Viremia defined as detectable SARS-CoV-2 RNA in the blood is a potential marker of disease severity and prognosis in COVID-19 patients. Here, we determined the frequency of viremia in serum of two independent COVID-19 patient cohorts within the German National Pandemic Cohort Network (German: Nationales Pandemie Kohorten Netzwerk, NAPKON) with diagnostic RT-PCR against SARS-CoV-2. A cross-sectional cohort with 1122 COVID-19 patients (German: Sektorenuebergreifende Platform, SUEP) and 299 patients recruited in a high-resolution platform with patients at high risk to develop severe courses (German: Hochaufloesende Plattform, HAP) were tested for viremia. Our study also involved a comprehensive analysis and association of serological, diagnostic, and clinical parameters of the NAPKON medical dataset. Prevalence of viremia at the recruitment visit was 12.8% (SUEP) and 13% (HAP), respectively. Serological analysis revealed that viremic patients had lower levels of SARS-CoV-2 specific antibodies as well as lower neutralizing antibodies compared to aviremic patients. Viremia was associated with severity (<0.0001 SUEP; 0.002 HAP) and mortality of COVID-19 (both cohorts <0.0001) compared to aviremic patients. While rare, viremia was also detected in patients with mild disease (0.7%). In patients of the SUEP cohort with acute kidney disease (p = 0.0099) and hematooncological conditions (p = 0.0091), viremia was detected more frequently. Compared to the aviremic group, treatment with immunomodulating drugs as well as elevated levels of inflammatory markers in the blood was more frequent in the viremic group. In conclusion, our analysis revealed that detectable viremia correlates with hyperinflammatory conditions and higher risk for severe COVID-19 disease.

Emergence of viruses cause unprecedented challenges and thus leading to wide-ranging consequences today. The world has faced massive disruptions like COVID-19 and continues to suffer in terms of public health and world economy. Fighting with this emergence of viruses and its reemergence plays a critical role in the health care industry. Identification of novel virus-drug associations is a vital step in drug discovery. Prediction and prioritization of novel virus-drug associations through computational approaches is an alternative and best choice considering the cost and risk of biological experiments. This study proposes a method, KR-AEVDA that relies on k-nearest neighbor based reliable negative sample selection and autoencoder based feature extraction to explore promising virus-drug associations for further experimental validation. The method analyzes complex relationships among drugs and viruses by investigating similarity and association data between drugs and viruses. It generates feature vectors from the similarity data, and reliable negative samples are extracted through an effective distance-based algorithm from the unlabeled samples in the dataset. Then high level features are extracted via an autoencoder and is fed to an ensemble classifier for inferring novel associations. Experimental results on three different datasets showed that KR-AEVDA reliably attained better performance than other state-of-the-art methods. Molecular docking is carried out between the top-predicted drugs and the crystal structure of the SARS-CoV-2's main protease to further validate the predictions. Case studies for SARS-CoV-2 illustrate the effectiveness of KR-AEVDA in identifying potential virus-drug associations.

SARS-CoV-2 is a neurotrophic and pro-inflammatory virus, with several acute and more persistent neuropsychiatric sequelae reported. There are limited data from African cohorts and few acute illness biomarkers of persistent neuropsychiatric symptoms.

To examine the association of neuropsychiatric outcomes with clinical illness severity, systemic inflammation, cardiovascular and renin-angiotensin-system (RAS) biomarkers. Second, to determine the prevalence of neuropsychiatric symptoms in a cohort of South African SARS-CoV-2 PCR positive patients at least six months following infection/hospitalization.

SARS-CoV-2 PCR positive patients were recruited prospectively from Cape Town, South Africa, including hospitalized patients from ancestral, beta and delta-dominant COVID-19 waves (pre-vaccine rollout); and asymptomatic/mild SARS-CoV-2 positive patients. The 96-protein O-link inflammation and cardiovascular panels, RAS fingerprinting, and antibody responses were measured in serum samples collected at peak severity and recovery (>3 months post-infection). Telephonic interviews were conducted at least six months post infection/hospitalization. Validated measures employed were: WHO Self-Report Questionnaire (SRQ-20), Generalized Anxiety Disorder Scale (GAD-7), Chalder Fatigue Scale (CFS-11) and Telephonic Montreal Cognitive Assessment (T-MoCA).

Ninety-seven participants completed telephonic interviews. The median (IQR) age was 48 (37-59) years, and 54 % were female. There were no significant associations between neuropsychiatric outcomes and illness severity, systemic inflammation, cardiovascular and/or renin-angiotensin-system (RAS) biomarkers from either peak illness or recovery samples. More than half of this SA COVID-19 cohort had one or more persistent neuropsychiatric symptoms >6 months post vaccine-naïve infection. On the T-MoCA, 44 % of participants showed evidence of cognitive and/or memory impairments.

The high prevalence of persistent neuropsychiatric symptoms in this African cohort supports ongoing attention to long COVID. Acute and early serum protein biomarkers were not associated with persistent neuropsychiatric outcomes post-COVD-19.

Neutralizing autoantibodies against type I interferons were strongly linked to severe COVID-19 in unvaccinated patients; however, this has yet to be evaluated in vaccinated individuals.

To analyze how these autoantibodies influences disease variability in vaccine breakthrough COVID-19 pneumonia patients.

Clinical and laboratory data; autoantibodies blocking interferon-α2 and -ω; and humoral response to SARS-CoV-2 vaccine were collected from all vaccinated COVID-19 pneumonia patients admitted from April 2021 to December 2022 at Bellvitge University Hospital, Spain.

458 patients developed COVID-19 pneumonia despite an appropriate antibody response to SARS-CoV-2 vaccination. Autoantibodies neutralizing interferons were significantly more prevalent in patients with critical pneumonia compared to those with milder forms (8.8 % vs. 3.6 %; p = 0.037). Having these autoantibodies was an independent predictor for critical COVID-19 pneumonia (OR 2.88 [95 %CI 1.18-6.98]).

Vaccination considerably reduces the severity of COVID-19; however, patients with type I interferon autoantibodies remain at increased risk of severe disease.

