DEVELOPMENT OF A TEST SYSTEM AND A METHOD FOR DETECTING RIBONUCLEIC ACID OF SEVERE ACUTE RESPIRATORY SYNDROME CORONAVIRUS 2 USING REAL-TIME POLYMERASE CHAIN REACTION

Given the rapid spread of coronavirus disease 2019 (COVID-19) globally, test systems are needed for its diagnosis, timely treatment, and introduction of quarantine measures. In the shortest possible time, a diagnostic system based on real-time reverse-transcription polymerase chain reaction to detect the ribonucleic acid of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in nasopharyngeal and oropharyngeal smears was developed and registered. The method determines the nucleocapsid and small-membrane protein genes and the human PGK1 gene, acting as internal control reactions. The nucleotide sequences of SARS-CoV-2 were analyzed, and primers were selected. The conditions for carrying out real-time reverse-transcription polymerase chain reaction and the composition of a set of reagents were set. The diagnostic sensitivity and specificity of the kit were tested on biological samples, with the addition of inactivated SARSCoV-2. The high analytical characteristics of the developed set of reagents were demonstrated, with a sensitivity of at least 103 GE/mL and a specificity of 100%, and no false-positive or false-negative results were recorded. The high specificity of the test system was shown on a representative sample of genetic materials of respiratory viral pathogens. Clinical and laboratory tests of the diagnostic "SARS-CoV-2 test” were conducted in the N.F. Gamalei National Research Center for Epidemiology and Microbiology. A set of reagents for the detection of ribonucleic acid of SARS-CoV-2 through on real-time reverse-transcription polymerase chain reaction for in vitro diagnostics "SARS-CoV-2 test” was registered in the Russian Federation as a medical device (Registration certificate no. RZN 2020/10632, dated 06/03/2020). The article can be used under the CC BY-NC-ND 4.0 license © Authors, 2022.

The Air and Viruses We Breathe: Assessing the Effect the PM2.5 Air Pollutant Has on the Burden of COVID-19

Evidence suggests an association between air pollutant exposure and worse outcomes for respiratory viral diseases, like COVID-19. However, does breathing polluted air over many years affect the susceptibility to SARS-CoV-2 infection or severity of COVID-19 disease, and how intense are these effects? As climate change intensifies, air pollutant levels may rise, which might further affect the burden of respiratory viral diseases. We assessed the effect of increasing exposure to PM2.5 (particulate matter = 2.5 microns in diameter) on SARS-CoV-2 susceptibility or COVID-19 severity and projected the impact on infections and hospitalisations over two years. Simulations in a hypothetical, representative population show that if exposure affects severity, then hospital admissions are projected to increase by 5-10% for a one-unit exposure increase. However, if exposure affects susceptibility, then infections would increase with the potential for onward transmission and hospital admissions could increase by over 60%. Implications of this study highlight the importance of considering this potential additional health and health system burden as part of strategic planning to mitigate and respond to changing air pollution levels. It is also important to better understand at which point PM2.5 exposure affects SARS-CoV-2 infection through to COVID-19 disease progression, to enable improved protection and better support of those most vulnerable.

[Clinic and functional features of chronic obstructive pulmonary disease after virus-induced acute exacerbations.]

AIM: To establish symptoms, lung function and to evaluate subsequent exacerbations of chronic obstructive pulmonary disease (COPD) during a year after virus-induced COPD exacerbations. MATERIALS AND METHODS: Patients hospitalized with viral (n=60), bacterial (n=60) and viral-bacterial (n=60) COPD exacerbations were enrolled to single-center prospective observational study. COPD was diagnosed according spirography criteria. Viral infection was established in bronchoalveolar lavage fluid or sputum by real-time reverse transcription-polymerase chain reaction for RNA of influenza A and B virus, rhinovirus, respiratory syncytial virus and SARS-CoV-2. Symptoms, lung function, COPD exacerbations were assessed. Patients were investigated at the hospitalization onset and then 4 and 52 weeks following the discharge from the hospital. RESULTS: After 52 weeks in viral and viral-bacterial COPD exacerbations groups the rate of forced expiratory volume in one second (FEV1) decline were maximal - 71 (68; 73) ml/year and 69 (67; 72) ml/year versus 59 (55; 62) ml/year after bacterial exacerbations. Low levels of diffusion lung capacity for carbon monoxide (DLco/Va) - 52.5% (45.1%; 55.8%), 50.2% (44.9%; 56.0%) and 75.3% (72.2%; 80.1%) respectively, of 6-minute walk distance; p<0.001 in relation to bacterial exacerbations. In Cox proportional hazards regression analyses viral and viral-bacterial exacerbations were associated with increased risk of subsequent COPD exacerbations by 2.4 times independent of exacerbations rate before index event and FEV1. In linear regression models the relationships between airflow limitation and respiratory syncytial virus, rhinovirus and influenza virus infection, between low DLco/Va and rhinovirus, influenza virus and SARS-CoV-2 infection. CONCLUSION: COPD after virus-induced exacerbations were characterized by progression of airflow limitation, low DLco/Va, low 6-minute walking test distance, subsequent COPD exacerbations risk.

