for other respiratory pathogens confer advantages, as do those based on targeting host cells that are not prone to the development of resistance by the pathogen. We tested an intranasally delivered carbohydrate-binding module (CBM) therapy, termed Neumifil, which is based on a CBM that has previously been shown to offer protection against the influenza virus through the binding of sialic acid receptors. Using the recognised hamster model of SARS-CoV-2 infection, we demonstrate that Neumifil significantly reduces clinical disease severity and pathological changes in the nasal cavity. Furthermore, we demonstrate Neumifil binding to the human angiotensin-converting enzyme 2 (ACE2) receptor and spike protein of SARS-CoV-2. This is the first report describing the testing of this type of broad-spectrum antiviral therapy in vivo and provides evidence for the advancement of Neumifil in further preclinical and clinical studies. [ABSTRACT FROM AUTHOR]

Background Ebola virus disease (EVD) is a highly lethal condition for which no specific treatment has proven efficacy. In September 2014, while the Ebola outbreak was at its peak, the World Health Organization released a short list of drugs suitable for EVD research. Favipiravir, an antiviral developed for the treatment of severe influenza, was one of these. In late 2014, the conditions for starting a randomized Ebola trial were not fulfilled for two reasons. One was the perception that, given the high number of patients presenting simultaneously and the very high mortality rate of the disease, it was ethically unacceptable to allocate patients from within the same family or village to receive or not receive an experimental drug, using a randomization process impossible to understand by very sick patients. The other was that, in the context of rumors and distrust of Ebola treatment centers, using a randomized design at the outset might lead even more patients to refuse to seek care. Therefore, we chose to conduct a multicenter non-randomized trial, in which all patients would receive favipiravir along with standardized care. The objectives of the trial were to test the feasibility and acceptability of an emergency trial in the context of a large Ebola outbreak, and to collect data on the safety and effectiveness of favipiravir in reducing mortality and viral load in patients with EVD. The trial was not aimed at directly informing future guidelines on Ebola treatment but at quickly gathering standardized preliminary data to optimize the design of future studies. Methods and Findings Inclusion criteria were positive Ebola virus reverse transcription PCR (RT-PCR) test, age [greater than or equal to] 1 y, weight [greater than or equal to] 10 kg, ability to take oral drugs, and informed consent. All participants received oral favipiravir (day 0: 6,000 mg; day 1 to day 9: 2,400 mg/d). Semi-quantitative Ebola virus RT-PCR (results expressed in 'cycle threshold' [Ct]) and biochemistry tests were performed at day 0, day 2, day 4, end of symptoms, day 14, and day 30. Frozen samples were shipped to a reference biosafety level 4 laboratory for RNA viral load measurement using a quantitative reference technique (genome copies/milliliter). Outcomes were mortality, viral load evolution, and adverse events. The analysis was stratified by age and Ct value. A 'target value' of mortality was defined a priori for each stratum, to guide the interpretation of interim and final analysis. Between 17 December 2014 and 8 April 2015, 126 patients were included, of whom 111 were analyzed (adults and adolescents, [greater than or equal to]13 y, n = 99; young children, [less than or equal to]6 y, n = 12). Here we present the results obtained in the 99 adults and adolescents. Of these, 55 had a baseline Ct value [greater than or equal to] 20 (Group A Ct [greater than or equal to] 20), and 44 had a baseline Ct value < 20 (Group A Ct < 20). Ct values and RNA viral loads were well correlated, with Ct = 20 corresponding to RNA viral load = 7.7 log.sub.10 genome copies/ml. Mortality was 20% (95% CI 11.6%-32.4%) in Group A Ct [greater than or equal to] 20 and 91% (95% CI 78.8%-91.1%) in Group A Ct < 20. Both mortality 95% CIs included the predefined target value (30% and 85%, respectively). Baseline serum creatinine was [greater than or equal to]110 [mu]mol/l in 48% of patients in Group A Ct [greater than or equal to] 20 ([greater than or equal to]300 [mu]mol/l in 14%) and in 90% of patients in Group A Ct < 20 ([greater than or equal to]300 [mu]mol/l in 44%). In Group A Ct [greater than or equal to] 20, 17% of patients with baseline creatinine [greater than or equal to]110 [mu]mol/l died, versus 97% in Group A Ct < 20. In patients who survived, the mean decrease in viral load was 0.33 log.sub.10 copies/ml per day of follow-up. RNA viral load values and mortality were not significantly different between adults starting favipiravir within Conclusions In the context of an outbreak at its peak, with crowded care centers, randomizing patients to receive either standard care or standard care plus an experimental drug was not felt to be appropriate. We did a non-randomized trial. This trial reaches nuanced conclusions. On the one hand, we do not conclude on the efficacy of the drug, and our conclusions on tolerance, although encouraging, are not as firm as they could have been if we had used randomization. On the other hand, we learned about how to quickly set up and run an Ebola trial, in close relationship with the community and non-governmental organizations; we integrated research into care so that it improved care; and we generated knowledge on EVD that is useful to further research. Our data illustrate the frequency of renal dysfunction and the powerful prognostic value of low Ct values. They suggest that drug trials in EVD should systematically stratify analyses by baseline Ct value, as a surrogate of viral load. They also suggest that favipiravir monotherapy merits further study in patients with medium to high viremia, but not in those with very high viremia. Trial registration ClinicalTrials.gov NCT02329054, Author(s): Daouda Sissoko 1,2, Cedric Laouenan 3,4, Elin Folkesson 5, Abdoul-Bing M'Lebing 6, Abdoul-Habib Beavogui 7, Sylvain Baize 8,9, Alseny-Modet Camara 5, Piet Maes 10,11, Susan Shepherd 6, Christine Danel [...]

