Comparative Effectiveness of Combined Favipiravir and Oseltamivir Therapy Versus Oseltamivir Monotherapy in Critically Ill Patients With Influenza Virus Infection

Synergistic Antiviral Activity of European Black Elderberry Fruit Extract and Quinine Against SARS-CoV-2 and Influenza A Virusa

BACKGROUND/OBJECTIVES

The persistent threat of emerging respiratory RNA viruses like SARS-CoV-2 and Influenza A virus (IAV) necessitates the continuous development of effective, safe, broadly acting, and generally accessible antiviral agents. Current treatments often face limitations such as early administration requirements, resistance development, and limited global access. Natural products, like European black elderberry (Sambucus nigra L.; S. nigra) fruit extract and quinine, have been used historically against viral infections. In this study, we investigated the antiviral efficacy of a standardized black elderberry fruit extract containing 3.2% anthocyanins (EC 3.2) and, as a second natural antiviral product, quinine, against IAV and SARS-CoV-2 in vitro.

METHODS

Madin-Darby Canine Kidney II (MDCKII) cells were infected with IAV PR-8, while human Calu-3 lung epithelial cells were infected with Wuhan-type SARS-CoV-2. Cells were treated with varying concentrations of EC 3.2 and quinine either as mono- or combinational therapy. Viral replication was assessed using quantitative RT-PCR, and cell viability was evaluated using WST-1 assays.

RESULTS

Our results demonstrate, for the first time, that both EC 3.2 and quinine individually inhibited IAV replication in a dose-dependent manner, with IC50 values of approximately 1:400 for EC 3.2 and 250 nM for quinine. Most importantly, the combinational treatment exhibited a strong synergistic antiviral effect, as confirmed by the Bliss independence model (synergy scores of 14.7 for IAV, and 27.8 for SARS-CoV-2), without affecting cell viability.

CONCLUSIONS

These findings suggest that the combined use of black elderberry extract and quinine might serve as an effective antiviral strategy against IAV and SARS-CoV-2, particularly since the synergistic effect allows for lower doses of each product while retaining therapeutic efficacy. In summary, this combinational in vitro approach, when expanded to other respiratory RNA viruses and confirmed in clinical studies, has the potential to open a promising avenue for pandemic preparedness.

Antiviral strategies against influenza virus: an update on approved and innovative therapeutic approaches

Influenza viruses still represent a great concern for Public Health by causing yearly seasonal epidemics and occasionally worldwide pandemics. Moreover, spillover events at the animal-human interface are becoming more frequent nowadays, also involving animal species not previously found as reservoirs. To restrict the effects of influenza virus epidemics, especially in at-risk population, and to prepare a drug arsenal for possible future pandemics, researchers worldwide have been working on the development of antiviral strategies since the 80's of the last century. One of the main obstacles is the considerable genomic variability of influenza viruses, which constantly poses the issues of drug-resistance emergence and immune evasion. This review summarizes the approved therapeutics for clinical management of influenza, promising new anti-flu compounds and monoclonal antibodies currently undergoing clinical evaluation, and molecules with efficacy against influenza virus in preclinical studies. Moreover, we discuss some innovative anti-influenza therapeutic approaches such as combination therapies and targeted protein degradation. Given the limited number of drugs approved for influenza treatment, there is a still strong need for novel potent anti-influenza drugs endowed with a high barrier to drug resistance and broad-spectrum activity against influenza viruses of animal origin that may be responsible of future large outbreaks and pandemics.

Effect of Metagenomic Next-Generation Sequencing on Clinical Outcomes of Patients With Severe Community-Acquired Pneumonia in the ICU: A Multicenter, Randomized Controlled Trial

BACKGROUND

Metagenomic next-generation sequencing (mNGS) was previously established as a method that can increase the pathogen identification rate in patients with severe community-acquired pneumonia (SCAP).

RESEARCH QUESTION

What is the impact on clinical outcomes of mNGS of BAL fluid (BALF) in patients with SCAP in the ICU?

STUDY DESIGN AND METHODS

A multicenter randomized controlled open-label clinical trial was conducted in 10 ICUs. Patients were randomized in a 1:1 ratio to undergo BALF assessment with conventional microbiological tests (CMTs) only (ie, the CMT group) or BALF assessment with both mNGS and CMTs (ie, the mNGS group). The primary outcome was the time to clinical improvement, defined as the time from randomization to either an improvement of two points on a six-category ordinal scale or discharge from the ICU, whichever occurred first.

RESULTS

A total of 349 patients were randomized to treatment between January 1, 2021, and November 18, 2022; 170 were assigned to the CMT group and 179 to the mNGS group. In the intention-to-treat analysis, the time to clinical improvement was better in the mNGS group than in the CMT group (10 days vs 13 days; difference, -2.0 days; 95% CI, -3.0 to 0.0 days). Similar results were obtained in the per-protocol analysis. The proportion of patients with clinical improvement within 14 days was significantly higher in the mNGS group (62.0%) than in the CMT group (46.5%). There was no significant difference in other secondary outcomes.

INTERPRETATION

We found that compared with the use of CMTs alone, mNGS combined with CMTs reduced the time to clinical improvement for patients with SCAP.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR; www.chictr.org.cn/index.html; ChiCTR2000037894.

Single-dose suraxavir marboxil for acute uncomplicated influenza in adults and adolescents: a multicenter, randomized, double-blind, placebo-controlled phase 3 trial

Suraxavir marboxil (GP681) is an antiviral drug inhibiting the polymerase acidic protein (PA) of RNA polymerase, of influenza. It has shown therapeutic activity against influenza A and B virus infections in preclinical studies. In this multicenter randomized, double-blind, placebo-controlled, phase 3 trial, we aimed to investigate the efficacy and safety of single-dose suraxavir marboxil (40-mg oral dose) in otherwise healthy outpatients aged 5-65 years with uncomplicated influenza unaccompanied by severe issues. From 28 July 2022 to 31 October 2023, 591 outpatients aged 5-65 years with uncomplicated influenza underwent randomization in 46 research centers in China and were randomly assigned in a 2:1 ratio to receive suraxavir marboxil (40 mg) or placebo within 2 days of symptom onset. The primary outcome was time to alleviation of influenza symptoms (TTAS) (from the start of treatment until body temperature returned to 37.2 °C or less and all seven influenza symptoms (cough, sore throat, headache, nasal congestion, feverishness or chills, muscle or joint pain, and fatigue) resolved for at least 21.5 h) within 15 days by treatment. The secondary endpoints included virological indicators, system and respiratory symptoms, PA variant mutation and adverse events. The median TTAS was significantly shorter in the group that received suraxavir marboxil compared to the placebo group (42.0 h versus 63.0 h, P = 0.002). Suraxavir marboxil was associated with more rapid decrease in viral load from baseline than placebo by 1 day after administration, with a mean change of -2.2 ± 1.3 compared to -1.3 ± 1.7 log10 copies per ml (P < 0.001) in the placebo group. Adverse events were reported in 28.4% (112 of 395) of suraxavir marboxil recipients and 23.3% (45 of 193) of placebo recipients, most of which were mild or moderate. The incidences of PA variants with the I38T mutation in the H1N1pdm and H3N2 subtypes were 0.7% (1 of 138) and 0.9% (2 of 213), respectively. Low acquired drug resistance was observed. In this trial, timely single-dose suraxavir marboxil was effective in shortening TTAS and reducing the influenza viral load in patients aged 5-65 years with uncomplicated influenza safely. ClinicalTrials.gov registration: NCT05474755 .

[Effectiveness of riamilovir in preventing respiratory viral infection among young people from organized collectives]

AIM

To evaluate the efficacy of the antiviral drug riamilovir (trade name - «Triazavirin®») for the prevention of SARS-CoV-2 infection (COVID-19) and other acute respiratory viral infections in young people from organized groups.

MATERIALS AND METHODS

The study involved 386 individuals aged 18-22 years: 199 received riamilovir at a daily dose of 250 mg for 15 days, while 187 did not receive prophylactic drugs. For 30 days, disease occurrence was monitored among volunteers. In case of illness, the duration, severity of clinical manifestations, complications, and pathogen elimination dynamics were assessed via PCR from nasopharyngeal and oropharyngeal swabs.

RESULTS

During riamilovir administration, a statistically significant reduction in cases of acute respiratory viral infections of non-coronavirus etiology was observed, with no COVID-19 cases reported, confirmed by the absence of SARS-CoV-2 RNA in this group. The shortest duration of acute respiratory viral infections was noted in patients taking the prophylactic drug.

CONCLUSION

Riamilovir (trade name - «Triazavirin®») showed statistically significant prophylactic efficacy during its administration in an organized group. Its use decreased the frequency of detection of viral pathogens and resulted in milder acute respiratory disease, likely due to reduced viral load in individuals.