Respiratory Viral Infections in Recipients of Cellular Therapies: A Review of Incidence, Outcomes, Treatment, and Prevention.

Respiratory viral infections (RVIs) are of major clinical importance in immunocompromised patients and represent a substantial cause of morbidity and mortality in patients with hematologic malignancies and those who have undergone hematopoietic cell transplantation. Similarly, patients receiving immunotherapy with CD19-targeted chimeric antigen receptor-modified T cells, natural killer cells, and genetically modified T-cell receptors are susceptible to RVIs and progression to lower respiratory tract infections. In adoptive cellular therapy recipients, this enhanced susceptibility to RVIs results from previous chemotherapy regimens such as lymphocyte-depleting chemotherapy conditioning regimens, underlying B-cell malignancies, immune-related toxicities, and secondary prolonged, profound hypogammaglobulinemia. The aggregated risk factors for RVIs have both immediate and long-term consequences. This review summarizes the current literature on the pathogenesis, epidemiology, and clinical aspects of RVIs that are unique to recipients of adoptive cellular therapy, the preventive and therapeutic options for common RVIs, and appropriate infection control and preventive strategies.

A novel anterior nasal swab to detect respiratory viruses: a prospective study of diagnostic accuracy.

Detection of respiratory viruses requires testing of the upper respiratory tract to obtain specimens for analysis. However, nasal and throat swabs can cause discomfort and procedural anxiety in children. Respiratory sampling methods which are accurate and less invasive are needed. We aim to determine the positive and negative percentage agreement of a novel anterior nasal swab (ANS) compared with the combined throat and anterior nasal swab (CTN), the reference standard, for detection of respiratory viruses. Children 5 - 18 years of age presenting to a tertiary paediatric hospital with respiratory symptoms were tested with both swabs in randomised order. Respiratory samples were tested on a multiplex RT-PCR panel. Viral detections, RT-PCR cycle-threshold values and child/parent/clinician experience of the swab were recorded. There were 157 viral detections from 249 participant CTN swabs. In comparison with the CTN, the overall positive and negative percentage agreement of ANS for detection of respiratory viruses was 96.2% (95% CI, 91.8-98.3%) and 99.8% (95% CI, 99.6-99.9%), respectively. The ANS was "extremely comfortable", or only a "little uncomfortable" for 90% of children compared with 48% for CTN. 202 children (84%) rated the ANS as the preferred swab, and 208 (87%) indicated they would prefer ANS for future testing. The ANS required additional laboratory handling processes compared to the CTN. The ANS has high positive percentage agreement and is comparable to the current standard of care. The high acceptability from the less invasive ANS provides a more comfortable method for respiratory virus testing in children.Trial registrationClinicalTrials.gov ID NCT05043623.

Role of antiviral therapy in respiratory infections in children: Analysis of clinical and laboratory observations.