The coronavirus disease 2019 (COVID-19) pandemic has disproportionately impacted immunocompromised hosts, leading to higher morbidity and mortality. The clinical outcomes have varied based on the degree of immunosuppression, treatment availability, severe acute respiratory syndrome coronavirus 2 variants, and vaccination status. This review discusses the evolving epidemiology, clinical presentation, treatment, and prevention strategies for COVID-19 in immunocompromised populations, including patients living with human immunodeficiency virus, solid organ transplant, and hematopoietic stem cell transplant recipients.

Widespread vaccination, hybrid immunity, and reduced pathogenicity with circulating Omicron variants have decreased the rate of severe coronavirus disease 2019 (COVID-19) outcomes in the general population. Certain patients with COVID-19 remain at high risk for severe outcomes. Clinicians must individualize treatments based on expected benefits and relative harms for patients with mild-to-moderate COVID-19. Guideline-directed therapy for severe and critical COVID-19 has remained static over the last couple of years. Data on immunomodulatory agents have improved our understanding of the management of severe and critical COVID-19, yet uncertainty remains on the role and timing of these agents in the Omicron era.

The SARS-CoV-2 outbreak highlights the persistent vulnerability of humanity to epidemics and emerging microbial threats, emphasizing the lack of time to develop disease-specific treatments. Therefore, it appears beneficial to utilize existing resources and therapies. Computational drug repositioning is an effective strategy that redirects authorized drugs to new therapeutic purposes. This strategy holds significant promise for newly emerging diseases, as drug discovery is a lengthy and expensive process. Through this study, we present an ensemble method based on the convolutional neural network integrated with genetic algorithm and deep forest classifier for virus-drug association prediction (CGDVDA). We generated feature vectors by combining drug chemical structure and virus genomic sequence-based similarities, and extracted prominent deep features by applying the convolutional neural network. The convoluted features are optimized using the genetic algorithm and classified using the ensemble deep forest classifier to predict novel virus-drug associations. The proposed method predicts drugs for COVID-19 and other viral diseases in the dataset. The model could achieve ROC-AUC scores of 0.9159 on fivefold cross-validation. We compared the performance of the model with state-of-the-art approaches and classifiers. The experimental results and case studies illustrate the efficacy of CGDVDA in predicting drugs against viral infectious diseases.

Aqueous two-phase systems (ATPS) have been used to purify a range of biomolecules, including small molecules, monoclonal antibodies, viruses, and whole cells. They are known for selective separations, creating a stabilizing, low-shear environment, and high yields. Recently, as biomanufacturing attempts to adopt continuous processing, attention has shifted to ATPS for its ability to operate fully continuously while incurring lower costs than many chromatographic methods. But despite 60 years of exploration and development, the complex network of interlinked driving forces controlling these separations has prevented robust development of process understanding, and most ATPS separations are still optimized using slow and costly manual screening methods. As a result, industry has been unwilling to adopt ATPS. Fortunately, a growing body of literature is developing statistical and mechanistic models of ATPS to predict liquid-liquid equilibria and separations with reduced experimental burden. This review surveys the application of these models to ATPS, comparing their progress and potential to promote rapid development of bioseparations in the near and long term. The discussion evaluates the adaptability of statistical tools, like response surface methodology and artificial neural networks, and contrasts it with the process understanding generated through application of semi-empirical thermodynamic models. Strategies are explored to automate optimization of separations for new biomolecules using these models to create artificial data. By understanding the landscape of models applied to ATPS, this review will start a discussion about bringing this technology closer to commercialization and enabling continuous processing on a broader scale.

Nuclear export protein 1, also known as XPO1, plays a crucial role in cellular homeostasis and assists in the nucleocytoplasmic transfer of ribonucleic acids (RNAs) and proteins. In addition, this nuclear export receptor is essential for the export of a variety of cargo molecules, such as proteins implicated in the immune response, tumor suppression, and cell cycle regulation. XPO1 has emerged as a promising target to disrupt the life cycles of multiple viruses and treat cancers. In our current work, we used a computational approach consisting of pharmacophore-assisted virtual screening complemented by molecular docking, molecular dynamics, and solvation-based free-energy studies to identify new inhibitors of the XPO1 protein. The identified compounds displayed highly stable RMSD plots, hydrogen bonding interactions, and relatively good binding affinities in both docking and free energy studies. These molecules were validated in vitro against SARS-CoV-2 and cancer cell lines. The study identified novel inhibitors of the XPO1 protein with both antiviral and anticancer activities.

A major hindrance to the identification of new drug targets and the large-scale testing of new or existing compound libraries against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is that research on the virus is restricted to biosafety level 3 (BSL-3) laboratories. In such cases, BSL-2 surrogate systems or chimeric and attenuated versions of the virus are developed for safer, faster, and cheaper examination of the stages of the virus life cycle and specific drug targets. In this study, we describe a BSL-2 chimeric viral system utilizing a Sindbis virus background as a tool to study one such target, the SARS-CoV-2 Envelope (E) protein channel activity. This protein is fully conserved between SARS-CoV and SARS-CoV-2 variants of concern (VOCs), except for a threonine to isoleucine mutation in the Omicron variant, making the E ion channel domain an attractive antiviral target for combination therapy. Using a BSL-2-chimeric system, we have been able to show similar inhibition profiles using channel inhibitors as previously reported for E-channel inhibition in authentic SARS-CoV-2. This system has the potential to allow faster initial screening of E-channel inhibitors and can be useful in developing broad-spectrum antivirals against viral channel proteins.IMPORTANCEDespite its importance in viral infections, no antivirals exist against the ion channel activity of the SARS-CoV-2 Envelope (E) protein. The E protein is highly conserved among SARS-CoV-2 variants, making it an attractive target for antiviral therapies. Research on SARS-CoV-2 is restricted to BSL-3 laboratories, creating a bottleneck for screening potential antiviral compounds. This study presents a BSL-2 chimeric system using a Sindbis virus background to study the ion channel activity of the E protein. This novel BSL-2 system bypasses this limitation, offering a safer and faster approach for the initial screening of ion channel inhibitors. By replicating the channel inhibition profiles of authentic SARS-CoV-2 in a more accessible system, this research paves the way for the development of broad-spectrum antivirals against viral channel proteins, potentially expediting the discovery of life-saving treatments for COVID-19 and other viral diseases.