Influenza B virus: Target and acting mechanism of antiviral drugs

The influenza B virus is one of the causes of seasonal influenza, which has a long history of existence in various populations. Adolescents, children, pregnant women, the elderly, as well as patients with major diseases such as high blood pressure, diabetes, and cancer, and those with low immunity are more susceptible to infection by the influenza virus. During the influenza seasons, the influenza B virus can cause significant harm and economic burden. At present, neuraminidase inhibitors, hemagglutinin inhibitors and RNA polymerase inhibitors are the main antiviral drugs that are used in the clinical treatment of influenza B. Due to the repeated use of antiviral drugs in recent years, the emergence of resistant strains of the influenza virus exacerbated. By combining anti-viral drugs with different mechanisms of action or using a combination of traditional Chinese medicine and chemical drugs, the problem of reduced drug sensitivity can be improved. This article introduces the drug targets of the influenza B virus and the mechanism of virus resistance. It also emphasizes the clinically used antiviral drugs and their mechanisms of action, thereby providing a reference basis for the development of new anti-influenza drugs.

Dayuan Yin alleviates symptoms of HCoV-229E-induced pneumonia and modulates the Ras/Raf1/MEK/ERK pathway

Viral pneumonia is characterized by inflammation in the lungs triggered by respiratory viruses. Dayuan Yin (DYY), a traditional Chinese medicine formula known for treating infectious diseases, is hypothesized to offer therapeutic benefits in treating viral pneumonia, although its specific molecular impacts remain understudied. This study aimed to evaluate the therapeutic effects of DYY in mitigating HCoV-229E virus-induced pneumonia in mice. This study employed an HCoV-229E virus-infected mouse model to investigate the therapeutic potential and underlying molecular mechanisms of DYY on virus-induced pneumonia. The respiratory function and organ indices post-treatment were assessed. Lung tissue and tracheal lesions were evaluated via immunohistochemistry. Spleen immune cell composition was analyzed using flow cytometry. Inflammatory cytokines and viral loads were quantified using hypersensitive multiplex electrochemiluminescence method and PCR analysis, respectively. The expression levels of MAS1, Ras, Raf1, MEK1/2, and ERK1/2 in lung tissues were determined through western blot analysis. DYY significantly improved respiratory function, and reduced organ pathology in infected mice. It effectively decreased viral loads and inflammatory cytokines such as IL-6, IL-1β, and TNF-α in lung tissues. Enhancements in immune response were evidenced by increased CD4/CD8 ratios in the spleen. DYY also notably upregulated MAS1 protein levels and suppressed the activation of the Ras/Raf1/MEK/ERK signaling pathway. DYY enhanced respiratory function and exerted significant antiviral and immunomodulatory effects in mice infected with the HCoV-229E virus, primarily by modulating MAS1 expression and inhibiting the Ras/Raf1/MEK/ERK pathway.

Convenient screening of the reproductive toxicity of favipiravir and antiviral drugs in Caenorhabditis elegans

Reproductive toxicity is one of the major concerns in drug development. Thus, we have developed its screening system using Caenorhabditis elegans, which has a life cycle of three days and similar coding genes as humans. Antiviral nucleoside analogs used for acute infections are known to cause reproductive toxicity, contraindicated for pregnant women, and are used for comparing their reproductive toxicity in C. elegans and experimental animals. None of the drug treatments affected the number of offspring and the concentrations without toxicity to nematodes were consistent with no cytotoxicity or toxicity in experimental animals or humans. Favipiravir, ribavirin, molnupiravir (NHC), acyclovir, ganciclovir, zidovudine, and thalidomide significantly increased the incidence of arrested embryos but amenamevir, letermovir, and guanosine did not. RNA-dependent RNA polymerase (RdRp) inhibitors, in the order of favipiravir, ribavirin, and NHC increased the incidence of arrested embryos, possibly due to the specificity of favipiravir for RdRp and less cytotoxicity. RdRp inhibitors would impair RNA interference through RdRp expressed by telomerase reverse transcriptase during embryogenesis and cause embryo-fetal toxicity. The incidence of arrested embryos may be affected by differences in the substrate specificity of DNA polymerases and metabolism between C. elegans, animals, and humans. The concordance between the results of the screening system for reproductive toxicity of antivirals in C. elegans and those in experimental animals based on the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use, reproductive toxicology confirms its appropriateness as a screening system for reproductive toxicity. Favipiravir and zidovudine were the least toxic to C. e legans among the antiviral drugs examined.

Long-term radiological and pulmonary function abnormalities at 3 years after COVID-19 hospitalisation: a longitudinal cohort study

BACKGROUND

This study aimed to evaluate the longitudinal progression of residual lung abnormalities (ground-glass opacities, reticulation and fibrotic-like changes) and pulmonary function at 3 years following coronavirus disease 2019 (COVID-19).

METHODS

This prospective, longitudinal cohort study enrolled COVID-19 survivors who exhibited residual lung abnormalities upon discharge from two hospitals. Follow-up assessments were conducted at 6 months, 12 months, 2 years and 3 years post-discharge, and included pulmonary function tests, 6-min walk distance (6MWD), chest computed tomography (CT) scans and symptom questionnaires. Non-COVID-19 controls were retrospectively recruited for comparative analysis.

RESULTS

728 COVID-19 survivors and 792 controls were included. From 6 months to 3 years, there was a gradual improvement in reduced diffusing capacity of the lung for carbon monoxide (D LCO <80% predicted: 49% versus 38%; p=0.001), 6MWD (496 versus 510 m; p=0.002) and residual lung abnormalities (46% versus 36%; p<0.001), regardless of disease severity. Patients with residual lung abnormalities at 3 years more commonly had respiratory symptoms (32% versus 16%; p<0.001), lower 6MWD (494 versus 510 m; p=0.003) and abnormal D LCO (57% versus 27%; p<0.001) compared with those with complete resolution. Compared with controls, the proportions of D LCO impairment (38% versus 17%; p<0.001) and respiratory symptoms (23% versus 2.2%; p<0.001) were significantly higher in the matched COVID-19 survivors at the 3-year follow-up.

CONCLUSIONS

Most patients exhibited improvement in radiological abnormalities and pulmonary function over time following COVID-19. However, more than a third continued to have persistent lung abnormalities at the 3-year mark, which were associated with respiratory symptoms and reduced diffusion capacity.

Treating influenza with neuraminidase inhibitors: an update of the literature

INTRODUCTION

Influenza affects individuals of all ages and poses a significant threat during pandemics, epidemics, and sporadic outbreaks. Neuraminidase inhibitors (NAIs) are currently the first choice in the treatment and prevention of influenza, but their use can be hindered by viral resistance.

AREAS COVERED

This review summarizes current NAIs pharmacological profiles, their current place in therapy, and the mechanisms of viral resistance and outlines possible new indications, ways of administration, and novel candidate NAIs compounds.

EXPERT OPINION

NAIs represent a versatile group of compounds with diverse administration methods and pharmacokinetics. While the prevalence of influenza virus resistance to NAIs remains low, there is heightened vigilance due to the pandemic potential of influenza. Several novel NAIs and derivatives are currently under assessment at various stages of development for the treatment and prevention of influenza.

Retracted and republished from: "The current state of research on influenza antiviral drug development: drugs in clinical trial and licensed drugs"

Influenza viruses (IVs) threaten global human health due to the high morbidity, infection, and mortality rates. Currently, the influenza drugs recommended by the Food and Drug Administration are oseltamivir, zanamivir, peramivir, and baloxavir marboxil. These recommended antivirals are currently effective for major subtypes of IVs as the compounds target conserved domains in neuraminidase or polymerase acidic (PA) protein. However, this trend may gradually change due to the selection of antiviral drugs and the natural evolution of IVs. Therefore, there is an urgent need to develop drugs related to the treatment of influenza to deal with the next pandemic. Here, we summarized the cutting-edge research in mechanism of action, inhibitory activity, and clinical efficacy of drugs that have been approved and drugs that are still in clinical trials for influenza treatment. We hope this review will provide up-to-date and comprehensive information on influenza antivirals and generate hypotheses for screens and development of new broad-spectrum influenza drugs in the near future.

Initial therapeutic anticoagulation with rivaroxaban compared to prophylactic therapy with heparins in moderate to severe COVID-19: results of the COVID-PREVENT randomized controlled trial

BACKGROUND

COVID-19 is associated with a prothrombotic state. Current guidelines recommend prophylactic anticoagulation upon hospitalization.

