Safety and efficacy of inhaled nebulised interferon beta-1a (SNG001) for treatment of SARS-CoV-2 infection: a randomised, double-blind, placebo-controlled, phase 2 trial

Type-I interferon signatures in SARS-CoV-2 infected Huh7 cells

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes Coronavirus disease 2019 (COVID-19) has caused a global health emergency. A key feature of COVID-19 is dysregulated interferon-response. Type-I interferon (IFN-I) is one of the earliest antiviral innate immune responses following viral infection and plays a significant role in the pathogenesis of SARS-CoV-2. In this study, using a proteomics-based approach, we identified that SARS-CoV-2 infection induces delayed and dysregulated IFN-I signaling in Huh7 cells. We demonstrate that SARS-CoV-2 is able to inhibit RIG-I mediated IFN-β production. Our results also confirm the recent findings that IFN-I pretreatment is able to reduce the susceptibility of Huh7 cells to SARS-CoV-2, but not post-treatment. Moreover, senescent Huh7 cells, in spite of showing accentuated IFN-I response were more susceptible to SARS-CoV-2 infection, and the virus effectively inhibited IFIT1 in these cells. Finally, proteomic comparison between SARS-CoV-2, SARS-CoV, and MERS-CoV revealed a distinct differential regulatory signature of interferon-related proteins emphasizing that therapeutic strategies based on observations in SARS-CoV and MERS-CoV should be used with caution. Our findings provide a better understanding of SARS-CoV-2 regulation of cellular interferon response and a perspective on its use as a treatment. Investigation of different interferon-stimulated genes and their role in the inhibition of SARS-CoV-2 pathogenesis may direct novel antiviral strategies.

A diamidobenzimidazole STING agonist protects against SARS-CoV-2 infection

Coronaviruses are a family of RNA viruses that cause acute and chronic diseases of the upper and lower respiratory tract in humans and other animals. SARS-CoV-2 is a recently emerged coronavirus that has led to a global pandemic causing a severe respiratory disease known as COVID-19 with significant morbidity and mortality worldwide. The development of antiviral therapeutics are urgently needed while vaccine programs roll out worldwide. Here we describe a diamidobenzimidazole compound, diABZI-4, that activates STING and is highly effective in limiting SARS-CoV-2 replication in cells and animals. diABZI-4 inhibited SARS-CoV-2 replication in lung epithelial cells. Administration of diABZI-4 intranasally before or even after virus infection conferred complete protection from severe respiratory disease in K18-ACE2-transgenic mice infected with SARS-CoV-2. Intranasal delivery of diABZI-4 induced a rapid short-lived activation of STING, leading to transient proinflammatory cytokine production and lymphocyte activation in the lung associated with inhibition of viral replication. Our study supports the use of diABZI-4 as a host-directed therapy which mobilizes antiviral defenses for the treatment and prevention of COVID-19.

Innate immune and inflammatory responses to SARS-CoV-2: Implications for COVID-19

COVID-19 can result in severe disease characterized by significant immunopathology that is spurred by an exuberant, yet dysregulated, innate immune response with a poor adaptive response. A limited and delayed interferon I (IFN-I) and IFN-III response results in exacerbated proinflammatory cytokine production and in extensive cellular infiltrates in the respiratory tract, resulting in lung pathology. The development of effective therapeutics for patients with severe COVID-19 depends on our understanding of the pathological elements of this unbalanced innate immune response. Here, we review the mechanisms by which SARS-CoV-2 both activates and antagonizes the IFN and inflammatory response following infection, how a dysregulated cytokine and cellular response contributes to immune-mediated pathology in COVID-19, and therapeutic strategies that target elements of the innate response.

Circulating Type I Interferon Levels and COVID-19 Severity: A Systematic Review and Meta-Analysis

Introduction

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, resulting in a range of clinical manifestations and outcomes. Laboratory and immunological alterations have been considered as potential markers of disease severity and clinical evolution. Type I interferons (IFN-I), mainly represented by IFN-α and β, are a group of cytokines with an important function in antiviral responses and have played a complex role in COVID-19. Some studies have demonstrated that IFN-I levels and interferon response is elevated in mild cases, while other studies have noted this in severe cases. The involvement of IFN-I on the pathogenesis and outcomes of SARS-CoV-2 infection remains unclear. In this study, we summarize the available evidence of the association of plasma protein levels of type I IFN with the severity of COVID-19.

Methods

The PRISMA checklist guided the reporting of the data. A systematic search of the MEDLINE (PubMed), EMBASE, and Web of Science databases was performed up to March of 2021, looking for articles that evaluated plasma protein levels of IFN-I in mild, severe, or critical COVID-19 patients. Comparative meta-analyses with random effects were performed to compare the standardized mean differences in plasma protein levels of IFN-I of mild versus severe and mild versus critical patients. Meta-regressions were performed to test the moderating role of age, sex, time that the IFN-I was measured, and limit of detection of the assay used in the difference between the means.

Results

There was no significant difference in plasma levels of IFN-α when comparing between mild and severe patients (SMD = -0.236, 95% CI -0.645 to 0.173, p = 0.258, I2 = 82.11), nor when comparing between patients mild and critical (SMD = 0.203, 95% CI -0.363 to 0.770, p = 0.481, I2 = 64.06). However, there was a significant difference between healthy individuals and patients with mild disease (SMD = 0.447, 95% CI 0.085 to 0.810, p = 0.016, I2 = 62.89).

Conclusions

Peripheral IFN-α cannot be used as a severity marker as it does not determine the clinical status presented by COVID-19 patients.

Natural mucosal barriers and COVID-19 in children

BACKGROUND

Coronavirus disease 2019 (COVID-19) is more benign in children compared with adults for unknown reasons. This contrasts with other respiratory viruses where disease manifestations are often more severe in children. We hypothesize that a more robust early innate immune response to SARS coronavirus 2 (SARS-CoV-2) protects against severe disease.

METHODS

Clinical outcomes, SARS-CoV-2 viral copies, and cellular gene expression were compared in nasopharyngeal swabs obtained at the time of presentation to the emergency department from 12 children and 27 adults using bulk RNA sequencing and quantitative reverse-transcription PCR. Total protein, cytokines, and anti–SARS-CoV-2 IgG and IgA were quantified in nasal fluid.

RESULTS

SARS-CoV-2 copies, angiotensin-converting enzyme 2, and TMPRSS2 gene expression were similar in children and adults, but children displayed higher expression of genes associated with IFN signaling, NLRP3 inflammasome, and other innate pathways. Higher levels of IFN-α2, IFN-γ, IP-10, IL-8, and IL-1β protein were detected in nasal fluid in children versus adults. Children also expressed higher levels of genes associated with immune cells, whereas expression of those associated with epithelial cells did not differ in children versus adults. Anti–SARS-CoV-2 IgA and IgG were detected at similar levels in nasal fluid from both groups. None of the children required supplemental oxygen, whereas 7 adults did (P = 0.03); 4 adults died.

CONCLUSION

These findings provide direct evidence of a more vigorous early mucosal immune response in children compared with adults and suggest that this contributes to favorable clinical outcomes.

FUNDING

NIH grants R01 AI134367, UL1 TR002556, T32 AI007501, T32GM007288, P30 AI124414; an Albert Einstein College of Medicine Dean’s COVID-19 Pilot Research Award; and the Eric J. Heyer, MD, PhD Translational Research Pilot Project Award.