Procalcitonin (PCT) is recognized as an inflammatory biomarker, often elevated in COVID-19 pneumonia alongside other biomarkers. Understanding its association with severe outcomes and comparing its predictive ability with other biomarkers is crucial for clinical management.

This retrospective multicenter observational study aimed to investigate the association between PCT levels and adverse outcomes in hospitalized COVID-19 patients. Additionally, it sought to compare the predictive performance of various biomarkers.

The study analyzed data from the Society of Critical Care Medicine (SCCM) Viral Infection and Respiratory Illness Universal Study (VIRUS) registry, comprising COVID-19 patients hospitalized across multiple Mayo Clinic sites between March 2020 and June 2022.

A total of 7851 adult COVID-19 patients were included. Patients were categorized into 6 groups based on the worst WHO ordinal scale. Multivariate models were constructed using peak biomarker levels within 72 hours of admission, adjusted for confounders.

Elevated PCT levels were independently associated with increased odds of adverse outcomes, including ICU admission (adjusted odds ratio [aOR] 1.32, 95%CI 1.27-1.38), IMV requirement (aOR 1.35, 95%CI: 1.28-1.42), and in-hospital mortality (aOR 1.30, 95%CI: 1.22-1.37). A 3.48-fold increase in IMV requirement and 3.55 times increase in in-hospital mortality were noted with peak PCT ⩾ 0.25 ng/ml. Similar associations were observed with other biomarkers like NLR (AUC 0.730), CRP, IL-6, LDH (AUC 0.800), and D-dimer (AUC 0.719). Models incorporating NLR, LDH, D-dimer, and PCT demonstrated the highest predictive accuracy, with a combined model exhibiting an area under the curve (AUC) of 0.826 (95%CI 0.803-0.849).

Higher PCT levels were significantly linked to worse outcomes in COVID-19 patients, emphasizing its potential as a prognostic marker. Biomarker-based predictive models, particularly those including PCT, showed promising utility for risk assessment and clinical decision-making. Further prospective studies are warranted to validate these findings on a larger scale.

The coronavirus disease 2019 (COVID-19) global health crisis, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has presented unprecedented challenges to global healthcare systems, leading to rapid advances in treatment development. This review comprehensively examines the current therapeutic approaches for managing COVID-19, including direct-acting antivirals, immunomodulators, anticoagulants, and adjuvant therapies, as well as emerging and experimental approaches. Direct-acting antivirals target various stages of the viral life cycle, offering specific intervention points, while immunomodulators aim to modulate the host's immune response, reducing disease severity. Anticoagulant therapies address the coagulopathy frequently observed in severe cases, and adjuvant treatments provide supportive care to improve overall outcomes. We also explore the challenges and limitations of implementing these treatments, such as drug resistance, variable patient responses, and access to therapies, especially in resource-limited settings. The review also discusses future perspectives, including the potential of next-generation vaccines, personalized medicine, and global collaboration in shaping future COVID-19 treatment paradigms. Continuous innovation, combined with an integrated and adaptable approach, will be crucial to effectively managing COVID-19 and mitigating the impact of future pandemics.

The single nucleotide polymorphism rs12979860 is associated with the production of IFNλ4, a type III interferon, which offers protection from viral infection via its proinflammatory properties. We investigated if a genetically determined increase in IFNλ4 affects disease progression in SARS-CoV-2. This prospective, single-center study involved critically ill SARS-CoV-2 patients admitted to the intensive care unit. We performed genotyping for rs12979860 and analyzed daily laboratory data. Genotype frequencies were compared with an external validation cohort. Critically ill individuals with COVID-19 (n = 184; 29.3% women) were included. Median age was 63 years. The TT genotype was present in 11%, CT in 48% and CC in 41%. At baseline, CRP, ferritin, transferrin and neopterin did not differ significantly between groups. Longitudinal analysis revealed significant genotype-dependent differences in CRP, ferritin and neopterin with the highest peak in TT patients after 10-15 days. A higher need for renal replacement therapy (31.6% vs. 11.7%, p = 0.044) and mechanical ventilation (22 days vs. 15 days, p = 0.018) was observed in the TT group. The SNP rs12979860 near IFNL4 is associated with distinct inflammatory trajectories in critically ill COVID-19 patients. Genetic determinants of the immune response influence the severity of inflammation and clinical outcomes in severe COVID-19.

In November 2020, the Food and Drug Administration issued an Emergency Use Authorization for baricitinib, a Janus Kinase protein inhibitor, for hospitalized children and adults with COVID-19 requiring supplemental oxygen, but safety data for this pediatric indication is lacking.

This retrospective case series describes patients aged younger than 21 years treated with baricitinib for severe COVID-19 between 2021 and 2022. Patient characteristics, treatments, adverse events, reasons for early discontinuation of baricitinib, durations of oxygen supplementation and hospitalization, and complications were recorded.

There were 37 patients who received baricitinib. Median age was 16 years (range 1-20). All had a comorbidity (59% obesity, 5% malignancy), and 76% were cared for in the intensive care unit. All received remdesivir (median 5 days; range: 2-11), and 34 (92%) received corticosteroids (median 6 days; range: 1-10). Median duration of baricitinib was 6 days (range 3-14). Baricitinib was discontinued early for clinical improvement (2), and adverse events (7; 6 elevated liver enzymes [only 1 meeting discontinuation criteria), 1 thrombocytosis]). One patient had deep vein thrombosis without pulmonary embolism, 5 patients had concurrent infections (4 bacterial, 1 fungal, 2 herpes simplex virus reactivation). All adverse events were resolved. There were no deaths. Median hospitalization was 7 days (range 2-108) and mechanical ventilation was 4.5 days (range 1-86 days). Two patients (5%) were discharged with supplemental oxygen and one with a tracheostomy.