METHODS

COVID-PREVENT, an open-label, multicenter, randomized, clinical trial enrolled patients (≥ 18 years) with moderate to severe COVID-19 and age-adjusted D-dimers > 1.5 upper limit of normal (ULN). The participants were randomly assigned (1:1) to receive either therapeutic anticoagulation with rivaroxaban 20 mg once daily or thromboprophylaxis with a heparin (SOC) for at least 7 days followed by prophylactic anticoagulation with rivaroxaban 10 mg once daily for 28 days or no thromboprophylaxis. The primary efficacy outcome was the D-dimer level and the co-primary efficacy outcome the 7-category ordinal COVID-19 scale by WHO at 7 days post randomization. The secondary outcome was time to the composite event of either venous or arterial thromboembolism, new myocardial infarction, non-hemorrhagic stroke, all-cause death or progression to intubation and invasive ventilation up to 35 days post randomization.

RESULTS

The primary efficacy outcome D-dimer at 7 days was not different between patients assigned to therapeutic (n = 55) or prophylactic anticoagulation (n = 56) (1.21 mg/L [0.79, 1.86] vs 1.27 mg/L [0.79, 2.04], p = 0.78). In the whole study population D-dimer was significantly lower at 7 days compared to baseline (1.05 mg/L [0.75, 1.48] vs 1.57 mg/L [1.13, 2.19], p < 0.0001). Therapy with rivaroxaban compared to SOC was not associated an improvement on the WHO 7-category ordinal scale at 7 days (p = 0.085). Rivaroxaban improved the clinical outcome measured by the score in patients with a higher baseline D-dimer  > 2.0 ULN (exploratory analysis; 0.632 [0.516, 0.748], p = 0.026). The secondary endpoint occurred in 6 patients (10.9%) in the rivaroxaban group and in 12 (21.4%) in the SOC group (time-to-first occurrence of the components of the secondary outcome: HR 0.5; 95% CI 0.15-1.67; p = 0.264). There was no difference in fatal or non-fatal major or clinically relevant non-major bleeding between the groups.

CONCLUSIONS

Therapeutic anticoagulation with rivaroxaban compared to prophylactic anticoagulation with a heparin did not improve surrogates of clinical outcome in patients with moderate to severe COVID-19. Whether initial rivaroxaban at therapeutic doses might be superior to thromboprophylaxis in patients with COVID-19 and a high risk as defined by D-dimer  > 2 ULN needs confirmation in further studies.

Respiratory virus infections after allogeneic stem cell transplantation: Current understanding, knowledge gaps, and recent advances

Before the COVID-19 pandemic, common community-acquired seasonal respiratory viruses (CARVs) were a significant threat to the health and well-being of allogeneic hematopoietic cell transplant (allo-HCT) recipients, often resulting in severe illness and even death. The pandemic has further highlighted the significant risk that immunosuppressed patients, including allo-HCT recipients, face when infected with SARS-CoV-2. As preventive transmission measures are relaxed and CARVs circulate again among the community, including in allo-HSCT recipients, it is crucial to understand the current state of knowledge, gaps, and recent advances regarding CARV infection in allo-HCT recipients. Urgent research is needed to identify seasonal respiratory viruses as potential drivers for future pandemics.

The current state of research on influenza antiviral drug development: drugs in clinical trial and licensed drugs

Influenza viruses (IVs) threaten global human health due to the high morbidity, infection, and mortality rates. Currently, the influenza drugs recommended by the FDA are oseltamivir, zanamivir, peramivir, and baloxavir marboxil. Notably, owing to the high variability of IVs, no drug exists that can effectively treat all types and subtypes of IVs. Moreover, the current trend of drug resistance is likely to continue as the viral genome is constantly mutating. Therefore, there is an urgent need to develop drugs related to the treatment of influenza to deal with the next pandemic. Here, we summarized the cutting-edge research in mechanism of action, inhibitory activity, and clinical efficacy of drugs that have been approved and drugs that are still in clinical trials for influenza treatment. We hope this review will provide up-to-date and comprehensive information on influenza antivirals and generate hypotheses for screens and development of new broad-spectrum influenza drugs in the near future.

The combined effect of oseltamivir and favipiravir on influenza a virus evolution in patients hospitalized with severe influenza

Our previous study shows favipiravir and oseltamivir combination therapy may accelerate clinical recovery compared to oseltamivir monotherapy in severe influenza, but its effect on virological evolution and resistance mutation against oseltamivir is still unknown. In this study, we collected longitudinal respiratory samples from influenza patients who underwent combination therapy and applied them to next generation sequencing of the whole genome of the influenza A virus (IAV). We also included a cohort untreated with any antivirals to serve as the control. In total, 62 samples from 19 patients treated with combination therapy and 20 samples from 20 patients untreated were successfully sequenced. The nucleotide diversity in the whole genome of IAV in the combination group showed no difference compared to that in the control group (P > 0.05). Moreover, we observed 174 kinds of nonsynonymous nucleotide substitutions in patients with combination therapy, mostly in NA (n = 44) and HA (n = 43). Of them, the G→A transition was the dominant variant type (27%) and 46/174 (26%) was reported to have biological effects, such as increased pathogenicity and polymerase activity. Among the 29 mutations conferring reduction in oseltamivir sensitivity we investigated, H275Y was the only mutation detected in the 4 samples from 1 of 19 patients and demonstrated increasing frequency during the treatment. Mutations conferring favipiravir resistance were not observed. Our studies showed combination therapy of favipiravir and oseltamivir has little effect on virus nucleotide diversity, nor prevents the increase of oseltamivir-resistant variants.

T-705-Derived Prodrugs Show High Antiviral Efficacies against a Broad Range of Influenza A Viruses with Synergistic Effects When Combined with Oseltamivir

Emerging influenza A viruses (IAV) bear the potential to cause pandemics with unpredictable consequences for global human health. In particular, the WHO has declared avian H5 and H7 subtypes as high-risk candidates, and continuous surveillance of these viruses as well as the development of novel, broadly acting antivirals, are key for pandemic preparedness. In this study, we sought to design T-705 (Favipiravir) related inhibitors that target the RNA-dependent RNA polymerase and evaluate their antiviral efficacies against a broad range of IAVs. Therefore, we synthesized a library of derivatives of T-705 ribonucleoside analogues (called T-1106 pronucleotides) and tested their ability to inhibit both seasonal and highly pathogenic avian influenza viruses in vitro. We further showed that diphosphate (DP) prodrugs of T-1106 are potent inhibitors of H1N1, H3N2, H5N1, and H7N9 IAV replication. Importantly, in comparison to T-705, these DP derivatives achieved 5- to 10-fold higher antiviral activity and were non-cytotoxic at the therapeutically active concentrations. Moreover, our lead DP prodrug candidate showed drug synergy with the neuraminidase inhibitor oseltamivir, thus opening up another avenue for combinational antiviral therapy against IAV infections. Our findings may serve as a basis for further pre-clinical development of T-1106 prodrugs as an effective countermeasure against emerging IAVs with pandemic potential.

Favipiravir in patients hospitalised with COVID-19 (PIONEER trial): a multicentre, open-label, phase 3, randomised controlled trial of early intervention versus standard care

BACKGROUND

COVID-19 has overwhelmed health services globally. Oral antiviral therapies are licensed worldwide, but indications and efficacy rates vary. We aimed to evaluate the safety and efficacy of oral favipiravir in patients hospitalised with COVID-19.

METHODS

We conducted a multicentre, open-label, randomised controlled trial of oral favipiravir in adult patients who were newly admitted to hospital with proven or suspected COVID-19 across five sites in the UK (n=2), Brazil (n=2) and Mexico (n=1). Using a permuted block design, eligible and consenting participants were randomly assigned (1:1) to receive oral favipiravir (1800 mg twice daily for 1 day; 800 mg twice daily for 9 days) plus standard care, or standard care alone. All caregivers and patients were aware of allocation and those analysing data were aware of the treatment groups. The prespecified primary outcome was the time from randomisation to recovery, censored at 28 days, which was assessed using an intention-to-treat approach. Post-hoc analyses were used to assess the efficacy of favipiravir in patients aged younger than 60 years, and in patients aged 60 years and older. The trial was registered with clinicaltrials.gov, NCT04373733.

FINDINGS

Between May 5, 2020 and May 26, 2021, we assessed 503 patients for eligibility, of whom 499 were randomly assigned to favipiravir and standard care (n=251) or standard care alone (n=248). There was no significant difference between those who received favipiravir and standard care, relative to those who received standard care alone in time to recovery in the overall study population (hazard ratio [HR] 1·06 [95% CI 0·89-1·27]; n=499; p=0·52). Post-hoc analyses showed a faster rate of recovery in patients younger than 60 years who received favipiravir and standard care versus those who had standard care alone (HR 1·35 [1·06-1·72]; n=247; p=0·01). 36 serious adverse events were observed in 27 (11%) of 251 patients administered favipiravir and standard care, and 33 events were observed in 27 (11%) of 248 patients receiving standard care alone, with infectious, respiratory, and cardiovascular events being the most numerous. There was no significant between-group difference in serious adverse events per patient (p=0·87).