Objective. To evaluate the efficacy of therapy for acute respiratory viral infections (ARVIs) in children with antiviral medications: inosine pranobex (Groprinosin, Gedeon Richter) and Kagocel (Kagocel, Niarmedic Pharma LLC) in comparison with symptomatic treatment without etiotropic agents based on clinical and laboratory parameters. Patients and methods. The clinical and laboratory observation was conducted in an outpatient setting in the pre-COVID-19 period between 2018 and 2020. Acute respiratory infections were diagnosed using licensed testing systems by multiplex polymerase chain reaction (PCR) with detection of nucleic acid viral genomes: influenza, rhinovirus, respiratory syncytial virus, metapneumovirus, parainfluenza, seasonal coronaviruses, adenoviruses, and bocavirus). A total of 151 children aged 3 to 15 years were examined and monitored in dynamics, with 78.7% of positive and 21.3% of negative results detected by PCR in the nasopharyngeal and oropharyngeal swabs. The patients were randomized into three groups depending on the antiviral medication prescribed: group 1 (53 children) received Groprinosin;group 2 (52 children) received Kagocel;group 3 (control, 46 children) received only symptomatic therapy without antiviral agents. Results. The study demonstrated a significant positive effect in patients in group 1 treated with Groprinosin (n = 53). At the end of therapy for both mono- and mixed infections, there were 95.8% of negative results (according to PCR diagnosis, that is, the absence of viral genome). In children in group 2 (n = 52) treated with Kagocel, the absence of viral nucleic acids (NAs) was observed less frequently (in 77.3% of cases). In children in group 3 (n = 46) who did not receive etiotropic antiviral therapy, there were only 40.3% of negative results after the end of treatment, and viral NAs were detected in 59.7% of patients. In this case, a 5-day course of Groprinosin was prescribed, after which the PCR results became negative in all patients. Therefore, children with recurrent respiratory infections, mixed infections, and herpesvirus infections require longer therapy. Additionally, a high frequency of ARVI complications was noted in group 3 (5 (10.9%) patients, where otitis was observed in 1 case, sinusitis - in 2 cases, bronchitis - in 2 cases), whereas 1 (1.8%) patient taking Groprinosin had otitis, and 1 (1.9%) patient taking Kagocel had pneumonia. Conclusion. This study was the first to investigate antibody titers to respiratory viruses in dynamics at 3, 6 and 12 months after the onset of ARVI. It showed that the development of antibodies to respiratory viruses is very unstable and does not occur in all patients. Antibodies almost disappeared by the third month after ARVI and were no longer detectable by the sixth month. After 12 months, patients suffered a new ARVI and developed the corresponding antibodies. This information will be especially relevant in conditions of the rise in the incidence of ARVIs, as well as the COVID-19 pandemic observed in recent years.Copyright © 2022, Voprosy Prakticheskoi Pediatrii. All rights reserved.

Vitamin D in respiratory viral infections: a key immune modulator?

Respiratory viral infections are common respiratory diseases. Influenza viruses, RSV and SARS-COV2 have the potential to cause severe respiratory infections. Numerous studies have shown that unregulated immune response to these viruses can cause excessive inflammation and tissue damage. Therefore, regulating the antiviral immune response in the respiratory tract is of importance. In this regard, recent years studies have emphasized the importance of vitamin D in respiratory viral infections. Although, the most well-known role of vitamin D is to regulate the metabolism of phosphorus and calcium, it has been shown that this vitamin has other important functions. One of these functions is immune regulation. Vitamin D can regulate the antiviral immune response in the respiratory tract in order to provide an effective defense against respiratory viral infections and prevention from excessive inflammatory response and tissue damage. In addition, this vitamin has preventive effects against respiratory viral infections. Some studies during the COVID-19 pandemic have shown that vitamin D deficiency may be associated with a higher risk of mortality and sever disease in patients with COVID-19. Since, more attention has recently been focused on vitamin D. In this article, after a brief overview of the antiviral immune response in the respiratory system, we will review the role of vitamin D in regulating the antiviral immune response comprehensively. Then we will discuss the importance of this vitamin in influenza, RSV, and COVID-19.

An alternative mechanism for skeletal muscle dysfunction in long-term post-viral lung disease.

Chronic lung disease is often accompanied by disabling extrapulmonary symptoms, notably skeletal muscle dysfunction and atrophy. Moreover, the severity of respiratory symptoms correlates with decreased muscle mass and in turn lowered physical activity and survival rates. Previous models of muscle atrophy in chronic lung disease often modeled chronic obstructive pulmonary disease (COPD) and relied on cigarette smoke exposure and LPS stimulation, but these conditions independently affect skeletal muscle even without accompanying lung disease. Moreover, there is an emerging and pressing need to understand the extrapulmonary manifestations of long-term post-viral lung disease (PVLD) as found in COVID-19. Here, we examine the development of skeletal muscle dysfunction in the setting of chronic pulmonary disease caused by infection due to the natural pathogen Sendai virus using a mouse model of PVLD. We identify a significant decrease in myofiber size when PVLD is maximal at 49 days after infection. We find no change in the relative types of myofibers, but the greatest decrease in fiber size is localized to fast-twitch-type IIB myofibers based on myosin heavy chain immunostaining. Remarkably, all biomarkers of myocyte protein synthesis and degradation (total RNA, ribosomal abundance, and ubiquitin-proteasome expression) were stable throughout the acute infectious illness and chronic post-viral disease process. Together, the results demonstrate a distinct pattern of skeletal muscle dysfunction in a mouse model of long-term PVLD. The findings thereby provide new insights into prolonged limitations in exercise capacity in patients with chronic lung disease after viral infections and perhaps other types of lung injury.NEW & NOTEWORTHY Our study used a mouse model of post-viral lung disease to study the impact of chronic lung disease on skeletal muscle. The model reveals a decrease in myofiber size that is selective for specific types of myofibers and an alternative mechanism for muscle atrophy that might be independent of the usual markers of protein synthesis and degradation. The findings provide a basis for new therapeutic strategies to correct skeletal muscle dysfunction in chronic respiratory disease.