Baricitinib appears safe in children hospitalized for severe COVID-19. Most early baricitinib discontinuation for abnormal laboratory studies was secondary to provider caution.

Severe coronavirus outbreaks, including SARS, MERS, and COVID-19, have underscored the urgent need for effective antiviral therapies. This study evaluated the antiviral activity of biflavanones isolated from Ouratea spectabilis-specifically ouratein (Our-) A, B, C, and D-against murine hepatitis virus (MHV-3) and human SARS-CoV-2. Cells infected with MHV-3 or SARS-CoV-2 were treated with ourateins, and viral replication was assessed using plaque assays. Mice infected with MHV-3 were treated with Our-D either orally or intraperitoneally. Key assessments included leukocyte counts, cytokine and chemokine levels, histological analysis, and survival rates. The mechanism of action was explored through in silico and in vitro studies focused on the binding and inhibition of the main protease (Mpro). Our-D significantly inhibited the replication of both viruses, with a selective index of 2.5 for MHV-3 and 14.9 for SARS-CoV-2. In vivo, Our-D reduced leukocyte infiltration in the lungs, decreased CCL2 levels, increased IL-10, and lowered plasma IL-6 and CXCL1 levels. Additionally, Our-D mitigated lung damage, partially restored betacoronavirus-induced lymphopenia, and reduced viral loads in the lungs, heart, and spleen, ultimately improving survival in mice. In silico studies revealed that Our-A and Our-C had strong binding affinity for Mpro, and both significantly inhibited Mpro activity in vitro, unlike Our-D. Our-D protected mice from coronavirus infection by modulating the inflammatory response and reducing viral loads, with minimal effect on Mpro inhibition, suggesting alternative mechanisms for its antiviral activity.

There is limited evidence on clinical outcomes and treatment pattern in Japanese patients with severe chronic kidney disease (CKD), hospitalized for coronavirus disease-2019 (COVID-19). We aimed to describe patient characteristics, treatment pattern, and clinical outcomes in Japanese patients with severe CKD, hospitalized for COVID-19 who received remdesivir (RDV).

We used the anonymized claims database from Medical Data Vision Co., Ltd., Japan. The analysis included patients aged ≥ 18 years with severe CKD, hospitalized for moderate to severe COVID-19, and administered ≥ 1 dose of RDV between October 2021 and September 2023. All-cause inpatient mortality, disease progression, and recovery up to 56 days from hospitalization were evaluated.

Data of 847 patients were analyzed (mean age 73.0 ± 14.1 years). Median (Q1-Q3) time to RDV initiation was 1.0 day (1.0-2.0) from hospitalization and treatment duration was 5.0 days (3.0-5.0). At RDV initiation, 44.27% patients required non-invasive positive pressure ventilation/high or low flow oxygen; 4.25% required invasive mechanical ventilation/extracorporeal membrane oxygenation/intensive care unit hospitalization. Proportion of patients with all-cause mortality was 11.45% (stage 4, 14.89%; stage 5, 10.47%) by 28 days and 12.28% (stage 4, 16.49%; stage 5, 11.08%) by 56 days. At 28 days, 12.28% had disease progression and 72.14% recovered.

Most patients with severe CKD received RDV immediately after hospitalization. The majority of patients recovered by 28 days. The study provided insights into RDV treatment in inpatient settings, which could contribute to the discussion on standard of care in this population in Japan.

Enteroviruses (EV) usually cause acute, mild, self-limiting disease. Chronic infections with EVs are rare, and typically occur in patients with immunodeficiency, posing a high risk of severe outcomes. We report a rare case of chronic diarrhea caused by coxsackievirus A1 (CVA1) (from EV-C species) infection in a patient with a common variable immunodeficiency, who was on treatment with pooled intravenous immunoglobulin (IVIG) from the Netherlands. To explore treatment options, we assessed the presence of neutralizing antibodies (nAbs) against CVA1 in pooled IVIG from South Africa, where EV-Cs are prevalent, and tested the antiviral efficacy of US Food and Drug Administration-approved drugs like fluoxetine, itraconazole, ribavirin, and remdesivir (RDV) against CVA1 in vitro. Both Dutch and South African IVIG showed low nAb titers against CVA1. The patient, treated with Dutch IVIG, also received a combination of amantadine and fluoxetine, which were discontinued due to side effects. Among the drugs tested, only RDV significantly inhibited CVA1 replication in rhabdomyosarcoma (RD) cells. This in vitro efficacy was not reflected by a favorable clinical response after treatment of the patient with RDV. In concordance with unfavorable antiviral response in the patient, preliminary tests on a co-culture model containing isogenic human intestinal cells and intestinal fibroblasts showed no significant reduction in CVA1 RNA copies after RDV administration. In conclusion, our results showed that repurposing of drugs that have shown in vitro efficacy does not translate well to the patients, and this is also reflected in a more physiologically relevant model of the human intestine.

The coronavirus disease 2019 (COVID-19) pandemic has exerted a catastrophic impact on public health. Meanwhile, the seasonal influenza outbreak overlaps with the current pandemic wave. There is still an urgent need to develop effective therapeutic agents for the treatment of co-infection of multiple respiratory viruses. This study aimed to investigate antiviral effects of EIDD-2801, an orally bioavailable ribonucleoside analog, and its potent therapeutic effects in co-infection of multiple respiratory viruses.

BALB/c mice and hamsters were infected with IFV or SARS-CoV-2, then were dosed orally with EIDD-2801 to measure the antiviral effects of EIDD-2801. Viral replication and mRNA transcription were evaluated by quantitative polymerase chain reaction (qPCR) and protein expression by Western Blot. Influenza viral titer was assessed using EID50 assay.

EIDD-2801 was found to be significantly effective against influenza A virus and influenza B virus. The antiviral activity against SARS-CoV-2 and further co-infection with influenza virus was also distinct. EIDD-2801 had potent antiviral effects against multiple respiratory viruses both in vitro and in vivo.