SARS-CoV-2 Induced Neurological Manifestations Entangles Cytokine Storm That Implicates For Therapeutic Strategies

The new coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can present with neurological symptoms and induce neurological complications. The involvement in both the central and peripheral nervous systems in COVID-19 patients has been associated with direct invasion of the virus and the induction of cytokine storm. This review discussed the pathways for the virus invasion into the nervous system and characterized the SARS-CoV-2 induced cytokine storm. In addition, the mechanisms underlying the immune responses and cytokine storm induction after SARS-CoV-2 infection were also discussed. Although some neurological symptoms are mild and disappear after recovery from infection, some severe neurological complications contribute to the mortality of COVID-19 patients. Therefore, the insight into the cause of SARS-CoV-2 induced cytokine storm in context with neurological complications will formulate the novel management of the disease and further identify new therapeutic targets for COVID-19.

Type I and III interferon responses in SARS-CoV-2 infection

Coronavirus disease 2019 (COVID-19), the current pandemic disease, is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Type I and III interferons (IFNs) are innate cytokines that are important in the first-line defense against viruses. Similar to many other viruses, SARS-CoV-2 has evolved mechanisms for evading the antiviral effects of type I and III IFNs at multiple levels, including the induction of IFN expression and cellular responses to IFNs. In this review, we describe the innate sensing mechanisms of SARS-CoV-2 and the mechanisms used by SARS-CoV-2 to evade type I and III IFN responses. We also discuss contradictory reports regarding impaired and robust type I IFN responses in patients with severe COVID-19. Finally, we discuss how delayed but exaggerated type I IFN responses can exacerbate inflammation and contribute to the severe progression of COVID-19.

Extensive studies into how SARS-CoV-2 manipulates the immune system and influences the activity of host proteins are needed to improve treatments for COVID-19. SARS-CoV-2 evades or blocks elements of the immune system, including the antiviral activity of type I and type III interferons (IFN). You-Me Kim and Eui-Cheol Shin at the Korea Advanced Institute of Science and Technology, Daejeon, South Korea, reviewed understanding of how SARS-CoV-2 inhibits IFN responses. In infected cells, SARS-CoV-2 proteins use diverse methods to inhibit host IFN pathways, but type I IFN responses are still triggered in non-infected immune cells. The researchers believe this may explain the delayed but exaggerated type I IFN responses that contribute to the hyper-inflammation seen in critically ill patients. They call for further investigations into IFN and inflammatory responses in SARS-CoV-2 infection.

ORAI1 establishes resistance to SARS-CoV-2 infection by regulating tonic type I interferon signaling

ORAI1 and STIM1 are the critical mediators of store-operated Ca²⁺ entry by acting as the pore subunit and an endoplasmic reticulum-resident signaling molecule, respectively. In addition to Ca²⁺ signaling, STIM1 is also involved in regulation of a cytosolic nucleic acid sensing pathway. Using ORAI1 and STIM1 knockout cells, we examined their contribution to the host response to SARS-CoV-2 infection. STIM1 knockout cells showed strong resistance to SARS-CoV-2 infection due to enhanced type I interferon response. On the contrary, ORAI1 knockout cells showed high susceptibility to SARS-CoV-2 infection as judged by increased expression of viral proteins and a high viral load. Mechanistically, ORAI1 knockout cells showed reduced homeostatic cytoplasmic Ca²⁺ concentration and severe impairment in tonic interferon signaling. Transcriptome analysis showed downregulation of multiple cellular defense mechanisms, including antiviral signaling pathways in ORAI1 knockout cells, which are likely due to reduced expression of the Ca²⁺-dependent transcription factors of the activator protein 1 (AP-1) family and MEF2C. Our results identify a novel role of ORAI1-mediated Ca²⁺ signaling in regulating the baseline type I interferon level, which is a determinant of host resistance to SARS-CoV-2 infection.

Epidemiology, pathogenesis, clinical presentations, diagnosis and treatment of COVID-19: a review of current evidence

INTRODUCTION

The COVID-19 pandemic has created a public health crisis, infected millions of people, and caused a significant number of deaths. SARS-CoV-2 transmits from person to person through several routes, mainly via respiratory droplets, which makes it difficult to contain its spread into the community. Here, we provide an overview of the epidemiology, pathogenesis, clinical presentation, diagnosis, and treatment of COVID-19.

AREAS COVERED

Direct person-to-person respiratory transmission has rapidly amplified the spread of coronavirus. In the absence of any clinically proven treatment options, the current clinical management of COVID-19 includes symptom management, infection prevention and control measures, optimized supportive care, and intensive care support in severe or critical illness. Developing an effective vaccine is now a leading research priority. Some vaccines have already been approved by the regulatory authorities for the prevention of COVID-19.

EXPERT OPINION

General prevention and protection measures regarding the containment and management of the second or third waves are necessary to minimize the risk of infection. Until now, four vaccines reported variable efficacies of between 62-95%, and two of them (Pfizer/BioNTech and Moderna) received FDA emergency use authorization. Equitable access and effective distribution of these vaccines in all countries will save millions of lives.

The time to offer treatments for COVID-19

Background: COVID-19 has several overlapping phases. Treatments to date have focused on the late stage of disease in hospital. Yet, the pandemic is by propagated by the viral phase in out-patients. The current public health strategy relies solely on vaccines to prevent disease.Methods: We searched the major national registries, pubmed.org, and the preprint servers for all ongoing, completed and published trial results.Results: As of 2/15/2021, we found 111 publications reporting findings on 14 classes of agents, and 9 vaccines. There were 62 randomized controlled studies, the rest retrospective observational analyses. Only 21 publications dealt with outpatient care. Remdesivir and high titer convalescent plasma have emergency use authorization for hospitalized patients in the U.S.A. There is also support for glucocorticoid treatment of the COVID-19 respiratory distress syndrome. Monoclonal antibodies are authorized for outpatients, but supply is inadequate to treat all at time of diagnosis. Favipiravir, ivermectin, and interferons are approved in certain countries.Expert Opinion: Vaccines and antibodies are highly antigen specific, and new SARS-Cov-2 variants are appearing. We call on public health authorities to authorize treatments with known low-risk and possible benefit for outpatients in parallel with universal vaccination.

Potential role of IFN-α in COVID-19 patients and its underlying treatment options

The coronavirus disease (COVID-19) caused by a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly worldwide. Given that this contagious viral outbreak is still unfolding, it is urgent to understand the pathogenesis of SARS-CoV-2 infection and explore effective treatments to protect patients from developing a severe illness related to COVID-19. Recently, IFN-α has been considered a potential therapeutic strategy to treat COVID-19 disease, mainly because the innate immune system rapidly produces IFN-α as the first line of defense to combat viral infections. However, IFN-α can also play a role in immunoregulatory effects, causing pathogenic damage and uncontrolled inflammatory responses. There are 13 human IFN-α subtypes that bind to the same receptor and induce different interferon-stimulated gene (ISG) expression, regulating various antiviral and immunoregulatory effects. The varying degrees of inflammatory regulations may raise concerns about the possible side effects to enlarge the inflammatory responses, exacerbating the severity of infection. Thus, the analysis of various IFN-α subtype induction during SARS-CoV-2 infection is necessary in exploring the mechanism of COVID-19 pathogenesis. This review summarizes the current understanding of IFN-α in the pathogenesis of respiratory virus diseases and IFN-α based clinical intervention used in SARS-CoV-2 infection and other respiratory virus diseases. Besides, new ideas in selecting suitable IFN-α subtypes or combinations as drug candidates for viral infection treatment will also be discussed.Key Points• IFN-α plays an important role in anti-viral and immunoregulatory effects in COVID-19 patients caused by SARS-CoV-2.• The uncontrolled inflammation and disease severity correlated to the diversity of IFN-α subtype induction.• Selecting suitable IFN-α subtypes or combinations as drug candidates will be beneficial for the treatment of patients with COVID-19.