Rhino- and Rs-Viruses in the Covid-19 Pandemic

Acute respiratory viral infections are distributed across the globe and are the most numerous human diseases caused by several hundreds of diverse viruses. Human rhinovirus is one of the most common respiratory pathogens worldwide, causing more than half of all acute respiratory viral infection cases. Seasonal human coronaviruses account for 10-15% of common cold cases;respiratory syncytial (RS) virus is the most common cause of respiratory hospitalization in infants;influenza viruses, adenoviruses, human parainfluenza virus, metapneumoviruses, and some other pathogens are also widespread. It is believed that viral common colds are mostly self-limited, causing mild infections that usually resolve within 8-10 days. However, the role of common seasonal respiratory viruses in total respiratory morbidity should not be underestimated. It turned out that during extraordinary conditions of pandemics, they behave differently. This was clearly demonstrated in the last 2009 influenza pandemic. Whereas some viruses lost relevance under the burden of a new aggressive pandemic strain, others, e.g., rhinovirus, continued to fight for existence and not only circulated along with the pandemic pathogen, but delayed its spread in some cases. For instance, the data from some European countries pointed out that the circulation of the H1N1pdm09 influenza A pandemic virus was interrupted by the annual rhinovirus outbreak. Ten years after the H1N1pdm09 influenza pandemic, a new virus outbreak emerged - the COVID-19 pandemic has begun. This pandemic, caused by the SARS-CoV-2 virus, has disrupted well-established pathogenetic and epidemiological relationships. The level of circulation of many respiratory pathogens has changed dramatically. For instance, global influenza activity has been at a much lower level than expected for the second year from now. In many regions of the world, the flu season has not been started yet. But what is interesting is that rhinoviruses together with RS-virus again showed their unique ability to compete with highly pathogenic and aggressive pathogens. Along with profoundly reduced circulation of many other seasonal respiratory viruses, rhinovirus, and RS-virus are the most frequently detected viruses. In this review, we have brought together the main biological characteristics of such genetically distinct viruses such as rhinovirus, influenza A virus, RS-virus, and SARS-CoV-2. We focused on their main similarities and discrepancies in the attempt to understand why they behave so differently in extreme pandemic conditions as well as what allows rhinoviruses and RS-viruses to coexist with SARS-CoV-2, which in turn almost fully replaced the influenza virus.

EPIDEMIOLOGY AND COURSE OF INFECTIOUS DISEASES DURING THE COVID-19 PANDEMIC. REPORT 2. INTERFERENCE ENGAGED BETWEEN SARS-CoV-2 AND ACUTE RESPIRATORY VIRAL INFECTIONS

Currently, the disease caused by the new coronavirus (COVID-19) and the possibility of co-infection with SARS-CoV-2 and other pathogens in the current epidemic situation continues to be of particular interest. The review, based on the analysis of literature and own materials, outlines the features of the relationship between SARS-CoV-2 and pathogens of acute respiratory viral infections (ARVI). Particular attention is paid to the combined course of COVID-19 and influenza, a comparative characteristic of the severity of the clinical picture. An assessment of the epidemic situation against the backdrop of the COVID-19 pandemic in foreign countries and the Russian Federation (RF) revealed the pres-ence of the phenomenon of SARS-CoV-2 interference with other viral respiratory agents, based on the facts of a sharp suppression of the circulation of influenza viruses, respiratory syncytial virus (RSV) and other ARVI pathogens during the period of active spread of pandemic coronavirus. The main epidemiological indicators of the course of coronavirus infection were compared and the contribution of various pathogens to the etiology of acute respiratory viral infections during the development of the second wave of COVID-19 in the RF was assessed. It was noted that the decrease in the number of new cases by 11.4 and deaths by 2.1 times due to COVID-19 at 6 and 13 weeks in 2022 occurred with unchanged laboratory detection of the influenza virus (0.8%) and an increase in the frequency detection of pathogens of other SARS. The results of observations showed that against the background of a decrease in the incidence of COVID-19, there was no increase in the proportion of diagnosed cases of infections caused by other pathogens, especially influenza. The re-sults obtained confirm the need to ensure effective epidemiological surveillance and additional application of pathogen identification methods for monitoring various ARVI, which can significantly affect the approach to differential diagnosis, patient management tactics and the decision on appropriate preventive measures.