This study demonstrated that the small-molecule compound EIDD-2801, an orally available broad-spectrum antiviral agent, significantly inhibited the infection of influenza virus and SARS-CoV-2 and effectively protected animals from lethal influenza virus co-infection.

The COVID-19 pandemic, caused by the virus SARS-CoV-2 infection, has underscored the critical importance of rapid and accurate therapeutics. The neutralization of SARS-CoV-2 is paramount in controlling the spread and impact of COVID-19. In this context, the integration of aptamers and aptamer-related nanotherapeutics presents a valuable and scientifically significant approach. Despite the potential, current reviews in this area are often not comprehensive and specific enough to encapsulate the full scope of therapeutic principles, strategies, advancements, and challenges. This review aims to fill that gap by providing an in-depth examination of the role of aptamers and their related molecular medicine in COVID-19 therapeutics. We first introduce the unique properties, selection, and recognition mechanism of aptamers to bind with high affinity to various targets. Next, we delve into the therapeutic potential of aptamers, focusing on their ability to inhibit viral entry and replication, as well as modulate the host immune response. The integration of aptamers with nucleic acid nanomedicine is explored. Finally, we address the challenges and future perspectives of aptamer and nucleic acid nanomedicine in COVID-19 therapeutics, including issues of stability, delivery, and manufacturing scalability. We conclude by underscoring the importance of continued research and development in this field to meet the ongoing challenges posed by COVID-19 and potential future pandemics. Our review will be a valuable resource for researchers and clinicians interested in the latest developments at the intersection of molecular biology, nanotechnology, and infectious disease management.

Long covid describes a syndrome of persistent symptoms following COVID-19 and is responsible for substantial healthcare and economic burden. Currently, no effective treatments have been established. Ashwagandha (Withania somnifera (L.) Dunal) is a medicinal herb traditionally used in India for its immune-strengthening and anti-inflammatory properties. Withanolides, a family of steroid-derived molecules unique to Ashwagandha, have been shown to modulate inflammatory pathways in animal models, and several small randomised trials in humans support its effectiveness for reducing symptoms that are also associated with long covid. Therefore, this study aims to assess whether Ashwagandha is effective and safe for improving functional status and reducing symptom burden in adults living with long covid.

A randomised double-blind placebo-controlled trial will be performed at participating general practice (GP) surgeries and long covid clinics across the UK. Individuals diagnosed with long covid will be screened for eligibility and then randomised 1:1 to take 1000 mg daily of Ashwagandha root extract tablets (standardised to <0.9% withanolides) or matching placebo tablets for 3 months (target, n = 2500). Monthly online surveys will be performed to collect patient-reported outcomes, and monthly safety monitoring, including liver function tests, will be conducted by clinical site teams. The primary outcome of the Post-COVID Functional Status Scale score at 3 months will be assessed by baseline-adjusted ordinal logistic regression, according to a pre-published statistical analysis plan. The secondary outcomes included validated quality of life and long covid symptom scales, work status and productivity and adverse events. The trial has been approved as a Clinical Trial of an Investigational Medicinal Produce by the Medicines and Healthcare Regulatory Authority and by the NHS Research Ethics Committee and Health Research Authority.

Treatments for long covid are urgently needed. This trial will robustly evaluate the safety and efficacy of a candidate treatment with a promising efficacy and safety profile. If found to be effective, the findings will likely influence treatment guidelines and improve health outcomes in those living with long covid.

This trial was pre-registered on 15/08/2022: ISRCTN12368131.

Bradycardia is not currently described as an adverse effect in prescribing information for remdesivir but has been reported postapproval. Therefore, effects on heart rate (HR) and bradycardia incidence after remdesivir initiation may be underrecognized by clinicians.

To evaluate HR and bradycardia incidence after remdesivir initiation among patients with COVID-19.

This was a single-center, retrospective cohort study between May 1, 2020 and December 1, 2021. Hospitalized patients eligible for inclusion were ≥18 years and received > 1 dose of remdesivir. Patients were excluded if they were pregnant, incarcerated, or received new medications associated with bradycardia. The primary outcome was to evaluate differences in median HR among patients preremdesivir (up to 24 hours prior to remdesivir) and postremdesivir (first dose through the treatment duration). Secondary outcomes included bradycardia episodes postremdesivir, nadir HR postremdesivir, and interventions for bradycardia management. Variables to assess postremdesivir bradycardia were considered in multivariate logistic regression if they had a P < 0.1 on univariate analysis.

Among 514 patients, 328 were included. Most were male (53.4%), had severe COVID-19 (59.8%), and median (interquartile range [IQR]) age was 62 (23.7) years. Median (IQR) remdesivir duration was 4.9 (1.5) days. Median (IQR) HR was significantly lower postremdesivir than preremdesivir (74 (15) vs 87 (19), P < 0.001). There were significantly more bradycardia episodes postremdesivir than before (48.8% [160/328] vs (2.4% [8/328]), P < 0.001). Among 48.8% (160/328) of patients with bradycardia postremdesivir, median (IQR) nadir HR was 53 (6.8). Remdesivir was discontinued early in 1 patient (0.6%). In multivariate logistic regression, remdesivir duration (odds ratio [OR] = 1.26, 95% confidence interval [CI] = 1.04 to 1.54, P = 0.019) and median preremdesivir HR (OR = 0.96, 95% CI = 0.94 to 0.97, P < 0.001) were identified as significant predictors for bradycardia.

Remdesivir was associated with a significantly lower HR and higher incidence of bradycardia among hospitalized patients with COVID-19. These data may help improve recognition and management of these remdesivir-associated effects during COVID-19 treatment.