INTERPRETATION

Favipiravir does not improve clinical outcomes in all patients admitted to hospital with COVID-19, however, patients younger than 60 years might have a beneficial clinical response. The indiscriminate use of favipiravir globally should be cautioned, and further high-quality studies of antiviral agents, and their potential treatment combinations, are warranted in COVID-19.

FUNDING

LifeArc and CW+.

Antiviral Approaches against Influenza Virus

Preventing and controlling influenza virus infection remains a global public health challenge, as it causes seasonal epidemics to unexpected pandemics. These infections are responsible for high morbidity, mortality, and substantial economic impact. Vaccines are the prophylaxis mainstay in the fight against influenza. However, vaccination fails to confer complete protection due to inadequate vaccination coverages, vaccine shortages, and mismatches with circulating strains. Antivirals represent an important prophylactic and therapeutic measure to reduce influenza-associated morbidity and mortality, particularly in high-risk populations. Here, we review current FDA-approved influenza antivirals with their mechanisms of action, and different viral- and host-directed influenza antiviral approaches, including immunomodulatory interventions in clinical development. Furthermore, we also illustrate the potential utility of machine learning in developing next-generation antivirals against influenza.

Potential Anti-SARS-CoV-2 Prodrugs Activated by Phosphorylation and Their Role in the Aged Population

The COVID-19 pandemic has flared across every part of the globe and affected populations from different age groups differently. People aged from 40 to 80 years or older are at an increased risk of morbidity and mortality due to COVID-19. Therefore, there is an urgent requirement to develop therapeutics to decrease the risk of the disease in the aged population. Over the last few years, several prodrugs have demonstrated significant anti-SARS-CoV-2 effects in in vitro assays, animal models, and medical practice. Prodrugs are used to enhance drug delivery by improving pharmacokinetic parameters, decreasing toxicity, and attaining site specificity. This article discusses recently explored prodrugs such as remdesivir, molnupiravir, favipiravir, and 2-deoxy-D-glucose (2-DG) and their implications in the aged population, as well as investigating recent clinical trials.

Influenza antivirals and their role in pandemic preparedness

Effective antivirals provide crucial benefits during the early phase of an influenza pandemic, when vaccines are still being developed and manufactured. Currently, two classes of viral protein-targeting drugs, neuraminidase inhibitors and polymerase inhibitors, are approved for influenza treatment and post-exposure prophylaxis. Resistance to both classes has been documented, highlighting the need to develop novel antiviral options that may include both viral and host-targeted inhibitors. Such efforts will form the basis of management of seasonal influenza infections and of strategic planning for future influenza pandemics. This review focuses on the two classes of approved antivirals, their drawbacks, and ongoing work to characterize novel agents or combination therapy approaches to address these shortcomings. The importance of these topics in the ongoing process of influenza pandemic planning is also discussed.

Influenza Treatment: Limitations of Antiviral Therapy and Advantages of Drug Combination Therapy

Influenza infection is serious and debilitating for humans and animals. The influenza virus undergoes incessant mutation, segment recombination, and genome reassortment. As a result, new epidemics and pandemics are expected to emerge, making the elimination challenging of the disease. Antiviral therapy has been used for the treatment of influenza since the development of amantadine in the 1960s; however, its use is hampered by the emergence of novel strains and the development of drug resistance. Thus, combinational therapy with two or more antivirals or immunomodulators with different modes of action is the optimal strategy for the effective treatment of influenza infection. In this review, we describe current options for combination therapy, their performance, and constraints imposed by resistance, calling attention to the advantages of combination therapy against severe influenza infections. We also discuss the challenges of influenza therapy and the limitations of approved antiviral drugs.

Favipiravir-Tautomeric and Complexation Properties in Solution

The tautomeric properties of favipiravir were investigated experimentally for the first time by using molecular spectroscopy (UV-Vis absorption, fluorescence and NMR), as well as DFT quantum-chemical calculations. According to the obtained results, the enol tautomer is substantially more stable in most of the organic solvents. In the presence of water, a keto form appears to be favored due to the specific solute-solvent interactions. Upon the addition of alkaline-earth-metal ions, deprotonation and complexation occurred simultaneously, giving the formation of 2 : 1 ligand : metal complexes. According to the theoretical simulations, the metal ion is captured between the carbonyl groups as a result of the size-fit effect.

Combination therapy with nirmatrelvir and molnupiravir improves the survival of SARS-CoV-2 infected mice

As the SARS-CoV-2 pandemic remains uncontrolled owing to the continuous emergence of variants of concern, there is an immediate need to implement the most effective antiviral treatment strategies, especially for risk groups. Here, we evaluated the therapeutic potency of nirmatrelvir, remdesivir and molnupiravir, and their combinations in SARS-CoV-2 infected K18-hACE2 transgenic mice. Systemic treatment of mice with each drug (20 mg/kg) resulted in slightly enhanced antiviral efficacy and yielded an increased life expectancy of only about 20-40% survival. However, combination therapy with nirmatrelvir (20 mg/kg) and molnupiravir (20 mg/kg) in lethally infected mice showed profound inhibition of SARS-CoV-2 replication in both the lung and brain and synergistically improved survival rates up to 80% compared to those with nirmatrelvir (36%, P < 0.001) and molnupiravir (43%, P < 0.001) administered alone. This combination therapy effectively reduced clinical severity score, virus-induced tissue damage, and viral distribution compared to those in animals treated with these monotherapies. Furthermore, all these assessments associated with this combination were also significantly higher than that of mice receiving remdesivir monotherapy (P < 0.001) and the nirmatrelvir (20 mg/kg) and remdesivir (20 mg/kg) combination (P < 0.001), underscored the clinical significance of this combination. By contrast, the nirmatrelvir and remdesivir combination showed less antiviral efficacy, with lower survival compared to nirmatrelvir monotherapy due to the insufficient plasma exposure of the remdesivir, demonstrating the inefficient therapeutic effect of this combination in the mouse model. The combination therapy with nirmatrelvir and molnupiravir contributes to alleviated morbidity and mortality, which can serve as a basis for the design of clinical studies of this combination in the treatment of COVID-19 patients.

Potential Treatment of COVID-19 with Traditional Chinese Medicine: What Herbs Can Help Win the Battle with SARS-CoV-2?

Traditional Chinese medicine (TCM) has been successfully applied worldwide in the treatment of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the pharmacological mechanisms underlying this success remain unclear. Hence, the aim of this review is to combine pharmacological assays based on the theory of TCM in order to elucidate the potential signaling pathways, targets, active compounds, and formulas of herbs that are involved in the TCM treatment of COVID-19, which exhibits combatting viral infections, immune regulation, and amelioration of lung injury and fibrosis. Extensive reports on target screening are elucidated using virtual prediction via docking analysis or network pharmacology based on existing data. The results of these reports indicate that an intricate regulatory mechanism is involved in the pathogenesis of COVID-19. Therefore, more pharmacological research on the natural herbs used in TCM should be conducted in order to determine the association between TCM and COVID-19 and account for the observed therapeutic effects of TCM against COVID-19.

Efficacy of colchicine in patients with moderate COVID-19: A double-blinded, randomized, placebo-controlled trial

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may cause severe life-threatening diseases called acute respiratory distress syndrome (ARDS) owing to cytokine storms. The mortality rate of COVID-19-related ARDS is as high as 40% to 50%. However, effective treatment for the extensive release of acute inflammatory mediators induced by hyperactive and inappropriate immune responses is very limited. Many anti-inflammatory drugs with variable efficacies have been investigated. Colchicine inhibits interleukin 1 beta (IL-1β) and its subsequent inflammatory cascade by primarily blocking pyrin and nucleotide-binding domain leucine-rich repeat and pyrin domain containing receptor 3 (NLRP3) activation. Therefore, this cheap, widely available, oral drug might provide an added benefit in combating the cytokine storm in COVID-19. Here, we sought to determine whether adding colchicine to other standards of care could be beneficial for moderate COVID-19 pneumonia in terms of the requirement for advanced respiratory support and mortality.