Roles of Type I and III Interferons in COVID-19

Coronavirus disease 2019 (COVID-19) is an ongoing global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Type I and III interferon (IFN) responses act as the first line of defense against viral infection and are activated by the recognition of viruses by infected cells and innate immune cells. Dysregulation of host IFN responses has been known to be associated with severe disease progression in COVID-19 patients. However, the reported results are controversial and the roles of IFN responses in COVID-19 need to be investigated further. In the absence of a highly efficacious antiviral drug, clinical studies have evaluated recombinant type I and III IFNs, as they have been successfully used for the treatment of infections caused by two other epidemic coronaviruses, SARS-CoV-1 and Middle East respiratory syndrome (MERS)-CoV. In this review, we describe the strategies by which SARS-CoV-2 evades IFN responses and the dysregulation of host IFN responses in COVID-19 patients. In addition, we discuss the therapeutic potential of type I and III IFNs in COVID-19.

Current COVID-19 treatments: Rapid review of the literature

BACKGROUND

As SARS-CoV-2 continues to spread worldwide, it has already resulted in over 110 million cases and 2.5 million deaths. Currently, there are no effective COVID-19 treatments, although numerous studies are under way. SARS-CoV-2, however, is not the first coronavirus to cause serious outbreaks. COVID-19 can be compared with previous human coronavirus diseases, such as Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS), to better understand the development of treatments.

METHODS

Databases Medline, Embase and WHO COVID-19 was systematically searched on 9 February 2021 for studies reporting on therapeutic effect of COVID-19 treatments. Clinical trials, case reports, observational studies and systematic reviews in the English language were eligible.

RESULTS

1416 studies were identified and 40 studies were included in this review. Therapies included are: remdesivir, convalescent plasma, hydroxychloroquine, lopinavir/ ritonavir, interferon, corticosteroids, cytokine storm inhibitors and monoclonal antibodies. Remdesivir, convalescent plasma and interferon seems to provide some clinical benefits such as faster recovery time and reduced mortality, but these effects are not clinically significant. Some corticosteroids are effective in reducing mortality in severe COVID-19 patients. Hydroxychloroquine do not convey any beneficial, and therapies such as cytokine storm inhibitors and monoclonal antibodies were also not effective and require further investigation.

CONCLUSIONS

There is no single therapy effective against COVID-19. However, a combination of therapies administered at different stages of infection may provide some benefit. This conclusion is reflected in the limited effects of these treatments in previous human coronaviruses.

The therapeutic effect and safety of the drugs for COVID-19: A systematic review and meta-analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19) has spread almost all regions of the world and caused great loss to the whole body of mankind. Thus, numerous clinical trials were conducted to find specific medicine for COVID-19 recently. However, it remains unanswered whether they are beneficial.

OBJECTIVE

This study aimed to evaluate the efficiency and safety of the COVID-19 medicine.

METHODS

Studies were determined through searching PubMed, Embase, Cochrane Library, and Medline. The studies of COVID-19 medicine were involved with eligible end points containing mortality, discharge rate, rate of clinical improvement, and rate of serious adverse events.

RESULTS

A total of 33 studies involving 37,879 patients were included in our study, whose intervening measures contained three major types of COVID-19 medicine, ACEI/ARB, antiviral medicine, and chloroquine/hydroxychloroquine. Compared to control group, COVID-19 drugs have no distinct effect on mortality (RR, 0.93; 95% CI, 0.79-1.11, P = .43) and discharge rate (RR, 1.06; 95% CI, 0.98-1.14, P = .13). However, antiviral medicine presents the obvious advantage in clinical improvement (RR, 1.11; 95% CI, 1.01-1.23, P < .05). In addition, the serious adverse events rate (RR, 0.75; 95% CI, 0.63-0.88, P < .05) of COVID-19 medicine is lower than control group.

CONCLUSION

The results indicated antiviral medicine was potential specific medicine for COVID-19 treatment by improving clinical symptoms, but it failed to increase the discharge rate and reduce mortality. Chloroquine/hydroxychloroquine and ACEI/ARB had no significant effect on treatment of COVID-19, thus they were not recommended for routine medication. Moreover, more trials are needed to find effective drugs to lower the mortality of COVID-19 patients.

The therapeutic potential of inorganic polyphosphate: A versatile physiological polymer to control coronavirus disease (COVID-19)

Rationale: The pandemic caused by the novel coronavirus SARS-CoV-2 is advancing rapidly. In particular, the number of severe courses of the disease is still dramatically high. An efficient drug therapy that helps to improve significantly the fatal combination of damages in the airway epithelia, in the extensive pulmonary microvascularization and finally multiorgan failure, is missing. The physiological, inorganic polymer, polyphosphate (polyP) is a molecule which could prevent the initial phase of the virus life cycle, the attachment of the virus to the target cells, and improve the epithelial integrity as well as the mucus barrier. Results: Surprisingly, polyP matches perfectly with the cationic groove on the RBD. Subsequent binding studies disclosed that polyP, with a physiological chain length of 40 phosphate residues, abolishes the binding propensity of the RBD to the ACE2 receptor. In addition to this first mode of action of polyP, this polymer causes in epithelial cells an increased gene expression of the major mucins in the airways, of MUC5AC and MUC1, as well as a subsequent glycoprotein production. MUC5AC forms a gel-like mucus layer trapping inhaled particles which are then transported out of the airways, while MUC1 constitutes the periciliary liquid layer and supports ciliary beating. As a third mode of action, polyP undergoes enzymatic hydrolysis of the anhydride bonds in the airway system by alkaline phosphatase, releasing metabolic energy. Conclusions: This review summarizes the state of the art of the biotherapeutic potential of the polymer polyP and the findings from basic research and outlines future biomedical applications.

Virus Caused Imbalance of Type I IFN Responses and Inflammation in COVID-19

The global expansion of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as one of the greatest public health challenges and imposes a great threat to human health. Innate immunity plays vital roles in eliminating viruses through initiating type I interferons (IFNs)-dependent antiviral responses and inducing inflammation. Therefore, optimal activation of innate immunity and balanced type I IFN responses and inflammation are beneficial for efficient elimination of invading viruses. However, SARS-CoV-2 manipulates the host's innate immune system by multiple mechanisms, leading to aberrant type I IFN responses and excessive inflammation. In this review, we will emphasize the recent advances in the understanding of the crosstalk between host innate immunity and SARS-CoV-2 to explain the imbalance between inflammation and type I IFN responses caused by viral infection, and explore potential therapeutic targets for COVID-19.

Management of hospitalised adults with coronavirus disease 2019 (COVID-19): a European Respiratory Society living guideline

INTRODUCTION

Hospitalised patients with coronavirus disease 2019 (COVID-19) as a result of SARS-CoV-2 infection have a high mortality rate and frequently require noninvasive respiratory support or invasive ventilation. Optimising and standardising management through evidence-based guidelines may improve quality of care and therefore patient outcomes.