The COVID-19 pandemic highlighted the serious threat that coronaviruses have on public health. Because coronavirus continuously undergoes cross-species transmission, additional therapeutic agents and targets are urgently needed. Here, we show that a 3-deazapurine ribonucleoside, 3-Deazaguanosine (C3Guo, 2), has potent antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Unexpectedly, C3Guo (2) does not act as an inhibitor of RNA-dependent RNA polymerase (RdRp), which is the therapeutic target of two key nucleoside/nucleotide inhibitors approved for the treatment of COVID-19 (Remdesivir and Molnupiravir); instead, it seems to function by targeting the capping machinery of viral RNA. In hamsters infected with SARS-CoV-2, administration of 2 markedly reduced infectious viral titers, and prevented the development of COVID-19 pneumonia better than Molnupiravir. The potency of 2 against SARS-CoV-2 underscores its potential as an effective therapeutic agent for COVID-19 and future zoonotic coronavirus infections and raises the possibility of antiviral nucleoside analogs with alternative therapeutic targets to RdRp.

Given the recurrent waves of COVID-19 and the emergence of new viral infections, optimizing the potential of remdesivir as an antiviral agent is critical. While several reviews have explored the efficacy of remdesivir, few have comprehensively addressed its challenges, such as the necessity for intravenous infusion, suboptimal lung accumulation, and safety concerns related to its formulation. This review critically examines these challenges while proposing innovative solutions and effective combinations with other antiviral agents and repurposed drugs. By highlighting the role of complex generics, we aim to enhance therapeutic efficacy in ways not previously discussed in existing literature. Furthermore, we address the development of novel drug delivery systems which specifically aim to improve remdesivir's pharmacological profile. By analyzing recent findings, we assess both the successes and limitations of current approaches, providing insights into ongoing challenges and strategies for further optimization. This review uniquely focuses on targeted drug delivery systems and innovative formulations, thereby maximizing remdesivir's therapeutic benefits and broadening its application in combating emerging viral threats. In doing so, we fill a critical gap in literature, offering a comprehensive overview that informs future research and clinical strategies.

The clinical development of therapeutics for COVID-19 proceeded at an extraordinary pace. Given the lack of studies evaluating this experience systematically, we analyzed the clinical development methods for COVID-19 therapeutics to determine strategies for shortening the clinical development period in preparation for future pandemics.

We confirmed the US-FDA review documents for fourteen products that underwent Emergency Use Authorization (EUA) in the US during the COVID-19 pandemic to examine the time required for clinical development and regulatory review and the submitted data for EUA.

Six of the fourteen products with clinical study data for other indications were evaluated in fewer studies than new molecular entities. The application data for each product included the stipulated content, and placebo-controlled comparative studies were included for all products. Clinical development measures were adopted, including adaptive protocol design, nonsequential phase development, and clinical dose adaptation based on non-clinical study results.

Products with clinical study data for other indications are advantageous for early approval. However, early approval of new molecular entities is also important because they may not be sufficiently effective against new infectious diseases. It would be effective to approve a product promptly for a limited target population at first and then gradually expand it as data becomes more abundant. To prepare for future pandemics, we recommend establishing a framework for identifying candidates from existing products, managing and disseminating information in emergencies at various levels, and clarifying the conditions for applying regulatory flexibility to encourage pharmaceutical companies to make early decisions regarding clinical development.

In the post-acute coronavirus disease 2019 (COVID-19) period, patients with asthma had a significantly higher risk of cough than patients without a history of asthma. In particular, cases with persistent cough were increased during the Omicron variant epidemic. In this study, we evaluated the efficacy of ensitrelvir for the treatment of cough associated with COVID-19 Omicron variants in patients with asthma. This follows the Strengthening the Reporting of Observational Studies in Epidemiology statement. A total of 223 patients were registered in this study: 121 patients chose ensitrelvir, and 102 patients chose symptomatic treatment. Cough severity, frequency, and cough-specific quality of life were evaluated using the Japanese version of the Leicester Cough Questionnaire (J-LCQ). J-LCQ documented at baseline on days 4, 7, and 14 for all patients showed a steady improvement over time in both groups. In the mixed model for repeated measures model, which accounts for repeated measurements, the change in J-LCQ score from baseline was 2.1 points higher in the ensitrelvir group (P <0.001). Additionally, patients who were using triple inhaled therapy at baseline showed a 2.3-point higher change in J-LCQ score from baseline (P <0.001). Multiple regression analysis was performed at days 4, 7, and 14, with the change in J-LCQ score from baseline as the dependent variable. Ensitrelvir was associated with scores that were 3.1 points higher on day 4, 3.5 points higher on day 7, and 2.0 points higher on day 14 compared with symptomatic treatment (P <0.001 for all). In conclusion, our results demonstrated that early administration of ensitrelvir may be effective as a treatment for cough due to the COVID-19 Omicron variant.

We evaluated the efficacy of ensitrelvir for the treatment of cough due to coronavirus disease 2019 (COVID-19) Omicron variant in patients with asthma. A total of 223 patients were registered in this study: 121 patients chose ensitrelvir, and 102 patients chose symptomatic treatment. Cough severity, frequency, and cough-specific quality of life were evaluated using the Japanese version of the Leicester Cough Questionnaire (J-LCQ). Multiple regression analysis was performed at days 4, 7, and 14, with the change in J-LCQ score from baseline as the dependent variable. Ensitrelvir was associated with scores that were 3.1 points higher on day 4, 3.5 points higher on day 7, and 2.0 points higher on day 14 compared with symptomatic treatment (P <0.001 for all). Our results demonstrated that early administration of ensitrelvir may be effective as a treatment for cough due to the COVID-19 Omicron variant.

Renin-angiotensin system (RAS) dysregulation is an important component of the complex pathophysiology of SARS-CoV-2 and other coronavirus infections. Thus, angiotensin-converting enzyme 2 (ACE2), the entry receptor and key to the alternative RAS, was proposed as a severity/prognostic biomarker for risk-stratification. However, experimental RAS data from diverse cohorts are limited, particularly analyses integrating RAS with immune biomarkers. Participants (n = 172) in Cape Town were sampled longitudinally (including a recovery timepoint [> 3-month]), across WHO asymptomatic to critical severity. Using fluorometric assays and LC-MS/MS RAS Fingerprinting®, results show serum ACE1 activity significantly decreases with increasing COVID-19 severity (P < 0.01) and mortality (P < 0.05), while increased ACE2 activity is associated with worse severity (P < 0.01). Neither enzyme activity correlates with viral load proxy or nasal ACE mRNA levels. ACE1 and ACE2 activities were the most effective severity biomarkers compared to 96 established immune markers obtained via proximity extension assay, as demonstrated by principal component analysis. A multivariate variable selection model using random forest classification identified biomarkers discriminating COVID-19 severity (AUC = 0.82), the strongest being HGF, EN-RAGE, cathepsin L. Adding ACE1 activity and anti-SARS-CoV-2 antibody titres improved differentiation between ambulatory and hospitalised participants. Notably, RAS dysregulation has unique severity associations in coronavirus infections with implications for treatment and pathophysiological mechanisms.