Neurological diseases caused by coronavirus infection of the respiratory airways

Infections of the central nervous system (CNS) infections are critical problems for public health. They are caused by several different organisms, including the respiratory coronaviruses (CoVs). CoVs usually infect the upper respiratory tract causing the common cold. However, in infants, and in elderly and immunocompromised persons, they can also affect the lower respiratory tract causing pneumonia and various syndromes of respiratory distress. CoVs also have neuroinvasive capabilities because they can spread from the respiratory tract to the CNS. Once infection begins in the CNS cells, it can cause various CNS problems such as status epilepticus, encephalitis, and long‐term neurological disease. This neuroinvasive properties of CoVs may damage the CNS as a result of misdirected host immune response, which could be associated with autoimmunity in susceptible individuals (virus‐induced neuro‐immunopathology) or associated with viral replication directly causing damage to the CNS cells (virus‐induced neuropathology). In December 2019, a new disease named COVID‐19 emerged which is caused by CoVs. The significant clinical symptoms of COVID‐19 are related to the respiratory system, but they can also affect the CNS, causing acute cerebrovascular and intracranial infections. We describe the possible invasion routes of coronavirus in this review article, and look for the most recent findings associated with the neurological complications in the recently published literature.

Role of antiviral therapy in respiratory infections in children: Analysis of clinical and laboratory observations.

Objective. To evaluate the efficacy of therapy for acute respiratory viral infections (ARVIs) in children with antiviral medications: inosine pranobex (Groprinosin, Gedeon Richter) and Kagocel (Kagocel, Niarmedic Pharma LLC) in comparison with symptomatic treatment without etiotropic agents based on clinical and laboratory parameters. Patients and methods. The clinical and laboratory observation was conducted in an outpatient setting in the pre-COVID-19 period between 2018 and 2020. Acute respiratory infections were diagnosed using licensed testing systems by multiplex polymerase chain reaction (PCR) with detection of nucleic acid viral genomes: influenza, rhinovirus, respiratory syncytial virus, metapneumovirus, parainfluenza, seasonal coronaviruses, adenoviruses, and bocavirus). A total of 151 children aged 3 to 15 years were examined and monitored in dynamics, with 78.7% of positive and 21.3% of negative results detected by PCR in the nasopharyngeal and oropharyngeal swabs. The patients were randomized into three groups depending on the antiviral medication prescribed: group 1 (53 children) received Groprinosin;group 2 (52 children) received Kagocel;group 3 (control, 46 children) received only symptomatic therapy without antiviral agents. Results. The study demonstrated a significant positive effect in patients in group 1 treated with Groprinosin (n = 53). At the end of therapy for both mono- and mixed infections, there were 95.8% of negative results (according to PCR diagnosis, that is, the absence of viral genome). In children in group 2 (n = 52) treated with Kagocel, the absence of viral nucleic acids (NAs) was observed less frequently (in 77.3% of cases). In children in group 3 (n = 46) who did not receive etiotropic antiviral therapy, there were only 40.3% of negative results after the end of treatment, and viral NAs were detected in 59.7% of patients. In this case, a 5-day course of Groprinosin was prescribed, after which the PCR results became negative in all patients. Therefore, children with recurrent respiratory infections, mixed infections, and herpesvirus infections require longer therapy. Additionally, a high frequency of ARVI complications was noted in group 3 (5 (10.9%) patients, where otitis was observed in 1 case, sinusitis - in 2 cases, bronchitis - in 2 cases), whereas 1 (1.8%) patient taking Groprinosin had otitis, and 1 (1.9%) patient taking Kagocel had pneumonia. Conclusion. This study was the first to investigate antibody titers to respiratory viruses in dynamics at 3, 6 and 12 months after the onset of ARVI. It showed that the development of antibodies to respiratory viruses is very unstable and does not occur in all patients. Antibodies almost disappeared by the third month after ARVI and were no longer detectable by the sixth month. After 12 months, patients suffered a new ARVI and developed the corresponding antibodies. This information will be especially relevant in conditions of the rise in the incidence of ARVIs, as well as the COVID-19 pandemic observed in recent years.Copyright © 2022, Voprosy Prakticheskoi Pediatrii. All rights reserved.