METHODS

A task force from the European Respiratory Society and endorsed by the Chinese Thoracic Society identified priority interventions (pharmacological and non-pharmacological) for the initial version of this "living guideline" using the PICO (population, intervention, comparator, outcome) format. The GRADE approach was used for assessing the quality of evidence and strength of recommendations. Systematic literature reviews were performed, and data pooled by meta-analysis where possible. Evidence tables were presented and evidence to decision frameworks were used to formulate recommendations.

RESULTS

Based on the available evidence at the time of guideline development (20 February, 2021), the panel makes a strong recommendation in favour of the use of systemic corticosteroids in patients requiring supplementary oxygen or ventilatory support, and for the use of anticoagulation in hospitalised patients. The panel makes a conditional recommendation for interleukin (IL)-6 receptor antagonist monoclonal antibody treatment and high-flow nasal oxygen or continuous positive airway pressure in patients with hypoxaemic respiratory failure. The panel make strong recommendations against the use of hydroxychloroquine and lopinavir-ritonavir. Conditional recommendations are made against the use of azithromycin, hydroxychloroquine combined with azithromycin, colchicine, and remdesivir, in the latter case specifically in patients requiring invasive mechanical ventilation. No recommendation was made for remdesivir in patients requiring supplemental oxygen. Further recommendations for research are made.

CONCLUSION

The evidence base for management of COVID-19 now supports strong recommendations in favour and against specific interventions. These guidelines will be regularly updated as further evidence becomes available.

Bridging animal and clinical research during SARS-CoV-2 pandemic: A new-old challenge

Many milestones in medical history rest on animal modeling of human diseases. The SARS-CoV-2 pandemic has evoked a tremendous investigative effort primarily centered on clinical studies. However, several animal SARS-CoV-2/COVID-19 models have been developed and pre-clinical findings aimed at supporting clinical evidence rapidly emerge. In this review, we characterize the existing animal models exposing their relevance and limitations as well as outline their utility in COVID-19 drug and vaccine development. Concurrently, we summarize the status of clinical trial research and discuss the novel tactics utilized in the largest multi-center trials aiming to accelerate generation of reliable results that may subsequently shape COVID-19 clinical treatment practices. We also highlight areas of improvement for animal studies in order to elevate their translational utility. In pandemics, to optimize the use of strained resources in a short time-frame, optimizing and strengthening the synergy between the preclinical and clinical domains is pivotal.

Quality and consistency of clinical practice guidelines for treating children with COVID-19

Background

The Coronavirus Disease 2019 (COVID-19) pandemic negatively affects children’s health. Many guidelines have been developed for treating children with COVID-19. The quality of the existing guidelines and the consistency of recommendations remains unknown. Therefore, we aim to review the clinical practice guidelines (CPGs) for children with COVID-19 systematically.

Methods

We systematically searched Medline, Embase, guideline-related websites, and Google. The Appraisal of Guidelines for Research and Evaluation II (AGREE II) tool and Reporting Items for practice Guidelines in HealThcare (RIGHT) checklist were used to evaluate the methodological and reporting quality of the included guidelines, respectively. The consistency of recommendations across the guidelines and their supporting evidence were analyzed.

Results

Twenty guidelines were included in this study. The mean AGREE II score and mean RIGHT reporting rate of the included guidelines were 37% (range, 22–62%) and 52% (range, 31–89%), respectively. As for methodological quality, no guideline was classified as high, one guideline (5%) moderate, and 19 (95%) low. In terms of reporting quality, one guideline (5%) was rated as high, 12 guidelines (60%) moderate, and seven (35%) low. Among included guidelines, recommendations varied greatly in the use of remdesivir (recommend: 25%, not recommend: 45%, not report: 30%), interferon (recommend: 15%, not recommend: 50%, not report: 35%), glucocorticoids (recommend: 50%, not recommend: 20%, not report: 30%), and intravenous immune globulin (recommend: 35%, not recommend: 30%, not report: 35%). None of the guidelines cited clinical trials from children with COVID-19.

Conclusions

The methodological and reporting quality of guidelines for treating children with COVID-19 was not high. Recommendations were inconsistent across different guidelines. The supporting evidence from children with COVID-19 was very limited.

The first 12 months of COVID-19: a timeline of immunological insights

Since the initial reports of a cluster of pneumonia cases of unidentified origin in Wuhan, China, in December 2019, the novel coronavirus that causes this disease - severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) - has spread throughout the world, igniting the twenty-first century's deadliest pandemic. Over the past 12 months, a dizzying array of information has emerged from numerous laboratories, covering everything from the putative origin of SARS-CoV-2 to the development of numerous candidate vaccines. Many immunologists quickly pivoted from their existing research to focus on coronavirus disease 2019 (COVID-19) and, owing to this unprecedented convergence of efforts on one viral infection, a remarkable body of work has been produced and disseminated, through both preprint servers and peer-reviewed journals. Here, we take readers through the timeline of key discoveries during the first year of the pandemic, which showcases the extraordinary leaps in our understanding of the immune response to SARS-CoV-2 and highlights gaps in our knowledge as well as areas for future investigations.

Overlapping and distinct features of viral and allergen immunity in the human lung

Immunity in the human respiratory tract is provided by a diverse range of tissue-resident cells, including specialized epithelial and macrophage populations and a network of innate and innate-like lymphocytes, such as natural killer cells, innate lymphoid cells, and invariant T cells. Lung-resident memory T and B cells contribute to this network following initial exposure to antigenic stimuli. This review explores how advances in the study of human immunology have shaped our understanding of this resident immune network and its response to two of the most commonly encountered inflammatory stimuli in the airways: viruses and allergens. It discusses the many ways in which pathogenic infection and allergic inflammation mirror each other, highlighting the key checkpoints at which they diverge and how this can result in a lifetime of allergic exacerbation versus protective anti-viral immunity.

Why Do Some People Develop Serious COVID-19 Disease After Infection, While Others Only Exhibit Mild Symptoms?

The year 2020 was a landmark year of a once-in-a-century pandemic of a novel coronavirus, SARS-CoV-2 virus, that led to a rapidly spreading coronavirus disease (COVID-19). The spectrum of disease with SARS-CoV-2 ranges from asymptomatic to mild upper respiratory illness, to moderate to severe disease with respiratory compromise to acute respiratory distress syndrome, multiorgan failure, and death. Early in the pandemic, risk factors were recognized that contributed to more severe disease, but it became evident that individuals and even young people could have severe COVID-19. As we started to understand the immunobiology of COVID-19, it became clearer that the immune responses to SARS-CoV-2 were variable, and in some cases, the excessive inflammatory response contributed to greater morbidity and mortality. In this review, we will explore some of the additional risk factors that appear to contribute to disease severity and enhance our understanding of why some individuals experience more severe COVID-19. Recent advances in genome-wide associations have identified potential candidate genes in certain populations that may modify the host immune responses leading to dysregulated host immunity. Genetic defects of the type I interferon pathway are also linked to a more clinically severe phenotype of COVID-19. Finally, dysregulation of the adaptive immune system may also play a role in the severity and complex clinical course of patients with COVID-19. A better understanding of the host immune responses to SARS-CoV-2 will hopefully lead to new treatment modalities to prevent the poor outcomes of COVID-19 in those individuals with pre-existing risk factors or genetic variants that contribute to the dysregulated host immune responses.