Remdesivir (RDV) was the first antiviral approved for mild-to-moderate COVID-19 and for those patients at risk for progression to severe disease after clinical trials supported its association with improved outcomes. Real-world evidence (RWE) generated by artificial intelligence techniques could potentially expedite the validation of new treatments in future health crises. We aimed to use natural language processing (NLP) and machine learning (ML) to assess the impact of RDV on COVID19-associated outcomes including time to discharge and in-hospital mortality.

Using EHRead®, an NLP technology including SNOMED-CT terminology that extracts unstructured clinical information from electronic health records (EHR), we retrospectively examined hospitalized COVID-19 patients with moderate-to-severe pneumonia in three Spanish hospitals between January 2021 and March 2022. Among RDV eligible patients, treated (RDV+) vs untreated (RDV‒) patients were compared after propensity score matching (PSM; 1:3.3 ratio) based on age, sex, Charlson comorbidity index, COVID-19 vaccination status, other COVID-19 treatment, hospital, and variant period. Cox proportional hazards models and Kaplan-Meier plots were used to assess statistical differences between groups.

Among 7,651,773 EHRs from 84,408 patients, 6,756 patients were detected with moderate-to-severe COVID-19 pneumonia during the study period. The study population was defined with 4,882 (72.3%) RDV eligible patients. The median age was 72 years and 57.3% were male. A total of 812 (16.6%) patients were classified as RDV+ and were matched to 2,703 RDV‒ patients (from a total of 4,070 RDV‒). After PSM, all covariates had an absolute mean standardized difference of less than 10%. The hazard ratio for in-hospital mortality at 28 days was 0.73 (95% confidence interval, CI, 0.56 to 0.96, p = 0.022) with RDV‒ as the reference group. Risk difference and risk ratio at 28 days was 2.7% and 0.76, respectively, both favoring the RDV+ group. No differences were found in length of hospital stay since RDV eligibility between groups.

Using NLP and ML we were able to generate RWE on the effectiveness of RDV in COVID-19 patients, confirming the potential of using this methodology to measure the effectiveness of treatments in pandemics. Our results show that using RDV in hospitalized patients with moderate-to-severe pneumonia is associated with significantly reduced inpatient mortality. Adherence to clinical guideline recommendations has prognostic implications and emerging technologies in identifying eligible patients for treatment and avoiding missed opportunities during public health crises are needed.

The worldwide spread of new SARS-CoV-2 variants emphasizes the need to diversify existing therapeutic strategies. TMPRSS2, a host protease crucial for SARS-CoV-2 entry, has garnered significant research attention as a potential target for therapeutic intervention. Here, we optimized N-0385, a previously reported TMPRSS2 ketobenzothiazole-based peptidomimetic inhibitor, by screening 135 derivatives for target affinity and antiviral potency. Among the top candidates, N-0695 exhibited low nanomolar Ki values against three TTSPs associated with respiratory virus entry: TMPRSS2, matriptase, and TMPRSS13. Notably, N-0920 demonstrated exceptional potency in reducing SARS-CoV-2 variants EG.5.1 and JN.1 entry in Calu-3 cells, representing the first in cellulo picomolar inhibitor with EC50 values of 300 and 90 pM, respectively. Additionally, molecular modeling provided insights into the binding interactions between the compounds and their targets. This study underscores the effectiveness of our screening approach in refining an existing peptidomimetic scaffold to enhance selectivity and antiviral activity.

The antiviral agent, remdesivir, is adenosine analogue which is currently also used as anti-coronavirus disease 2019. Remdesivir also had anti-inflammatory effect which reduced pro-inflammatory cytokine production, and inhibition of the cyclic GMP-AMP synthase-STING pathway.

We evaluated the antiarthritic effects of remdesivir in a mouse model of High-fat diet (HFD) collagen-induced arthritis (CIA) and in fibroblast-like synoviocytes from patients with RA. Type II collagen was administered to DBA/1J mice to induce CIA. Vehicle or remdesivir was injected subcutaneously three times a week. During 7 weeks of treatment, the arthritis score and incidence were evaluated twice a week. Flow cytometry and confocal imaging were used to evaluate CD4 + T cells in the spleen. FLSs from patients with RA were stimulated in vitro with remdesivir and tumor necrosis factor (TNF)-α, and western blotting was used to measure the expression of STING and necroptosis-related markers.

Remdesivir administration suppressed the incidence and progression of arthritis in mice with CIA. Histological analysis revealed lower inflammation and cartilage damage scores in remdesivir-treated than in vehicle groups. Interleukin (IL)-17 + CD4 + T-cell differentiation was inhibited in the remdesivir-treated group. Furthermore, IL-17/-6/-1β, monocyte chemoattractant protein -1, and TNF-α expression was reduced in the remdesivir group. In vitro, remdesivir suppressed the expression of STING, nuclear factor-κB, RIPK3, and phosphorylated MLKL in RA-FLSs under TNF-α stimulation.

The antiviral agent remdesivir suppressed arthritis by regulating Th cell differentiation, pro-inflammatory cytokine expression, the STING pathway, and necroptosis.

Inborn errors of immunity (IEI) are congenital disorders of the immune system. Due to impaired immune system, they are at a higher risk to develop a more severe COVID-19 course compared to general population.

Herein, we aimed to systematically review various aspects of IEI patients infected with SARS-CoV-2. Moreover, we performed a meta-analysis to determine the frequency of COVID-19 in patients with different IEI.