Differences in the structure of infectious morbidity of the population during the first and second half of 2020 in st. petersburg

This chapter focuses on the comparative statistical analysis of the incidence of acute respiratory viral infections (ARVI), new coronavirus infection Covid-19 and community-acquired pneumonia in one of the administrative districts of St. Petersburg. It was found that the total number of people with ARVI, new coronavirus infection Covid-19 and community acquired pneumonia observed in pediatric and adult clinics had two "waves". In the structure of the incidence of Covid-19 in the first "wave", adult patients prevailed. During the second "wave" of the rise in the incidence of Covid-19, the proportion of children doubled to 12.9%. The increased infectious morbidity required the involvement of additional medical personnel, transport, as well as the introduction of new organizational technologies for providing medical care to the population. The data of regular statistical observation became the basis for making operational management decisions for the organization of medical care for the population in the context of an epidemic rise in morbidity. © ISTE Ltd 2022.

SERS/photothermal-based dual-modal lateral flow immunoassays for sensitive and simultaneous antigen detection of respiratory viral infections

Lateral flow immunoassay (LFIA) is one of the most common analytical platforms for point-of-care testing (POCT), which is capable of large-scale primary screening and home self-testing of infectious diseases. However, the sensitivity of conventional AuNPs-based LFIA is relatively low and more prone to false negatives. Herein, we report a novel LFIA based on gold-core-silver-shell bimetallic nanoparticles (Au4-ATP@Ag NPs) emitting Surface-enhanced Raman scatting (SERS) and Photothermal (PT) effect, named SERS/PT-based dual-modal LFIA (SERS/PT-dmLFIA), for the antigen detection of infectious diseases pathogens, which displayed an excellent performance. For influenza A virus (IAV), influenza B virus (IBV), and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) N protein detection, the limit of detections (LoD) with Raman as signal were 31.25, 93.75, and 31.25 pg mL-1 respectively, and the LoDs with temperature difference (∆T) as signal were as low as 15.63, 187.5, and 15.63 pg mL-1 respectively, which were over 4-fold more sensitive than visual-based LFIA. The proposed SERS/PT-dmLFIA was used for detecting virus antigen in pharyngeal swabs and showed ideal coincidence rate of over 95% compared to the commercialized assays. In addition, we explored the development of multiplex SERS/PT-dmLFIA that can detect IAV, IBV, and SARS-CoV-2 antigens simultaneously without cross reactivity. Overall, the SERS/PT-dmLFIA for antigen detection not only exhibits high sensitivity, accuracy and specificity, but also have characteristics of rapidity and simplicity, which holds high potential for rapid diagnosis of infectious diseases in laboratory testing, mass screening, and home self-testing. © 2023 Elsevier B.V.

Extraction of niclosamide from commercial approved tablets into aqueous buffered solution creates potentially approvable oral and nasal sprays against COVID-19 and other respiratory infections.