Peginterferon Lambda-1a for treatment of outpatients with uncomplicated COVID-19: a randomized placebo-controlled trial

Type III interferons have been touted as promising therapeutics in outpatients with coronavirus disease 2019 (COVID-19). We conducted a randomized, single-blind, placebo-controlled trial (NCT04331899) in 120 outpatients with mild to moderate COVID-19 to determine whether a single, 180 mcg subcutaneous dose of Peginterferon Lambda-1a (Lambda) within 72 hours of diagnosis could shorten the duration of viral shedding (primary endpoint) or symptoms (secondary endpoint). In both the 60 patients receiving Lambda and 60 receiving placebo, the median time to cessation of viral shedding was 7 days (hazard ratio [HR] = 0.81; 95% confidence interval [CI] 0.56 to 1.19). Symptoms resolved in 8 and 9 days in Lambda and placebo, respectively, and symptom duration did not differ significantly between groups (HR 0.94; 95% CI 0.64 to 1.39). Both Lambda and placebo were well-tolerated, though liver transaminase elevations were more common in the Lambda vs. placebo arm (15/60 vs 5/60; p = 0.027). In this study, a single dose of subcutaneous Peginterferon Lambda-1a neither shortened the duration of SARS-CoV-2 viral shedding nor improved symptoms in outpatients with uncomplicated COVID-19.

BTK inhibitors for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): A Systematic Review

ImportanceThe Bruton tyrosine kinase (BTK) regulates B cell and macrophage signaling, development, survival, and activation. BTK inhibition was shown to protect against lethal influenza-induced acute lung injury in mice. Inhibiting BTK has been hypothesized to ameliorate lung injury in patients with severe coronavirus disease 2019 (COVID-19). ObjectiveTo evaluate the use of BTK inhibitors (BTKinibs) during COVID-19 and assess how they may affect patient outcomes.Evidence ReviewWe searched PubMed, Embase, and Web of Science: Core on December 30, 2020. Clinical studies with at least 5 COVID-19 patients treated with BTKinibs were included. Case reports and reviews were excluded.FindingsOne hundred twenty-five articles were identified, 6 of which met inclusion criteria. Sample size ranged from 6 to 126 patients. Patient populations included subjects hospitalized with COVID-19 (6/6) and admitted to the intensive care unit (5/6). Patient age ranged between 35 and 98 years. Four studies included patients already receiving BTKinibs for their lymphoproliferative disease, 1 for Waldenstrom's macroglobulinemia and 3 for chronic lymphocytic leukemia (CLL). The most common clinical outcomes measured were oxygen requirements (4/6) and hospitalization rate or duration (3/6). Differences in standard-of-care reflected the date of study and pre-existing conditions in the various patient cohorts. Full-dose acalabrutinib was evaluated in 2 studies, one study evaluated full-dose ibrutinib, and another study evaluated both ibrutinib and acalabrutinib. The remainder 2 studies described outcomes in CLL patients on multiple BTKinibs and other CLL-targeted treatments. Three studies showed decreased oxygen requirements in patients who started or continued BTKinibs. All three studies that evaluated hospitalization rate or duration found favorable outcomes in those on BTKinibs. Conclusions and RelevanceBTKinib use was associated with decreased oxygen requirements and decreased hospitalization rates and duration. However, randomized clinical trials are needed to validate the beneficial effects of BTKinibs for acute SARS-CoV-2 infection.

Nanotechnology advances in pathogen- and host-targeted antiviral delivery: multipronged therapeutic intervention for pandemic control

The COVID-19 pandemic's high mortality rate and severe socioeconomic impact serve as a reminder of the urgent need for effective countermeasures against viral pandemic threats. In particular, effective antiviral therapeutics capable of stopping infections in its tracks is critical to reducing infection fatality rate and healthcare burden. With the field of drug delivery witnessing tremendous advancement in the last two decades owing to a panoply of nanotechnology advances, the present review summarizes and expounds on the research and development of therapeutic nanoformulations against various infectious viral pathogens, including HIV, influenza, and coronaviruses. Specifically, nanotechnology advances towards improving pathogen- and host-targeted antiviral drug delivery are reviewed, and the prospect of achieving effective viral eradication, broad-spectrum antiviral effect, and resisting viral mutations are discussed. As several COVID-19 antiviral clinical trials are met with lackluster treatment efficacy, nanocarrier strategies aimed at improving drug pharmacokinetics, biodistributions, and synergism are expected to not only contribute to the current disease treatment efforts but also expand the antiviral arsenal against other emerging viral diseases.

Endogenously Produced SARS-CoV-2 Specific IgG Antibodies May Have a Limited Impact on Clearing Nasal Shedding of Virus during Primary Infection in Humans

While SARS-CoV-2 specific neutralizing antibodies have been developed for therapeutic purposes, the specific viral triggers that drive the generation of SARS-CoV-2 specific IgG and IgM antibodies remain only partially characterized. Moreover, it is unknown whether endogenously derived antibodies drive viral clearance that might result in mitigation of clinical severity during natural infection. We developed a series of non-linear mathematical models to investigate whether SARS-CoV-2 viral and antibody kinetics are coupled or governed by separate processes. Patients with severe disease had a higher production rate of IgG but not IgM antibodies. Maximal levels of both isotypes were governed by their production rate rather than different saturation levels between people. Our results suggest that an exponential surge in IgG levels occurs approximately 5-10 days after symptom onset with no requirement for continual antigenic stimulation. SARS-CoV-2 specific IgG antibodies appear to have limited to no effect on viral dynamics but may enhance viral clearance late during primary infection resulting from the binding effect of antibody to virus, rather than neutralization. In conclusion, SARS-CoV-2 specific IgG antibodies may play only a limited role in clearing infection from the nasal passages despite providing long-term immunity against infection following vaccination or prior infection.

Current evidence for COVID-19 therapies: a systematic literature review

Effective therapeutic interventions for the treatment and prevention of coronavirus disease 2019 (COVID-19) are urgently needed. A systematic review was conducted to identify clinical trials of pharmacological interventions for COVID-19 published between 1 December 2019 and 14 October 2020. Data regarding efficacy of interventions, in terms of mortality, hospitalisation and need for ventilation, were extracted from identified studies and synthesised qualitatively. In total, 42 clinical trials were included. Interventions assessed included antiviral, mucolytic, antimalarial, anti-inflammatory and immunomodulatory therapies. Some reductions in mortality, hospitalisation and need for ventilation were seen with interferons and remdesivir, particularly when administered early, and with the mucolytic drug, bromhexine. Most studies of lopinavir/ritonavir and hydroxychloroquine did not show significant efficacy over standard care/placebo. Dexamethasone significantly reduced mortality, hospitalisation and need for ventilation versus standard care, particularly in patients with severe disease. Evidence for other classes of interventions was limited. Many trials had a moderate-to-high risk of bias, particularly in terms of blinding; most were short-term and some included low patient numbers.This review highlights the need for well-designed clinical trials of therapeutic interventions for COVID-19 to increase the quality of available evidence. It also emphasises the importance of tailoring interventions to disease stage and severity for maximum efficacy.

Blood Interferon-α Levels and Severity, Outcomes, and Inflammatory Profiles in Hospitalized COVID-19 Patients

Background: Deficient interferon responses have been proposed as one of the relevant mechanisms prompting severe manifestations of COVID-19.

Objective: To evaluate the interferon (IFN)-α levels in a cohort of COVID-19 patients in relation to severity, evolution of the clinical manifestations and immune/inflammatory profile.

Methods: This is prospective study recruiting consecutive hospitalized patients with respiratory failure associated with SARS-COV-2 infection and matched controls. After enrollment, patients were assessed every 7 ± 2 days for additional 2 consecutive visits, for a total of 21 days. The severity of the clinical condition was ranked based on the level of respiratory support required. At each time-point blood samples were obtained to assess immune cells and mediators by multiplex immunoassay.