METHODS AND FINDINGS

This blinded placebo-controlled drug trial was conducted at the Dhaka Medical College Hospital, Dhaka, Bangladesh. A total of 300 patients with moderate COVID-19 based on a positive RT-PCR result were enrolled based on strict selection criteria from June 2020 to November 2020. Patients were randomly assigned to either treatment group in a 1:1 ratio. Patients were administered 1.2 mg of colchicine on day 1 followed by daily treatment with 0.6 mg of colchicine for 13 days or placebo along with the standard of care. The primary outcome was the time to clinical deterioration from randomization to two or more points on a seven-category ordinal scale within the 14 days post-randomization. Clinical outcomes were also recorded on day 28. The primary endpoint was met by 9 (6.2%) patients in the placebo group and 4 (2.7%) patients in the colchicine group (P = 0.171), which corresponds to a hazard ratio (95% CI) of 0.44 (0.13-1.43). Additional analysis of the outcomes on day 28 revealed significantly lower clinical deterioration (defined as a decrease by two or more points) in the colchicine group, with a hazard ratio [95%CI] of 0.29 [0.098-0.917], (P = 0.035). Despite a 56% reduction in the need for mechanical ventilation and death with colchicine treatment on day 14, the reduction was not statistically significant. On day 28, colchicine significantly reduced clinical deterioration measured as the need for mechanical ventilation and all-cause mortality.

CONCLUSION

Colchicine was not found to have a significant beneficial effect on reducing mortality and the need for mechanical ventilation. However, a delayed beneficial effect was observed. Therefore, further studies should be conducted to evaluate the late benefits of colchicine.

CLINICAL TRIAL REGISTRATION

Clinical trial registration no: ClinicalTrials.gov Identifier: NCT04527562 https://www.google.com/search?client=firefox-b-d&q=NCT04527562.

Favipiravir Treatment of Uncomplicated Influenza in Adults: Results of Two Phase 3, Randomized, Double-Blind, Placebo-Controlled Trials

BACKGROUND

We conducted double-blind, placebo-controlled trials assessing the efficacy and tolerability of favipiravir in acute influenza.

METHODS

Otherwise healthy adults with influenza-like symptoms and fever of ≤48 hours were randomized to favipiravir (1800 mg twice daily [BID] on day 1, 800 mg BID on days 2-5) or placebo tablets (1:1 in US316; 3:1 in US317). The primary efficacy endpoint was the time to illness alleviation when 6 influenza symptoms were self-rated as absent or mild and fever was absent in the intention-to-treat, influenza-infected participants.

RESULTS

In US316 (301 favipiravir, 322 placebo), favipiravir was associated with a 14.4-hour reduction (median, 84.2 vs 98.6 hours; P = .004) in time to illness alleviation vs placebo. In US317 (526 favipiravir, 169 placebo), favipiravir did not significantly reduce time to alleviation (median, 77.8 vs 83.9 hours). In both trials favipiravir was associated with reduced viral titers, RNA load area under the curve over days 1-5, and median times to cessation of virus detection (P < .001). Aside from asymptomatic hyperuricemia, no important differences in adverse events were found.

CONCLUSIONS

This favipiravir dosing regimen demonstrated significant antiviral efficacy but inconsistent illness alleviation in uncomplicated influenza. Studies of higher doses and antiviral combinations for treating serious influenza and other RNA viral infections are warranted. Clinical Trials Registration. NCT02026349; NCT02008344.

Clinical significance and role of coinfections with respiratory pathogens among individuals with confirmed severe acute respiratory syndrome coronavirus-2 infection

Introduction

This study aimed to determine the prevalence, viral profile, and clinical features of coinfections with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and other respiratory viruses.

Methods

Nasopharyngeal samples and clinical data of 221 hospitalized patients and 21 outpatients were collected and analyzed. Real-time reverse transcription-polymerase chain reaction was used to detect SARS-CoV-2, influenza virus, respiratory syncytial virus (RSV), human metapneumovirus (HMPV), parainfluenza virus (PIV) 1,2,3, rhinovirus (RV), adenovirus (AdV), bocaviruses (BoV), and seasonal coronaviruses (OC43, 229E, NL63, and HKU1). Viral load was determined by capillary electrophoresis.

Results

From November 2020 to mid-March 2022, 242 SARS-CoV-2 positive patients were tested for seasonal respiratory viruses, and 24 (9.9%) cases of coinfections were detected. The distribution of viruses involved in cases of coinfections were as follows: HMPV (n = 6; 25%), RSV (n = 4;16.7%), AdV (n = 4; 16.7%), BoV (n = 4; 16.7%), PIV3 (n = 2; 8.3%), influenza A (H3N2; n = 2; 8.3%), RV (n = 1; 4.62%), and RV+BoV (n = 1; 4.62%). The proportion of detected coinfections with SARS-CoV-2 was highest in children aged 0-5 years (59%), followed by those >65 years (33%). In specimens with detected coinfection, the viral load of influenza was higher than that of SARS-CoV-2, and the mean viral load of SARS-CoV-2 was higher than that of the other respiratory viruses. C-reactive protein (CRP) and lymphocytes count in co-infected patients >65 years of age were on average higher than in children <16 years of age (mean CRP of 161.8 ± 133.1 mg/L; 19.7 ± 3.09% vs. mean 6.9 ± 8.9 mg/L, 0.9 ± 3.1%; p < 0.01). Patients >65 years of age co-infected with SARS-CoV-2 and other respiratory viruses had longer hospital stays than those <16 years of age (mean 9 ± 3.96 days vs. 5.44 ± 1.89 days; p = 0.025). The combination of AdV and SARS-CoV-2 is fatal for patients aged >65 years.

Conclusion

In patients aged >65 years, coinfection with SARS CoV-2 and other respiratory viruses, together with concomitant diseases, causes worsening of the clinical picture and complications, and can be fatal. Screening of patients with SARS CoV-2 for other respiratory viruses is needed to select appropriate treatments and prevent a fatal outcome of the disease.

Win ratio approach for analyzing composite time-to-event endpoint with opposite treatment effects in its components

There is an increasing interest in the use of win ratio with composite time-to-event due to its flexibility in combining component endpoints. Exploring this flexibility further, one interesting question is in assessing the impact when there is a difference in treatment effect in the component endpoints. For example, the active treatment may prolong the time to occurrence of the negative event such as death or ventilation; meanwhile, the treatment effect may also shorten the time to achieving positive events, such as recovery or improvement. Notably, this portrays a situation where the treatment effect on time to recovery is in a different direction of benefit compared to the time to ventilation or death. Under such circumstances, if a single endpoint is used, the benefit gained for other individual outcomes is not counted and is diminished. As consequence, the study may need a larger sample size to detect a significant effect of treatment. Such a scenario can be handled by win ratio in a novel way by ranking component events, which is different from the usual composite endpoint approach such as time-to-first event. To evaluate how the different directions of treatment effect on component endpoints will impact the win ratio analysis, we use a Clayton copula-based bivariate survival simulation to investigate the correlation of component time-to-event. Through simulation, we found that compared to the marginal model using single endpoints, the win ratio analysis on composite endpoint performs better, especially when the correlation between two events is weak. Then, we applied the methodology to an infectious disease progression simulated study motivated by COVID-19. The application demonstrates that the win ratio approach offers advantages in empirical power compared to the traditional Cox proportional hazard approach when there is a difference in treatment effect in the marginal events.

Real-World Effectiveness and Optimal Dosage of Favipiravir for Treatment of COVID-19: Results from a Multicenter Observational Study in Thailand

Favipiravir is a broad-spectrum oral antiviral agent that shows in vitro activity against SARS-CoV-2. Presently, data on the real-world effectiveness and optimal dosage of favipiravir for treating COVID-19 are limited. We conducted a retrospective observational study of hospitalized adult patients with COVID-19 at five tertiary care hospitals in Thailand. We reviewed patient charts to obtain all necessary data. Among 247 COVID-19 patients, 63 (23.0%) received ≥1 dose of favipiravir. Of these 63 patients, 61.9% were male with a median age of 48 years (range 22–85 years), 27.0% required an O₂ nasal cannula, 9.5% required non-invasive ventilation and/or high-flow O₂ therapy, and 6.4% required invasive mechanical ventilation and/or ECMO. The median baseline NEWS2 score was 5 (0–16). The Day-7 clinical improvement rate [95%CI] was 66.7% [53.7–78.0%] in all patients, 92.5% [75.7–99.1%] in patients who did not require O₂ supplementation, and 47.2% [0.4–64.5%] in patients who required O₂ supplementation. No life-threatening adverse events were identified. The 28-day mortality rate was 4.8%. A multivariate analysis revealed three poor prognostic factors for Day-7 clinical improvement (odds ratio (95%CI); p-value): older age (0.94 (0.89–0.99); p = 0.04), a higher baseline NEWS2 score (0.64 (0.47–0.88); p = 0.006), and a lower favipiravir loading dose (≤45 mg/kg/day) (0.04 (0.005–0.4); p = 0.006). In conclusion, our study reports the promising effectiveness of favipiravir for treating COVID-19 patients. In addition to older age and a high baseline NEWS2 score, a low loading dose of favipiravir (≤45 mg/kg/day) was also identified as a poor prognostic factor for early clinical improvement. Further studies to explore the optimal dose and the optimal timing of drug initiation for favipiravir should be performed.