Motivation: The low solubility, weak acid drug, niclosamide is a host cell modulator with broad-spectrum anti-viral cell-activity against many viruses, including stopping the SARS-CoV-2 virus from infecting cells in cell culture. As a result, a simple universal nasal spray preventative was proposed and investigated in earlier work regarding the dissolution of niclosamide into simple buffers. However, starting with pharmaceutical grade, niclosamide represents a new 505(b)(2) application. The motivation for this second paper in the series was therefore to explore if and to what extent niclosamide could be extracted from commercially available and regulatory-approved niclosamide oral tablets that could serve as a preventative nasal spray and an early treatment oral/throat spray, with possibly more expeditious testing and regulatory approval. Experimental: Measurements of supernatant niclosamide concentrations were made by calibrated UV-Vis for the dissolution of niclosamide from commercially available Yomesan crushed into a powder for dissolution into Tris Buffer (TB) solutions. Parameters tested were as follows: time (0-2 days), concentration (300 µM to -1 mM), pH (7.41 to 9.35), and anhydrous/hydrated state. Optical microscopy was used to view the morphologies of the initial crushed powder, and the dissolving and equilibrating undissolved excess particles to detect morphologic changes that might occur. Results: Concentration dependence: Niclosamide was readily extracted from powdered Yomesan at pH 9.34 TB at starting Yomesan niclosamide equivalents concentrations of 300 µM, 600 µM, and 1 mM. Peak dissolved niclosamide supernatant concentrations of 264 µM, 216 µM, and 172 µM were achieved in 1 h, 1 h, and 3 h respectively. These peaks though were followed by a reduction in supernatant concentration to an average of 112.3 µM ± 28.4 µM after overnight stir on day 2. pH dependence: For nominal pHs of 7.41, 8.35, 8.85, and 9.35, peak niclosamide concentrations were 4 µM, 22.4 µM, 96.2 µM, and 215.8 µM, respectively. Similarly, the day 2 values all reduced to 3 µM, 12.9 µM, 35.1 µM, and 112.3 µM. A heat-treatment to 200 °C dehydrated the niclosamide and showed a high 3 h concentration (262 µM) and the least day-2 reduction (to 229 µM). This indicated that the presence, or formation during exposure to buffer, of lower solubility polymorphs was responsible for the reductions in total solubilities. These morphologic changes were confirmed by optical microscopy that showed initially featureless particulate-aggregates of niclosamide could grow multiple needle-shaped crystals and form needle masses, especially in the presence of Tris-buffered sodium chloride, where new red needles were rapidly made. Scale up: A scaled-up 1 L solution of niclosamide was made achieving 165 µM supernatant niclosamide in 3 h by dissolution of just one fifth (100 mg niclosamide) of a Yomesan tablet. Conclusion: These comprehensive results provide a guide as to how to utilize commercially available and approved tablets of niclosamide to generate aqueous niclosamide solutions from a simple dissolution protocol. As shown here, just one 4-tablet pack of Yomesan could readily make 165 L of a 20 µM niclosamide solution giving 16,500 10 mL bottles. One million bottles, from just 60 packs of Yomesan, would provide 100 million single spray doses for distribution to mitigate a host of respiratory infections as a universal preventative-nasal and early treatment oral/throat sprays throughout the world. Graphical Abstract: pH dependence of niclosamide extraction from crushed Yomesan tablet material into Tris buffer (yellow-green in vial) and Tris-buffered saline solution (orange-red in vial). Initial anhydrous dissolution concentration is reduced by overnight stirring to likely monohydrate niclosamide; and is even lower if in TBSS forming new niclosamide sodium needle crystals grown from the original particles. Supplementary Information: The online version contains supplementary material available at 10.1186/s41120-023-00072-x.

Recent Advances in Inhaled Nanoformulations of Vaccines and Therapeutics Targeting Respiratory Viral Infections.

With the rapid outbreak of respiratory viral infections, various biological (e.g. vaccines, peptides, recombinant proteins, antibodies and genes) and antiviral agents (e.g. ribavirin, palivizumab and valaciclovir) have been successfully developed for the treatment of respiratory virus infections such as influenza, respiratory syncytial virus and SARS-CoV-2 infections. These therapeutics are conventionally delivered via oral, intramuscular or injection route and are associated with several adverse events due to systemic toxicity. The inherent in vivo instability of biological therapeutics may hinder them from being administered without proper formulations. Therefore, we have witnessed a boom in nanotechnology coupled with a needle-free administration approach such as the inhalation route for the delivery of complex therapeutics to treat respiratory infections. This review discussed the recent advances in the inhalation strategies of nanoformulations that target virus respiratory infections.

Neutralisation of SARS-CoV-2 by monoclonal antibody through dual targeting powder formulation.

Neutralising monoclonal antibody (mAb) is an important weapon in our arsenal for combating respiratory viral infections. However, the effectiveness of neutralising mAb has been impeded by the rapid emergence of mutant variants. Early administration of broad-spectrum mAb with improved delivery efficiency can potentially enhance efficacy and patient outcomes. WKS13 is a humanised mAb which was previously demonstrated to exhibit broad-spectrum activity against SARS-CoV-2 variants. In this study, a dual targeting formulation strategy was designed to deliver WKS13 to both the nasal cavity and lower airways, the two critical sites of infection caused by SARS-CoV-2. Dry powders of WKS13 were first prepared by spray drying, with cyclodextrin used as stabiliser excipient. Two-fluid nozzle (TFN) was used to produce particles below 5 µm for lung deposition (C-TFN formulation) and ultrasonic nozzle (USN) was used to produce particles above 10 µm for nasal deposition (C-USN formulation). Gel electrophoresis and size exclusion chromatography studies showed that the structural integrity of mAb was successfully preserved with no sign of aggregation after spray drying. To achieve dual targeting property, C-TFN and C-USN were mixed at various ratios. The aerosolisation property of the mixed formulations dispersed from a nasal powder device was examined using a Next Generation Impactor (NGI) coupled with a glass expansion chamber. When the ratio of C-TFN in the mixed formulation increased, the fraction of particles deposited in the lung increased proportionally while the fraction of particles deposited in the nasal cavity decreased correspondingly. A customisable aerosol deposition profile could therefore be achieved by manipulating the mixing ratio between C-TFN and C-USN. Dual administration of C-TFN and C-USN powders to the lung and nasal cavity of hamsters, respectively, was effective in offering prophylactic protection against SARS-CoV-2 Delta variant. Viral loads in both the lung tissues and nasal wash were significantly reduced, and the efficacy was comparable to systemic administration of unformulated WKS13. Overall, dual targeting powder formulation of neutralising mAb is a promising approach for prophylaxis of respiratory viral infections. The ease and non-invasive administration of dual targeting nasal powder may facilitate the widespread distribution of neutralising mAb during the early stage of unpredictable outbreaks.