Hospital tap water is a recognised source ofPseudomonas aeruginosa. UK guidance documents recommend measures to control/minimise the risk ofP. aeruginosain augmented care units but these are based on limited scientific evidence. An experimental water distribution system was designed to investigate colonisation of hospital tap components.P. aeruginosawas injected into 27 individual tap ‘assemblies’. Taps were subsequently flushed twice daily and contamination levels monitored over two years. Tap assemblies were systematically dismantled and assessed microbiologically and the effect of removing potentially contaminated components was determined.P. aeruginosawas repeatedly recovered from the tap water at levels above the augmented care alert level. The organism was recovered from all dismantled solenoid valves with colonisation of the ethylene propylene diene monomer (EPDM) diaphragm confirmed by microscopy. Removing the solenoid valves reducedP. aeruginosacounts in the water to below detectable levels. This effect was immediate and sustained, implicating the solenoid diaphragm as the primary contamination source. [ABSTRACT FROM AUTHOR]

Antibodies against SARS-CoV-2 are important to generate protective immunity, with convalescent plasma one of the first therapies approved. An alternative source of polyclonal antibodies suitable for upscaling would be more amendable to regulatory approval and widespread use. In this study, sheep were immunised with SARS-CoV-2 whole spike protein or one of the subunit proteins: S1 and S2. Once substantial antibody titres were generated, plasma was collected and samples pooled for each antigen. Non-specific antibodies were removed via affinity-purification to yield candidate products for testing in a hamster model of SARS-CoV-2 infection. Affinity-purified polyclonal antibodies to whole spike, S1 and S2 proteins were evaluated for in vitro for neutralising activity against SARS-CoV-2 Wuhan-like virus (Australia/VIC01/2020) and a recent variant of concern, B.1.1.529 BA.1 (Omicron), antibody-binding, complement fixation and phagocytosis assays were also performed. All antibody preparations demonstrated an effect against SARS-CoV-2 disease in the hamster model of challenge, with those raised against the S2 subunit providing the most promise. A rapid, cost-effective therapy for COVID-19 was developed which provides a source of highly active immunoglobulin specific to SARS-CoV-2 with multi-functional activity. [ABSTRACT FROM AUTHOR]