Embase, Web of Science, PubMed, and Scopus were searched introducing terms related to IEI and COVID-19.

3646 IEI cases with a history of COVID-19 infection were enrolled. The majority of patients had critical infections (1013 cases, 27.8%). The highest frequency of critical and severe cases was observed in phenocopies of IEI (95.2%), defects in intrinsic and innate immunity (69.4%) and immune dysregulation (23.9%). 446 cases (12.2%) succumbed to the disease and the highest mortality was observed in IEI phenocopies (34.6%). COVID-19 frequency in immunodeficient patients was 11.9% (95% CI: 8.3 to 15.5%) with innate immunodeficiency having the highest COVID-19 frequency [34.1% (12.1 to 56.0%)]. COVID-19 case fatality rate among IEI patients was estimated as 5.4% (95% CI: 3.5-8.3%, n = 8 studies, I2 = 17.5%).

IEI with underlying defects in specific branches of the immune system responding to RNA virus infection experience a higher frequency and mortality of COVID-19 infection. Increasing awareness about these entities and underlying genetic defects, adherence to prophylactic strategies and allocating more clinical attention to these patients could lead to a decrease in COVID-19 frequency and mortality in these patients.

Racial and ethnic disparities in patient outcomes following COVID-19 exist, in part, due to factors involving healthcare delivery. The aim of the study was to characterize disparities in the administration of evidence-based COVID-19 treatments among patients hospitalized for COVID-19.

Using a large, US hospital database, initiation of COVID-19 treatments was compared among patients hospitalized for COVID-19 between May 2020 and April 2022 according to patient race and ethnicity. Multivariate logistic regression models were used to examine the effect of race and ethnicity on the likelihood of receiving COVID-19 treatments, stratified by baseline supplemental oxygen requirement.

The identified population comprised 317,918 White, 76,715 Black, 9297 Asian, and 50,821 patients of other or unknown race. There were 329,940 non-Hispanic, 74,199 Hispanic, and 50,622 patients of unknown ethnicity. White patients were more likely to receive COVID-19 treatments, and specifically corticosteroids, compared to Black, Asian, and other patients (COVID-19 treatment: 87% vs. 81% vs. 85% vs. 84%, corticosteroids: 85% vs. 79% vs. 82% vs. 82%). After covariate adjustment, White patients were significantly more likely to receive COVID-19 treatments than Black patients across all levels of supplemental oxygen requirement. No clear trend in COVID-19 treatments according to ethnicity (Hispanic vs. non-Hispanic) was observed.

There were important racial disparities in inpatient COVID-19 treatment initiation, including the undertreatment of Black patients and overtreatment of White patients. Our new findings reveal the actual magnitude of this issue in routine clinical practice to clinicians, policymakers, and guideline developers. This is crucial to ensuring equitable and appropriate access to evidence-based therapies.

The coronavirus disease 2019 (COVID-19) pandemic era saw numerous treatments authorized for emergency use by the United States (US) Food and Drug Administration (FDA). The purpose of the review was to determine if convalescent plasma, antivirals, or monoclonal antibodies are associated with serious adverse events (SAEs) and, if so, which specific populations are at risk.

PubMed, ClinicalTrials.gov, and the FDA submission database were searched through December 2023, and the Infectious Diseases Society of America guidelines, international COVID Network Meta-analysis database, and systematic reviews were reference mined to identify controlled studies with at least 1 US site. Reviewers abstracted study characteristics, number of patients experiencing each type of SAE, and methods of adverse event collection and reporting.

Fifty-four studies met inclusion criteria, including 31 randomized controlled trials. We found insufficient evidence of association of any SAE with antivirals and spike protein receptor-binding antibodies. In patients hospitalized with COVID-19, the monoclonal antibody tocilizumab, an interleukin 6 inhibitor, may be associated with elevated risk of neutropenia (moderate certainty) and infection (limited certainty). Convalescent plasma may be associated with thrombotic events (limited certainty) as well as bleeding events and infection in patients with hematologic cancers (moderate certainty). Inclusion of studies without a US site could potentially change the findings.

Severe COVID-19 infection may have serious consequences, especially in hospitalized patients with comorbidities. These consequences may be confused with toxicities of the interventions. Based on our analysis, approved treatments for COVID-19 should be prescribed as clinically indicated, although continued vigilance is warranted to identify rare and potentially significant toxicities that may arise in clinical practice.

PROSPERO (CRD42023467821).

Patients with hematologic diseases have experienced coronavirus disease 2019 (COVID-19) with a prolonged, progressive course. Here, we present clinical, pathological, and virological analyses of three cases of prolonged COVID-19 among patients undergoing treatment for B-cell lymphoma. These patients had all been treated with anti-CD20 antibody and bendamustine. Despite various antiviral treatments, high severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) levels persisted for >4 weeks, and two of them succumbed to COVID-19. The autopsy showed bronchopneumonia, interstitial pneumonia, alveolar hemorrhage, and fibrosis. Overlapping cytomegalovirus, fungal and/or bacterial infections were also confirmed. Sequencing of SARS-CoV-2 showed accumulation of mutations and changes in variant allele frequencies over time. NSP12 mutations V792I and M794I appeared independently in two cases as COVID-19 progressed. In vitro drug susceptibility analysis and an animal experiment using recombinant SARS-CoV-2 demonstrated that each mutation, V792 and M794I, was independently responsible for remdesivir resistance and attenuated pathogenicity. E340A, E340D, and F342INS mutations in the spike protein were found in one case, which may account for the sotrovimab resistance. Analysis of autopsy specimens indicated heterogeneous distribution of these mutations. In summary, we demonstrated temporal and spatial diversity in SARS-CoV-2 that evolved resistance to various antiviral agents in malignant lymphoma patients under immunodeficient conditions caused by certain types of immunochemotherapies. Strategies may be necessary to prevent the acquisition of drug resistance and improve outcomes, such as the selection of appropriate treatment strategies for lymphoma considering patients' immune status and the institution of early intensive antiviral therapy.