Clinical relevance and therapeutic potential of IL-38 in immune and non-immune-related disorders

Interleukin-38 (IL-38) is the most recent member of the IL-1 family that acts as a natural inflammatory inhibitor by binding to cognate receptors, particularly the IL-36 receptor. In vitro, animal and human studies on autoimmune, metabolic, cardiovascular and allergic diseases, as well sepsis and respiratory viral infections, have shown that IL-38 exerts an anti-inflammatory activity by modulating the generation and function of inflammatory cytokines (e.g. IL-6, IL-8, IL-17 and IL-36) and regulating dendritic cells, M2 macrophages and regulatory T cells (Tregs). Accordingly, IL-38 may possess therapeutic potential for these types of diseases. IL-38 down-regulates CCR3+ eosinophil cells, CRTH2+ Th2 cells, Th17 cells, and innate lymphoid type 2 cells (ILC2), but up-regulates Tregs, and this has influenced the design of immunotherapeutic strategies based on regulatory cells/cytokines for allergic asthma in future studies. In auto-inflammatory diseases, IL-38 alleviates skin inflammation by regulating γδ T cells and limiting the production of IL-17. Due to its ability to suppress IL-1ß, IL-6 and IL-36, this cytokine could reduce COVID-19 severity, and might be employed as a therapeutic tool. IL-38 may also influence host immunity and/or the components of the cancer microenvironment, and has been shown to improve the outcome of colorectal cancer, and may participate in tumour progression in lung cancer possibly by modulating CD8 tumour infiltrating T cells and PD-L1 expression. In this review, we first briefly present the biological and immunological functions of IL-38, and then discuss the important roles of IL-38 in various types of diseases, and finally highlight its use in therapeutic strategies.

The Common Cold and Influenza in Children: To Treat or Not to Treat?

The common cold, which is mostly caused by respiratory viruses and clinically represented by the symptoms of acute respiratory viral infections (ARVI) with mainly upper respiratory tract involvement, is an important problem in pediatric practice. Due to the high prevalence, socio-economic burden, and lack of effective prevention measures (except for influenza and, partially, RSV infection), ARVI require strong medical attention. The purpose of this descriptive literature review was to analyze the current practical approaches to the treatment of ARVI to facilitate the choice of therapy in routine practice. This descriptive overview includes information on the causative agents of ARVI. Special attention is paid to the role of interferon gamma as a cytokine with antiviral and immunomodulatory effects on the pathogenesis of ARVI. Modern approaches to the treatment of ARVI, including antiviral, pathogenesis-directed and symptomatic therapy are presented. The emphasis is on the use of antibody-based drugs in the immunoprophylaxis and immunotherapy of ARVI. The data presented in this review allow us to conclude that a modern, balanced and evidence-based approach to the choice of ARVI treatment in children should be used in clinical practice. The published results of clinical trials and systematic reviews with meta-analyses of ARVI in children allow us to conclude that it is possible and expedient to use broad-spectrum antiviral drugs in complex therapy. This approach can provide an adequate response of the child's immune system to the virus without limiting the clinical possibilities of using only symptomatic therapy.

Medical appropriateness and economics of nucleic acid amplification testing for infectious diseases.

It has become commonplace to assume that nucleic acid amplification tests (NAATs) represent the gold standard for all infectious disease diagnostic testing. This proposition has become increasingly entrenched recently, as these tests can now be done, in comparison to even just a few years ago, relatively inexpensively and with rapid analytic turnaround times. Many can even be performed at the point of care by individuals without technical backgrounds. But there may be a dark underside to this proposition. Could these tests be too sensitive? Are they always "fit for purpose"? Should they trump clinical judgement? Do they have untoward impacts on antimicrobial therapy? Could the profit motive - by manufacturers and by laboratories - be fueling the explosive expansion of NAATs? In this article, we will explore these questions in regard to several specific NAAT examples - Group A Streptococcus, Influenza, SARS-CoV-2, respiratory panels, and sexually transmitted disease panels.