The mutation profile of the SARS-CoV-2 Omicron (lineage BA.1) variant posed a concern for naturally acquired and vaccine-induced immunity. We investigated the ability of prior infection with an early SARS-CoV-2 ancestral isolate (Australia/VIC01/2020, VIC01) to protect against disease caused by BA.1. We established that BA.1 infection in naïve Syrian hamsters resulted in a less severe disease than a comparable dose of the ancestral virus, with fewer clinical signs including less weight loss. We present data to show that these clinical observations were almost absent in convalescent hamsters challenged with the same dose of BA.1 50 days after an initial infection with ancestral virus. These data provide evidence that convalescent immunity against ancestral SARS-CoV-2 is protective against BA.1 in the Syrian hamster model of infection. Comparison with published pre-clinical and clinical data supports consistency of the model and its predictive value for the outcome in humans. Further, the ability to detect protection against the less severe disease caused by BA.1 demonstrates continued value of the Syrian hamster model for evaluation of BA.1-specific countermeasures., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Ryan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Modern microbiology laboratories are designed to protect workers and the environment from microbial aerosols produced during microbiological procedures and accidents. However, there is only limited data available on the aerosols generated from common microbiology procedures., Methods: A series of common microbiological procedures were undertaken with high concentration spore suspensions while air samplers were operated to sample the aerosols generated. Surface contamination from droplets was visualized using sodium fluorescein within the suspension. A total of 36 procedures were studied using different sample volumes (0.1-10 mL) and two spore suspension titers (10 7 and 10 9 colony forming units [cfu]/mL)., Results: The aerosol concentrations generated varied from 0 to 13,000 cfu/m 3 . There was evidence to suggest that titer, volume, and poor use of equipment were significant factors in increased aerosol generation from some of the procedures. A risk assessment undertaken using the data showed that any aerosol generated from these processes would be contained within a correctly operating biological safety cabinet. Therefore, with these procedures, the operator and the environment would not require any additional protective measures such as respiratory protective equipment or a negative pressure laboratory to prevent aerosol exposure or release., Conclusions: Aerosol generation from common laboratory processes can be minimized by reducing sample volumes and concentrations if possible. Training laboratory staff in good microbiological techniques would further mitigate aerosols generated from common laboratory processes., Competing Interests: No competing financial interests exist., (© Thomas Pottage et al. 2022; Published by Mary Ann Liebert, Inc.)

Background: The novel human coronavirus SARS-CoV-2 is a major ongoing global threat with huge economic burden. Like all respiratory viruses, SARS-CoV-2 initiates infection in the upper respiratory tract (URT). Infected individuals are often asymptomatic, yet highly infectious and readily transmit virus. A therapy that restricts initial replication in the URT has the potential to prevent progression of severe lower respiratory tract disease as well as limiting person-to-person transmission., Methods: SARS-CoV-2 Victoria/01/2020 was passaged in Vero/hSLAM cells and virus titre determined by plaque assay. Challenge virus was delivered by intranasal instillation to female ferrets at 5.0 × 10 6  pfu/ml. Treatment groups received intranasal INNA-051, developed by Ena Respiratory. SARS-CoV-2 RNA was detected using the 2019-nCoV CDC RUO Kit and QuantStudio™ 7 Flex Real-Time PCR System. Histopathological analysis was performed using cut tissues stained with haematoxylin and eosin (H&E)., Findings: We show that prophylactic intra-nasal administration of the TLR2/6 agonist INNA-051 in a SARS-CoV-2 ferret infection model effectively reduces levels of viral RNA in the nose and throat. After 5 days post-exposure to SARS-CoV-2, INNA-051 significantly reduced virus in throat swabs (p=<0.0001) by up to a 24 fold (96% reduction) and in nasal wash (p=0.0107) up to a 15 fold (93% reduction) in comparison to untreated animals., Interpretation: The results of our study support clinical development of a therapy based on prophylactic TLR2/6 innate immune activation in the URT, to reduce SARS-CoV-2 transmission and provide protection against COVID-19., Funding: This work was funded by Ena Respiratory, Melbourne, Australia., Competing Interests: Declaration of Competing Interests Authors report grants from Ena Respiratory, during the conduct of the study. W. Zeng and D.C. Jackson reports grants from Ena Therapeutics, during the conduct of the study. D. Tsitoura, C. Demaison, F. Mercuri, I. Holmes and N.W. Bartlett reports personal fees and other from Ena Therapeutics, outside the submitted work. D.C. Jackson, W. Zeng and B.Y. Chua reports other from Ena Therapeutics, outside the submitted work. Dr. Holmes reports personal fees from Ena Therapeutics, outside the submitted work. In addition, D. Tsitoura, C. Demaison and F. Mercuri have a patent AU 2020901709 pending to Ena Therapeutics. D.C Jackson, W. Zeng and C. Demaison have a patent PCT/AU2011/001225 issued to Ena Therapeutics. D.C Jackson, W. Zeng, I. Holmes and C. Demaison have a patent PCT/AU2020/050660 pending to Ena Therapeutics., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)