Preclinical and clinical developments for combination treatment of influenza

Antiviral drugs are an important measure of control for influenza in the population, particularly for those that are severely ill or hospitalised. The neuraminidase inhibitor (NAI) class of drugs, including oseltamivir, have been the standard of care (SOC) for severe influenza illness for many years. The approval of drugs with novel mechanisms of action, such as baloxavir marboxil, is important and broadens potential treatment options for combination therapy. The use of antiviral treatments in combination for influenza is of interest; one potential benefit of this treatment strategy is that the combination of drugs with different mechanisms of action may lower the selection of resistance due to treatment. In addition, combination therapy may become an important treatment option to improve patient outcomes in those with severe illness due to influenza or those that are immunocompromised. Clinical trials increasingly evaluate drug combinations in a range of patient cohorts. Here, we summarise preclinical and clinical advances in combination therapy for the treatment of influenza with reference to immunocompromised animal models and clinical data in hospitalised patient cohorts where available. There is a wide array of drug categories in development that have also been tested in combination. Therefore, in this review, we have included polymerase inhibitors, monoclonal antibodies (mAbs), host-targeted therapies, and adjunctive therapies. Combination treatment regimens should be carefully evaluated to determine whether they provide an added benefit relative to effectiveness of monotherapy and in a variety of patient cohorts, particularly, if there is a greater chance of an adverse outcome. Safe and effective treatment of influenza is important not only for seasonal influenza infection, but also if a pandemic strain was to emerge.

Evaluation of the Clinical Effectiveness of Oseltamivir for Influenza Treatment in Children

Objective: To estimate the clinical effectiveness of oseltamivir in children with different subtypes of influenza virus infection.

Methods: A total of 998 children with acute respiratory infection were enrolled from January to March 2018, and were divided into influenza A, influenza B, influenza A + B, and non-influenza infection (IV-negative) groups. Influenza-like symptoms and duration of fever were evaluated and compared between oseltamivir-treated and non-treated groups.

Results: There were no significant differences in the reduction in total febrile period and duration of fever from the onset of therapy between the oseltamivir treated and non-treated children infected with influenza A (p = 0.6885 for total febrile period and 0.7904 for the duration of fever from the onset of treatment), influenza B (p = 0.1462 and 0.1966), influenza A + B (p = 0.5568 and 0.9320), and IV-negative (p = 0.7631 and 0.4655). The duration of fever in children received oseltamivir therapy within 48 h was not significantly shorter than that beyond 48 h (p > 0.05). Additionally, percentages and severities of influenza-like symptoms, including headache, myalgia, fatigue, bellyache, vomiting, diarrhea, sore throat, cough, and coryza were not decreased and alleviated after treatment of oseltamivir.

Conclusion: Oseltamivir treatment does not significantly shorten the duration of fever, nor does it significantly relieve influenza-like symptoms in children with infection of influenza.

Efficacy and Safety of SARS-CoV-2 Neutralizing Antibody JS016 in Hospitalized Chinese Patients with COVID-19: A Phase 2/3, Multicenter, Randomized, Open-label, Controlled Trial

Recombinant human severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) monoclonal antibody JS016 showed neutralizing and therapeutic effects in preclinical studies. The clinical efficacy and safety of the therapy needed to be evaluated. In this phase 2/3, multicenter, randomized, open-label, controlled trial, hospitalized patients with moderate or severe coronavirus disease 2019 (COVID-19) were randomly assigned in a 1:1 ratio to receive standard care or standard care plus a single intravenous infusion of JS016. The primary outcome was a six-level ordinal scale of clinical status on day 28 since randomization. Secondary outcomes include adverse events, 28-day mortality, ventilator-free days within 28 days, length of hospital stay, and negative conversion rate of SARS-CoV-2 nucleic acid on day 14. A total of 199 patients were randomized, and 197 (99 in the JS016 group and 98 in the control group) were analyzed. Most patients, 95 (96%) in the JS016 group and 97 (99%) in the control group were in the best category on day 28 since randomization. The odds ratio of being in a better clinical status was 0.31 (95% confidence interval [CI], 0.03 to 3.19; P = 0.33). Few adverse events occurred in both groups (3% in the JS016 group and 1% in the control group, respectively; P = 0.34). SARS-CoV-2 neutralizing antibody JS016 did not show clinical efficacy among hospitalized Chinese patients with moderate to severe COVID-19 disease. Further studies are needed to assess the efficacy of the neutralizing antibody to prevent disease deterioration and its benefits among groups of patients specified by disease course and severity. (This study has been registered at ClinicalTrials.gov under identifier NCT04931238.)

Characterization of the In Vitro and In Vivo Efficacy of Baloxavir Marboxil against H5 Highly Pathogenic Avian Influenza Virus Infection

Human infections caused by the H5 highly pathogenic avian influenza virus (HPAIV) sporadically threaten public health. The susceptibility of HPAIVs to baloxavir acid (BXA), a new class of inhibitors for the influenza virus cap-dependent endonuclease, has been confirmed in vitro, but it has not yet been fully characterized. Here, the efficacy of BXA against HPAIVs, including recent H5N8 variants, was assessed in vitro. The antiviral efficacy of baloxavir marboxil (BXM) in H5N1 virus-infected mice was also investigated. BXA exhibited similar in vitro activities against H5N1, H5N6, and H5N8 variants tested in comparison with seasonal and other zoonotic strains. Compared with oseltamivir phosphate (OSP), BXM monotherapy in mice infected with the H5N1 HPAIV clinical isolate, the A/Hong Kong/483/1997 strain, also caused a significant reduction in viral titers in the lungs, brains, and kidneys, thereby preventing acute lung inflammation and reducing mortality. Furthermore, compared with BXM or OSP monotherapy, combination treatments with BXM and OSP using a 48-h delayed treatment model showed a more potent effect on viral replication in the organs, accompanied by improved survival. In conclusion, BXM has a potent antiviral efficacy against H5 HPAIV infections.

Evaluation of efficacy and safety of Qiangzhu-qinggan formula as an adjunctive therapy in adult patients with severe influenza: study protocol for a randomized parallel placebo-controlled double-blind multicenter trial

Background

Influenza can fall into three categories according to severity: mild influenza, severe influenza, and critical influenza. Severe influenza can result in critical illness and sometimes death particularly in patients with comorbidities, advanced age, or pregnancy. Neuraminidase inhibitors (NAIs) are the only antiviral drugs in widespread use for influenza. However, the effectiveness of NAIs against severe influenza is uncertain. New effective drugs or regimens are therefore urgently needed. Qiangzhu-qinggan (QZQG) formula has been found to be effective against influenza virus infection during long-term application in China, which lacks support of evidence-based clinical trial till now. This study is designed to assess the efficacy and safety of QZQG formula as an adjuvant therapy in adult patients with severe influenza.

Methods

This protocol is drawn up in accordance with the SPIRIT guidelines and CONSORT Extension for Chinese herbal medicine formulas. This is a randomized, placebo-controlled, double-blind, multicenter trial. Two hundred twenty-eight adults with severe influenza are randomly assigned in a 1:1 ratio to QZQG or placebo for 7 days. All participants need to receive 1 day of screening before randomization, 7 days of intervention, and 21 days of observation after randomization. The primary outcome is the proportion of clinical improvement, defined as the proportion of patients who met the criteria of 3 points or less in the seven-category ordinal scale or 2 points or less in National Early Warning Score 2 within 7 days after randomization.

Discussion

This is the first randomized, controlled, parallel, double-blind clinical trial to evaluate the efficacy and safety of traditional Chinese herbal formula granules as an adjuvant therapy in adult patients with severe influenza. This study aims to redefine the value of traditional Chinese herbal medicines in the treatment of virus-related respiratory infectious diseases and serves as an example of evidence-based clinical trials of other Chinese herbal medicines.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05929-8.

Management of Severe Influenza

Influenza infection causes severe illness in 3 to 5 million people annually, with up to an estimated 650,000 deaths per annum. As such, it represents an ongoing burden to health care systems and human health. Severe acute respiratory infection can occur, resulting in respiratory failure requiring intensive care support. Herein we discuss diagnostic approaches, including development of CLIA-waived point of care tests that allow rapid diagnosis and treatment of influenza. Bacterial and fungal coinfections in severe influenza pneumonia are associated with worse outcomes, and we summarize the approach and treatment options for diagnosis and treatment of bacterial and Aspergillus coinfection. We discuss the available drug options for the treatment of severe influenza, and treatments which are no longer supported by the evidence base. Finally, we describe the supportive management and ventilatory approach to patients with respiratory failure as a result of severe influenza in the intensive care unit.