Results: Fifty-four COVD-19 and 11 control patients matched for severity were enrolled. At recruitment, lower levels of blood IFN-α were found in COVID-19 patients compared to controls (3.8-fold difference, p < 0.01). Improvements in COVID-19 severity were paralleled by a significant increase of blood IFN-α levels. A significant increase in blood IFN-α was found over the study period in survivors (70% of the study population). A similar trend was found for blood IFN-β with IFN-β levels below the threshold of detectability in a substantial proportion of subjects. Significantly higher values of blood lymphocytes and lower levels of IL-10 were found at each time point in patients who survived compared to patients who died. In patients who clinically improved and survived during the study, we found an inverse association between IL-10 and IFN-α levels.

Conclusion: The study identifies a blood immune profile defined by deficient IFN-α levels associated with increased IL-10 expression in patients progressing to severe/life threatening COVID-19 conditions, suggesting the involvement of immunological pathways that could be target of pharmacological intervention.

Clinical Trial Registration:ClinicalTrials.gov identifier NCT04343053.

Identification and Development of Therapeutics for COVID-19

After emerging in China in late 2019, the novel coronavirus SARS-CoV-2 spread worldwide and as of mid-2021 remains a significant threat globally. Only a few coronaviruses are known to infect humans, and only two cause infections similar in severity to SARS-CoV-2: Severe acute respiratory syndrome-related coronavirus, a closely related species of SARS-CoV-2 that emerged in 2002, and Middle East respiratory syndrome-related coronavirus, which emerged in 2012. Unlike the current pandemic, previous epidemics were controlled rapidly through public health measures, but the body of research investigating severe acute respiratory syndrome and Middle East respiratory syndrome has proven valuable for identifying approaches to treating and preventing novel coronavirus disease 2019 (COVID-19). Building on this research, the medical and scientific communities have responded rapidly to the COVID-19 crisis to identify many candidate therapeutics. The approaches used to identify candidates fall into four main categories: adaptation of clinical approaches to diseases with related pathologies, adaptation based on virological properties, adaptation based on host response, and data-driven identification of candidates based on physical properties or on pharmacological compendia. To date, a small number of therapeutics have already been authorized by regulatory agencies such as the Food and Drug Administration (FDA), while most remain under investigation. The scale of the COVID-19 crisis offers a rare opportunity to collect data on the effects of candidate therapeutics. This information provides insight not only into the management of coronavirus diseases, but also into the relative success of different approaches to identifying candidate therapeutics against an emerging disease.

Clinical evidence of an interferon-glucocorticoid therapeutic synergy in COVID-19

Synthetic glucocorticoid dexamethasone is the first trial-proven drug that reduces COVID-19 mortality by suppressing immune system. In contrast, interferons are a crucial component of host antiviral immunity and can be directly suppressed by glucocorticoids. To investigate whether therapeutic interferons can compensate glucocorticoids-induced loss of antiviral immunity, we retrospectively analyzed a cohort of 387 PCR-confirmed COVID-19 patients with quasi-random exposure to interferons and conditional exposure to glucocorticoids. Among patients receiving glucocorticoids, early interferon therapy was associated with earlier hospital discharge (adjusted HR 1.68, 95% CI 1.19-2.37) and symptom relief (adjusted HR 1.48, 95% CI 1.06-2.08), while these associations were insignificant among glucocorticoids nonusers. Early interferon therapy was also associated with lower prevalence of prolonged viral shedding (adjusted OR 0.24, 95% CI 0.10-0.57) only among glucocorticoids users. Additionally, these associations were glucocorticoid cumulative dose- and timing-dependent. These findings reveal potential therapeutic synergy between interferons and glucocorticoids in COVID-19 that warrants further investigation.

Revised Korean Society of Infectious Diseases/National Evidence-based Healthcarea Collaborating Agency Guidelines on the Treatment of Patients with COVID-19

Despite the global effort to mitigate the spread, coronavirus disease 2019 (COVID-19) has become a pandemic that took more than 2 million lives. There are numerous ongoing clinical studies aiming to find treatment options and many are being published daily. Some effective treatment options, albeit of variable efficacy, have been discovered. Therefore, it is necessary to develop an evidence-based methodology, to continuously check for new evidence, and to update recommendations accordingly. Here we provide guidelines on pharmaceutical treatment for COVID-19 based on the latest evidence.

Respiratory delivery of favipiravir-tocilizumab combination through mucoadhesive protein-lipidic nanovesicles: prospective therapeutics against COVID-19

Coronavirus disease 19 (COVID-19) is the prime global health concern of the year 2020. Infecting more than 112 million individuals so far, this pandemic has already reported more than 2.4 million deaths around the world. With such high infectivity and mortality, effective treatment intervention is the need of the hour. The integration of medical science with nanotechnology may solve the current problem by exploring collective benefits. In this manuscript, we theoretically proposed the duo-combination of an approved antiviral i.e. favipiravir along with an immunomodulator i.e. tocilizumab loaded in protein-lipid nanovesicles as an effective anti-COVID-19 therapeutic. This proposed nanomedicine delivered through the respiratory mode may enhance the effectiveness of the antiviral and help in restricting the virus and associated complications, utilizing both anti-viral activity and immunomodulation in COVID-19 patients. This proposed nanomedicine could be an effective treatment modality for the severe acute respiratory syndrome- coronavirus-2 (SARS-CoV-2) infected patients.

A quantitative model used to compare within-host SARS-CoV-2, MERS-CoV, and SARS-CoV dynamics provides insights into the pathogenesis and treatment of SARS-CoV-2

The scientific community is focused on developing antiviral therapies to mitigate the impacts of the ongoing novel coronavirus disease 2019 (COVID-19) outbreak. This will be facilitated by improved understanding of viral dynamics within infected hosts. Here, using a mathematical model in combination with published viral load data, we compare within-host viral dynamics of SARS-CoV-2 with analogous dynamics of MERS-CoV and SARS-CoV. Our quantitative analyses using a mathematical model revealed that the within-host reproduction number at symptom onset of SARS-CoV-2 was statistically significantly larger than that of MERS-CoV and similar to that of SARS-CoV. In addition, the time from symptom onset to the viral load peak for SARS-CoV-2 infection was shorter than those of MERS-CoV and SARS-CoV. These findings suggest the difficulty of controlling SARS-CoV-2 infection by antivirals. We further used the viral dynamics model to predict the efficacy of potential antiviral drugs that have different modes of action. The efficacy was measured by the reduction in the viral load area under the curve (AUC). Our results indicate that therapies that block de novo infection or virus production are likely to be effective if and only if initiated before the viral load peak (which appears 2-3 days after symptom onset), but therapies that promote cytotoxicity of infected cells are likely to have effects with less sensitivity to the timing of treatment initiation. Furthermore, combining a therapy that promotes cytotoxicity and one that blocks de novo infection or virus production synergistically reduces the AUC with early treatment. Our unique modeling approach provides insights into the pathogenesis of SARS-CoV-2 and may be useful for development of antiviral therapies.