Effect of a genetically engineered interferon-alpha versus traditional interferon-alpha in the treatment of moderate-to-severe COVID-19: a randomised clinical trial

BACKGROUND

There are few effective therapies for coronavirus disease 2019 (COVID-19) upon the outbreak of the pandemic. To compare the effectiveness of a novel genetically engineered recombinant super-compound interferon (rSIFN-co) with traditional interferon-alpha added to baseline antiviral agents (lopinavir-ritonavir or umifenovir) for the treatment of moderate-to-severe COVID-19.

METHOD

In this multicenter randomized (1:1) trial, patients hospitalized with moderate-to-severe COVID-19 received either rSIFN-co nebulization or interferon-alpha nebulization added to baseline antiviral agents for no more than 28 days. The primary endpoint was the time to clinical improvement. Secondary endpoints included the overall rate of clinical improvement assessed on day 28, the time to radiological improvement and virus nucleic acid negative conversion.

RESULTS

A total of 94 patients were included in the safety set (46 patients assigned to rSIFN-co group, 48 to interferon-alpha group). The time to clinical improvement was 11.5 days versus 14.0 days (95% CI 1.10 to 2.81, p = .019); the overall rate of clinical improvement on day 28 was 93.5% versus 77.1% (difference, 16.4%; 95% CI 3% to 30%); the time to radiological improvement was 8.0 days versus 10.0 days (p = .002), the time to virus nucleic acid negative conversion was 7.0 days versus 10.0 days (p = .018) in the rSIFN-co and interferon alpha arms, respectively. Adverse events were balanced with no deaths among groups.

CONCLUSIONS AND RELEVANCE

rSIFN-co was associated with a shorter time of clinical improvement than traditional interferon-alpha in the treatment of moderate-to-severe COVID-19 when combined with baseline antiviral agents. rSIFN-co therapy alone or combined with other antiviral therapy is worth to be further studied.Key messagesThere are few effective therapies for coronavirus disease 2019 (COVID-19) upon the outbreak of the pandemic. Interferon alphas, by inducing both innate and adaptive immune responses, have shown clinical efficacy in treating severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus.In this multicenter, head-to-head, randomized, clinical trial which included 94 participants with moderate-to-severe COVID-19, the rSIFN-co plus antiviral agents (lopinavir-ritonavir or umifenovir) was associated with a shorter time of clinical improvement than interferon-alpha plus antiviral agents.

Clinical and virological impact of single and dual infections with influenza A (H1N1) and SARS-CoV-2 in adult inpatients

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mimics the influenza A (H1N1) virus in terms of clinical presentation, transmission mechanism, and seasonal coincidence. Comprehensive data for the clinical severity of adult patients co-infected by both H1N1 and SARS-CoV-2, and, particularly, the relationship with PCR cycle threshold (Ct) values are not yet available. All participants in this study were tested for H1N1 and SARS-CoV-2 simultaneously at admission. Demographic, clinical, treatment, and laboratory data were extracted from electronic medical records and compared among adults hospitalized for H1N1 infection, SARS-CoV-2 infection and co-infection with both viruses. Ct values for viral RNA detection were further compared within SARS-CoV-2 and co-infection groups. Score on seven-category ordinal scale of clinical status at day 7 and day 14 were assessed. Among patients with monoinfection, H1N1 infection had higher frequency of onset symptoms but lower incidence of adverse events during hospitalization than SAR-CoV-2 infection (P < 0.05). Co-infection had an increased odds of acute kidney injury, acute heart failure, secondary bacterial infections, multilobar infiltrates and admittance to ICU than monoinfection. Score on seven-category scale at day 7 and day 14 was higher in patients with coinfection than patients with SAR-CoV-2 monoinfection (P<0.05). Co-infected patients had lower initial Ct values (referring to higher viral load) (median 32) than patients with SAR-CoV-2 monoinfection (median 36). Among co-infected patients, low Ct values were significantly and positively correlated with acute kidney injury and ARDS (P = 0.03 and 0.02, respectively). Co-infection by SARS-CoV-2 and H1N1 caused more severe disease than monoinfection by either virus in adult inpatients. Early Ct value could provide clues for the later trajectory of the co-infection. Multiplex molecular diagnostics for both viruses and early assessment of SAR-CoV-2 Ct values are recommended to achieve optimal treatment for improved clinical outcome.

The baseline enrolled 505 patients admitted to Guangzhou Eighth People’s Hospital (Guangzhou, Guangdong) with a diagnosis of COVID-19 or H1N1. All the patients were tested by both viruses at admission. Demographic, clinical, treatment, and laboratory data were extracted from electronic medical records and compared among adults (≥18 years) hospitalized for H1N1 infection (n = 220), SARS-CoV-2 infection (n = 249) and co-infection with both viruses (n = 36). The prevalence rate of H1N1 co-infection was 12.6% (36/285) among patients hospitalized with COVID-19. Co-infection affected a predominantly older age group and was associated with poorer clinical outcome. We also described the viral load trajectory in patients with diverse types of infection. Lower initial Ct values (higher viral loads in nasopharyngeal swabs) of co-infected patients was found to be associated with a higher number of adverse events and clinical symptoms. Considering the COVID-19 pandemic and a simultaneous epidemic of seasonal influenza, the data in China may critically inform future therapeutic or prophylactic strategies, especially for other developing countries.

Influenza polymerase inhibitor resistance: Assessment of the current state of the art - A report of the isirv Antiviral group

It is more than 20 years since the neuraminidase inhibitors, oseltamivir and zanamivir were approved for the treatment and prevention of influenza. Guidelines for global surveillance and methods for evaluating resistance were established initially by the Neuraminidase Inhibitor Susceptibility Network (NISN), which merged 10 years ago with the International Society for influenza and other Respiratory Virus Diseases (isirv) to become the isirv-Antiviral Group (isirv-AVG). With the ongoing development of new influenza polymerase inhibitors and recent approval of baloxavir marboxil, the isirv-AVG held a closed meeting in August 2019 to discuss the impact of resistance to these inhibitors. Following this meeting and review of the current literature, this article is intended to summarize current knowledge regarding the clinical impact of resistance to polymerase inhibitors and approaches for surveillance and methods for laboratory evaluation of resistance, both in vitro and in animal models. We highlight limitations and gaps in current knowledge and suggest some strategies for addressing these gaps, including the need for additional clinical studies of influenza antiviral drug combinations. Lessons learned from influenza resistance monitoring may also be helpful for establishing future drug susceptibility surveillance and testing for SARS-CoV-2.

Variation in COVID-19 disease severity at hospital admission over time and across hospitals: A multi-institution cohort of Michigan hospitals

ABSTRACT

During the spring 2020 COVID-19 surge, hospitals in Southeast Michigan were overwhelmed, and hospital beds were limited. However, it is unknown whether threshold for hospital admission varied across hospitals or over time.Using a statewide registry, we performed a retrospective cohort study. We identified adult patients hospitalized with COVID-19 in Southeast Michigan (3/1/2020-6/1/2020). We classified disease severity on admission using the World Health Organization (WHO) ordinal scale. Our primary measure of interest was the proportion of patients admitted on room air. We also determined the proportion without acute organ dysfunction on admission or any point during hospitalization. We quantified variation across hospitals and over time by half-month epochs.Among 1315 hospitalizations across 22 hospitals, 57.3% (754/1,315) were admitted on room air, and 26.1% (343/1,315) remained on room air for the duration of hospitalization. Across hospitals, the proportion of COVID-19 hospitalizations admitted on room air varied from 32.3% to 80.0%. Across half-month epochs, the proportion ranged from 49.4% to 69.4% and nadired in early April 2020. Among patients admitted on room air, 75.1% (566/754) had no acute organ dysfunction on admission, and 35.3% (266/754) never developed acute organ dysfunction at any point during hospitalization; there was marked variation in both proportions across hospitals. In-hospital mortality was 13.7% for patients admitted on room air vs 26.3% for patients requiring nasal cannula oxygen.Among patients hospitalized with COVID-19 during the spring 2020 surge in Southeast Michigan, more than half were on room air and a third had no acute organ dysfunction upon admission, but experienced high rates of disease progression and in-hospital mortality.

Theory and reality of antivirals against SARS-CoV-2

At present, over 180 million people have been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide and there have been more than 3.8 million deaths due to the virus. However, specific effective antiviral treatment for this infectious disease is absent. At the beginning of the epidemic, relevant cellular and animal experiments of antiviral treatment for SARS-CoV-2 were conducted based on the prior studies of SARS-CoV and Middle East respiratory syndrome coronavirus. Some antivirals were preliminarily validated to be potentially effective in the clinical settings. But as the epidemic continued and more studies were carried out, the efficacy of these antiviral drugs became controversial. This paper reviews the pharmacology and application of interferon, lopinavir/ritonavir, ribavirin, chloroquine, arbidol, favipiravir, remdesivir, and thymosin α1 in coronavirus disease 2019. The actual effect of these drugs remains controversial. Meanwhile, the efficacy and safety of these drugs for patients with coronavirus disease 2019 still need to be explored.