Impaired local intrinsic immunity to SARS-CoV-2 infection in severe COVID-19

Infection with SARS-CoV-2, the virus that causes COVID-19, can lead to severe lower respiratory illness including pneumonia and acute respiratory distress syndrome, which can result in profound morbidity and mortality. However, many infected individuals are either asymptomatic or have isolated upper respiratory symptoms, which suggests that the upper airways represent the initial site of viral infection, and that some individuals are able to largely constrain viral pathology to the nasal and oropharyngeal tissues. Which cell types in the human nasopharynx are the primary targets of SARS-CoV-2 infection, and how infection influences the cellular organization of the respiratory epithelium remains incompletely understood. Here, we present nasopharyngeal samples from a cohort of 35 individuals with COVID-19, representing a wide spectrum of disease states from ambulatory to critically ill, as well as 23 healthy and intubated patients without COVID-19. Using standard nasopharyngeal swabs, we collected viable cells and performed single-cell RNA-sequencing (scRNA-seq), simultaneously profiling both host and viral RNA. We find that following infection with SARS-CoV-2, the upper respiratory epithelium undergoes massive reorganization: secretory cells diversify and expand, and mature epithelial cells are preferentially lost. Further, we observe evidence for deuterosomal cell and immature ciliated cell expansion, potentially representing active repopulation of lost ciliated cells through coupled secretory cell differentiation. Epithelial cells from participants with mild/moderate COVID-19 show extensive induction of genes associated with anti-viral and type I interferon responses. In contrast, cells from participants with severe lower respiratory symptoms appear globally muted in their anti-viral capacity, despite substantially higher local inflammatory myeloid populations and equivalent nasal viral loads. This suggests an essential role for intrinsic, local epithelial immunity in curbing and constraining viral-induced pathology. Using a custom computational pipeline, we characterized cell-associated SARS-CoV-2 RNA and identified rare cells with RNA intermediates strongly suggestive of active replication. Both within and across individuals, we find remarkable diversity and heterogeneity among SARS-CoV-2 RNA+ host cells, including developing/immature and interferon-responsive ciliated cells, KRT13+ "hillock"-like cells, and unique subsets of secretory, goblet, and squamous cells. Finally, SARS-CoV-2 RNA+ cells, as compared to uninfected bystanders, are enriched for genes involved in susceptibility (e.g., CTSL, TMPRSS2) or response (e.g., MX1, IFITM3, EIF2AK2) to infection. Together, this work defines both protective and detrimental host responses to SARS-CoV-2, determines the direct viral targets of infection, and suggests that failed anti-viral epithelial immunity in the nasal mucosa may underlie the progression to severe COVID-19.

The COVID-19 Treatment Landscape: A South African Perspective on a Race Against Time

The pandemic caused by SARS-CoV-2 has infected more than 94 million people worldwide (as of 17 January 2020). Severe disease is believed to be secondary to the cytokine release syndrome (CRS or "cytokine storm") which causes local tissue damage as well as multi-organ dysfunction and thrombotic complications. Due to the high mortality rates in patients receiving invasive ventilation, practice has changed from "early-intubation" for acute respiratory distress syndrome (ARDS) to a trial of non-invasive ventilation (NIV) or high flow nasal cannula (HFNC) oxygen. Reports indicating the benefit of NIV and HFNC have been encouraging and have led to more than 20,000 such devices being manufactured and ready for roll-out in South Africa (SA) as of July 2020. The need to identify drugs with clear clinical benefits has led to an array of clinical trials, most of which are repurposing drugs for COVID-19. The treatment landscape reflects the need to target both the virus and its effects such as the CRS and thrombotic complications. Conflicting results have the potential to confuse the implementation of coordinated treatment strategies and guidelines. The purpose of this review is to address pertinent areas in the current literature on the available medical treatment options for COVID-19. Remdesivir, tocilizumab, and dexamethasone are some of the treatment options that have shown the most promise, but further randomized trials are required to particularly address timing and dosages to confidently create standardized protocols. For the SA population, two healthcare sectors exist. In the private sector, patients with medical insurance may have greater access to a wider range of treatment options than those in the public sector. The latter serves >80% of the population, and resource constraints require the identification of drugs with the most cost-effective use for the greatest number of affected patients.

Natural Mucosal Barriers and COVID-19 in Children

COVID-19 is more benign in children compared to adults for unknown reasons. This contrasts with viruses such as influenza where disease manifestations are often more severe in children1. We hypothesized that a more robust early innate immune response to SARS-CoV-2 may protect against severe disease and compared clinical outcomes, viral copies and cellular gene and protein expression in nasopharyngeal swabs from 12 children and 27 adults upon presentation to the Emergency Department. SARS-CoV-2 copies were similar, but compared to adults, children displayed higher expression of genes associated with interferon signaling, NLRP3 inflammasome, and other innate pathways. Higher levels of IFN-alpha2, IFN-gamma, IP-10, IL-8, and IL-1beta were detected in nasal fluid in children versus adults. Anti-SARS-CoV-2 IgA and IgG were detected in nasal fluid from both groups and correlated negatively with mucosal IL-18. These findings suggest that a more robust innate immune response in children compared to adults contributes to favorable clinical outcomes.

Peginterferon lambda for the treatment of outpatients with COVID-19: a phase 2, placebo-controlled randomised trial

BACKGROUND

To date, only monoclonal antibodies have been shown to be effective for outpatients with COVID-19. Interferon lambda-1 is a type III interferon involved in innate antiviral responses with activity against respiratory pathogens. We aimed to investigate the safety and efficacy of peginterferon lambda in the treatment of outpatients with mild-to-moderate COVID-19.

METHODS

In this double-blind, placebo-controlled trial, outpatients with laboratory-confirmed COVID-19 were randomly assigned to a single subcutaneous injection of peginterferon lambda 180 μg or placebo within 7 days of symptom onset or first positive swab if asymptomatic. Participants were randomly assigned (1:1) using a computer-generated randomisation list created with a randomisation schedule in blocks of four. At the time of administration, study nurses received a sealed opaque envelope with the treatment allocation number. The primary endpoint was the proportion of patients who were negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA on day 7 after the injection, analysed by a χ² test following an intention-to-treat principle. Prespecified analysis of the primary endpoint, adjusted for baseline viral load, using bivariate logistic regression was done. The trial is now complete. This trial is registered with ClinicalTrials.gov, NCT04354259.

FINDINGS

Between May 18, and Sept 4, 2020, we recruited 30 patients per group. The decline in SARS-CoV-2 RNA was greater in those treated with peginterferon lambda than placebo from day 3 onwards, with a difference of 2·42 log copies per mL at day 7 (p=0·0041). By day 7, 24 (80%) participants in the peginterferon lambda group had an undetectable viral load, compared with 19 (63%) in the placebo group (p=0·15). After controlling for baseline viral load, patients in the peginterferon lambda group were more likely to have undetectable virus by day 7 than were those in the placebo group (odds ratio [OR] 4·12 [95% CI 1·15-16·73; p=0·029). Of those with baseline viral load above 10⁶ copies per mL, 15 (79%) of 19 patients in the peginterferon lambda group had undetectable virus on day 7, compared with six (38%) of 16 in the placebo group (OR 6·25 [95% CI 1·49-31·06]; p=0·012). Peginterferon lambda was well tolerated, and adverse events were similar between groups with mild and transient aminotransferase, concentration increases more frequently observed in the peginterferon lambda group. Two individuals met the threshold of grade 3 increase, one in each group, and no other grade 3 or 4 laboratory adverse events were reported.

INTERPRETATION

Peginterferon lambda accelerated viral decline in outpatients with COVID-19, increasing the proportion of patients with viral clearance by day 7, particularly in those with high baseline viral load. Peginterferon lambda has potential to prevent clinical deterioration and shorten duration of viral shedding.