Preparing for the 2020-2021 influenza season

The COVID-19 pandemic has altered health seeking behaviors and has increased attention to non-pharmaceutical interventions that reduce the risk of transmission of respiratory viruses including SARS-CoV-2 and influenza. While the potential impact of the COVID-19 pandemic on influenza is not fully known, in the Southern hemisphere influenza infection rates appear to be very low. Influenza vaccine efficacy for 2019-2020 season was comparable to prior season and influenza vaccine recommendations for pediatric immunizations remain similar to prior years. Influenza treatments continue to include neuraminidase inhibitors as well as baloxavir for treatment and in some instances prophylaxis.

Investigation of the disease process and drug combinations in patients with suspected/confirmed COVID-19 using favipiravir

AIMS

It is aimed to investigate the disease processes and drug combinations in patients who received favipiravir treatment.

METHODS

This cross-sectional, analytical and retrospective study included all patients aged ≥18 years (n = 502) who were hospitalised in Samsun, Turkey, for COVID-19 and were given favipiravir from the date between 25 March 2020 and 3 June 2020.

RESULTS

In total, 58.6% (n = 294) of the patients were male and 24.5% (n = 123) were between the ages of 71 and 80 years. During the first case process, the mortality rate was 19.9%, whereas the rate of those who were discharged as is/followed up at home for 14 days was 37.3%. During the second case process, the mortality rate was 6.2%, and the rate of those who was discharged as is/followed up at home for 14 days was 65.6%. The mean length of hospital stay was 10.61 ± 8.17 days for the first and 7.97 ± 4.16 days for the second hospitalisation; this difference was significant. Mortality risk of those who used Tocilizumab or vitamin C beside Favipiravir was higher than those who did not. The length of hospital stay was higher in patients using tocilizumab than in those who did not (P < .001).

CONCLUSION

Administration of favipiravir later in the course of the disease makes it difficult to achieve the true efficacy expected from the drug and also makes it difficult for other combination drugs to contribute to survival. Favipiravir may also be effective in case of recurrence.

An Assessment of the Impact of Coronavirus Disease (COVID-19) Pandemic on National Antimicrobial Consumption in Jordan

Coronavirus disease 2019 (COVID-19) has overlapping clinical characteristics with bacterial respiratory tract infection, leading to the prescription of potentially unnecessary antibiotics. This study aimed at measuring changes and patterns of national antimicrobial use for one year preceding and one year during the COVID-19 pandemic. Annual national antimicrobial consumption for 2019 and 2020 was obtained from the Jordan Food and Drug Administration (JFDA) following the WHO surveillance methods. The WHO Access, Watch, and Reserve (AWaRe) classification was used. Total antibiotic consumption in 2020 (26.8 DDD per 1000 inhabitants per day) decreased by 5.5% compared to 2019 (28.4 DDD per 1000 inhabitants per day). There was an increase in the use of several antibiotics during 2020 compared with 2019 (third generation cephalosporins (19%), carbapenems (52%), macrolides (57%), and lincosamides (106%)). In 2020, there was a marked reduction in amoxicillin use (-53%), while the use of azithromycin increased by 74%. National antimicrobial consumption of the Access group decreased by 18% from 2019 to 2020 (59.1% vs. 48.1% of total consumption). The use of the Watch group increased in 2020 by 26%. The study highlighted an increase in the use of certain antibiotics during the pandemic period that are known to be associated with increasing resistance. Efforts to enhance national antimicrobial stewardship are needed to ensure rational use of antimicrobials.

Coalescence of co-infection and antimicrobial resistance with SARS-CoV-2 infection: The blues of post-COVID-19 world

In viral respiratory infections, bacterial co-pathogens are widely known to co-infect, and they significantly increase the morbidity and mortality rate. During the influenza season, the advent of 2019-nCoV (novel coronavirus) has led to the widespread use of oral and intravenous antibiotics and inhibitors of neuraminidase enzyme. Owing to causes such as extended intubation, the ubiquitous use of intrusive catheters, and compromised host immunity, coronavirus disease (COVID-19) patients are at heightened risk of secondary bacterial and fungal infections, leading to the difficulty in their treatment. Apart from the pandemic, the primary risk is a likely surge in multidrug resistance. In this work, we evaluated the coalescence of present co-infection alongside the COVID-19 and post-pandemic antimicrobial resistance due to high ongoing drug use for the treatment of COVID-19. We found that while there is currently limited evidence of bacterial infections in COVID-19, available proof supports the restricted use of antibiotics from an antibiotic stewardship viewpoint, primarily upon entry. Paramount attempts should be made to collect sputum and blood culture samples as well as pneumococcal urinary antigen monitoring in order to endorse stringent antibiotic usage. For antimicrobial stewardship, inflammatory markers like procalcitonin have been added, but such biomarkers are typically upraised in COVID-19. Antimicrobials cannot be completely removed in wastewater treatment plants (WWTPs) and once they enter the water environment, possesses a great risk of inducing resistance to drugs in microbes. Hence, their prescription and administrations should be regulated and alternate solutions such as vaccines, preventive measures and personal hygiene should be given top priority. It is imperative to establish an antimicrobial strategy discrete to COVID-19, as this pandemic has caused an outbreak of numerous other associated diseases and has the potential to drive microbial resistance. Coordinated plans are essential for this at the citizen, health-care and policy levels.

COVID-19 Impacts, Diagnosis and Possible Therapeutic Techniques: A Comprehensive Review

BACKGROUND

The spread of COVID-19 has become a growing cause of mortalities over the globe since its major outbreak in December 2019. The scientific and medical communities are rallying to study different strains and probable mutations to develop more rapid and reliable molecular diagnostic tests and possible therapeutic approaches for SARS-CoV-2.

INTRODUCTION

In the first section, following the introductory part, we shed light on structural and pathogenic features of SARS-CoV-2 and risk factors related to age, gender, neonatal and comorbidities. The next section summarizes the current diagnostic tests for COVID-19, such as nucleic acid and computed tomography (CT) techniques, with further emphasis on emerging diagnostic approaches for COVID-19.

METHODS

Further, we also review the ongoing therapeutic practices which can block virus-host interaction, cease viral proliferation or inhibit hyperbolic host immune response with subsections on drug therapy, cell therapy, immunotherapy and herbal medicines that are being used for the possible treatment of patients.

RESULTS AND CONCLUSION

Among the different promising drugs, remdesivir, by inhibiting the RNA-dependent RNA-Polymerase activity, gives much better results, including declined viral load and quick lung tissue recovery. The long-lasting repercussions of COVID-19 have also been discussed at the end. In this review, we have also critically discussed the progress in several vaccines that are under development.

Drug combination therapy for emerging viral diseases

Effective therapeutics to combat emerging viral infections are an unmet need. Historically, treatments for chronic viral infections with single drugs have not been successful, as exemplified by human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections. Combination therapy for these diseases has led to improved clinical outcomes with dramatic reductions in viral load, morbidity, and mortality. Drug combinations can enhance therapeutic efficacy through additive, and ideally synergistic, effects for emerging and re-emerging viruses, such as influenza, severe acute respiratory syndrome-coronavirus (SARS-CoV), Middle East respiratory syndrome (MERS)-CoV, Ebola, Zika, and SARS-coronavirus 2 (CoV-2). Although novel drug development through traditional pipelines remains a priority, in the interim, effective synergistic drug candidates could be rapidly identified by drug-repurposing screens, facilitating accelerated paths to clinical testing and potential emergency use authorizations.

Influenza Polymerase Inhibitors: Mechanisms of Action and Resistance

The influenza virus RNA-dependent RNA polymerase is highly conserved among influenza A, B, C, and D viruses. It comprises three subunits: polymerase basic protein 1 (PB1), polymerase basic protein 2 (PB2), and polymerase acidic protein (PA) in influenza A and B viruses or polymerase 3 protein (P3) in influenza C and D viruses. Because this polymerase is essential for influenza virus replication, it has been considered as a target for antiviral agents. Recently, several polymerase inhibitors that target each subunit have been developed. This review discusses the mechanism of action, antiviral activity, and emergence of resistance to three inhibitors approved for the treatment of influenza or in late-phase clinical trials: the PB1 inhibitor favipiravir, the PB2 inhibitor pimodivir, and the PA inhibitor baloxavir marboxil.