FUNDING

The Toronto COVID-19 Action Initiative, University of Toronto, and the Ontario First COVID-19 Rapid Research Fund, Toronto General & Western Hospital Foundation.

A novel ACE2 isoform is expressed in human respiratory epithelia and is upregulated in response to interferons and RNA respiratory virus infection

Angiotensin-converting enzyme 2 (ACE2) is the main entry point in airway epithelial cells for SARS-CoV-2. ACE2 binding to the SARS-CoV-2 protein spike triggers viral fusion with the cell plasma membrane, resulting in viral RNA genome delivery into the host. Despite ACE2's critical role in SARS-CoV-2 infection, full understanding of ACE2 expression, including in response to viral infection, remains unclear. ACE2 was thought to encode five transcripts and one protein of 805 amino acids. In the present study, we identify a novel short isoform of ACE2 expressed in the airway epithelium, the main site of SARS-CoV-2 infection. Short ACE2 is substantially upregulated in response to interferon stimulation and rhinovirus infection, but not SARS-CoV-2 infection. This short isoform lacks SARS-CoV-2 spike high-affinity binding sites and, altogether, our data are consistent with a model where short ACE2 is unlikely to directly contribute to host susceptibility to SARS-CoV-2 infection.

COVID-19 Antiviral and Treatment Candidates: Current Status

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 has severely impacted global health and economy. There is currently no effective approved treatment for COVID-19; although vaccines have been granted emergency use authorization in several countries, they are currently only administered to high-risk individuals, thereby leaving a gap in virus control measures. The scientific and clinical communities and drug manufacturers have collaborated to speed up the discovery of potential therapies for COVID-19 by taking advantage of currently approved drugs as well as investigatory agents in clinical trials. In this review, we stratified some of these candidates based on their potential targets in the progression of COVID-19 and discuss some of the results of ongoing clinical evaluations.

Leveraging the antiviral type I interferon system as a first line of defense against SARS-CoV-2 pathogenicity

The emergence and spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in significant global morbidity, mortality, and societal disruption. A better understanding of virus-host interactions may potentiate therapeutic insights toward limiting this infection. Here we investigated the dynamics of the systemic response to SARS-CoV-2 in hamsters by histological analysis and transcriptional profiling. Infection resulted in consistently high levels of virus in the upper and lower respiratory tracts and sporadic occurrence in other distal tissues. A longitudinal cohort revealed a wave of inflammation, including a type I interferon (IFN-I) response, that was evident in all tissues regardless of viral presence but was insufficient to prevent disease progression. Bolstering the antiviral response with intranasal administration of recombinant IFN-I reduced viral disease, prevented transmission, and lowered inflammation in vivo. This study defines the systemic host response to SARS-CoV-2 infection and supports use of intranasal IFN-I as an effective means of early treatment.

Mucosal immune responses in COVID19 - a living review

COVID-19 was initially characterized as a disease primarily of the lungs, but it is becoming increasingly clear that the SARS-CoV2 virus is able to infect many organs and cause a broad pathological response. The primary infection site is likely to be a mucosal surface, mainly the lungs or the intestine, where epithelial cells can be infected with virus. Although it is clear that virus within the lungs can cause severe pathology, driven by an exaggerated immune response, infection within the intestine generally seems to cause minor or no symptoms. In this review, we compare the disease processes between the lungs and gastrointestinal tract, and what might drive these different responses. As the microbiome is a key part of mucosal barrier sites, we also consider the effect that microbial species may play on infection and the subsequent immune responses. Because of difficulties obtaining tissue samples, there are currently few studies focused on the local mucosal response rather than the systemic response, but understanding the local immune response will become increasingly important for understanding the mechanisms of disease in order to develop better treatments.

SP-A and SP-D: Dual Functioning Immune Molecules With Antiviral and Immunomodulatory Properties

Surfactant proteins A (SP-A) and D (SP-D) are soluble innate immune molecules which maintain lung homeostasis through their dual roles as anti-infectious and immunomodulatory agents. SP-A and SP-D bind numerous viruses including influenza A virus, respiratory syncytial virus (RSV) and human immunodeficiency virus (HIV), enhancing their clearance from mucosal points of entry and modulating the inflammatory response. They also have diverse roles in mediating innate and adaptive cell functions and in clearing apoptotic cells, allergens and other noxious particles. Here, we review how the properties of these first line defense molecules modulate inflammatory responses, as well as host-mediated immunopathology in response to viral infections. Since SP-A and SP-D are known to offer protection from viral and other infections, if their levels are decreased in some disease states as they are in severe asthma and chronic obstructive pulmonary disease (COPD), this may confer an increased risk of viral infection and exacerbations of disease. Recombinant molecules of SP-A and SP-D could be useful in both blocking respiratory viral infection while also modulating the immune system to prevent excessive inflammatory responses seen in, for example, RSV or coronavirus disease 2019 (COVID-19). Recombinant SP-A and SP-D could have therapeutic potential in neutralizing both current and future strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus as well as modulating the inflammation-mediated pathology associated with COVID-19. A recombinant fragment of human (rfh)SP-D has recently been shown to neutralize SARS-CoV-2. Further work investigating the potential therapeutic role of SP-A and SP-D in COVID-19 and other infectious and inflammatory diseases is indicated.

Effects of Interferon Beta in COVID-19 adult patients: Systematic Review

Background

The high rate of transmission and infection of coronavirus disease 2019 (COVID-19) is a public health emergency of major epidemiological concern. No definitive treatments have been established, and vaccinations have only recently begun. We aim to review the efficacy and safety of Interferon Beta (IFN-β) in patients who have a confirmed COVID-19 diagnosis.

Materials and Methods

A search from PubMed, Science Direct, Cochrane, and Clinicaltrials.gov databases were conducted from December 2019 to December 2020 to review the efficacy and safety of IFN-β in adult patients with COVID-19 confirmed. We included randomized controlled trials, case reports, and experimental studies. Correspondences, letters, editorials, reviews, commentaries, case control, cross-sectional, and cohort studies that did not include any new clinical data were excluded.

Results

Of the 66 searched studies, 8 were included in our review. These studies demonstrated that although IFN-β did not reduce the time to clinical response, there was an increase in discharge rate at day 14 and a decrease in mortality at day 28. The time to negative reverse transcription polymerase chain reaction (RT-PCR) was shown to be significantly shortened in patients receiving IFN-β, along with a lower nasopharyngeal viral load. Further, patients receiving IFN-β had a less significant rise in IL-6. IFN-β was shown to decrease intensive care unit (ICU) admission rate, the requirement of invasive ventilation in severe cases, and improve the survival rate compared to control groups. There were no severe adverse events reported. Our review found that patients who received early treatment with IFN-β experienced significantly reduced length of hospitalization, mortality, ICU admission, and mechanical ventilation. A greater chance of clinical improvement and improved imaging studies was noted in patients who received IFN-β. There were no reported deaths associated with the addition of IFN-β. Further randomized trials involving more significant sample sizes are needed to better understand the effect of IFN-β on survival in COVID-19.

Conclusion

This review identified encouraging data and outcomes of incorporating IFN-β to treat COVID-19 patients. IFN-β has been shown to decrease hospital stay's overall length and decrease the severity of respiratory symptoms when added to the standard of care. Also, in some studies, it has been demonstrated to reduce the length of ICU stay, enhance survival rate, and decrease the need for invasive mechanical ventilation. There were minor side effects reported (neuropsychiatric symptoms and hypersensitivity reaction). However, randomized clinical trials with a large sample size are needed to assess IFN-β's benefit precisely.