Influenza A viruses escape from MxA restriction at the expense of efficient nuclear vRNP import

Heterozygous and generalist MxA super-restrictors overcome breadth-specificity tradeoffs in antiviral restriction

Antiviral restriction factors such as MxA (myxovirus resistance protein A) inhibit a broad range of viruses. However, they face the challenge of maintaining this breadth as viruses evolve to escape their defense. Viral escape drives restriction factors to evolve rapidly, selecting for amino acid changes at their virus-binding interfaces to regain defense. How do restriction factors balance the breadth of antiviral functions against the need to evolve specificity against individual escaping viruses? We explored this question in human MxA, which uses its rapidly evolving loop L4 as the specificity determinant for orthomyxoviruses such as THOV and IAV. Previous combinatorial mutagenesis of rapidly evolving residues in human MxA loop L4 revealed variants with a ten-fold increase in potency against THOV. However, this strategy did not yield improved IAV restriction, suggesting a strong tradeoff between antiviral specificity and breadth. Here, using a modified combinatorial mutagenesis strategy, we find 'super-restrictor' MxA variants with over ten-fold enhanced restriction of the avian IAV strain H5N1 but reduced THOV restriction. Analysis of super-restrictor MxA variants reveals that the identity of residue 561 explains most of MxA's breadth-specificity tradeoff in H5N1 versus THOV restriction. However, rare 'generalist' super-restrictors with enhanced restriction of both viruses allow MxA to overcome the breadth-specificity tradeoff. Finally, we show that a heterozygous combination of two 'specialist' super-restrictors, one against THOV and the other against IAV, enhances restriction against both viruses. Thus, two strategies enable restriction factors such as MxA to increase their restriction of diverse viruses to overcome breadth-specificity tradeoffs that may be pervasive in host-virus conflicts.

Substandard and falsified ivermectin tablets obtained for self-medication during the COVID-19 pandemic as a source of potential harm

In 2019, a global viral pandemic, due to the SARS-CoV-2 virus, broke out. Soon after, the search for a vaccine and/or antiviral medicine began. One of the candidate antiviral medicines tested was ivermectin. Although several health authorities warned the public against the use of this medicine outside clinical trials, the drug was widely used at the end of 2020 and in 2021. Simultaneously, several reports started to emerge demonstrating serious adverse effects after self-medicating with ivermectin. It stands to reason that the self-administration of substandard or falsified (SF) medicines bearing harmful quality deficiencies have contributed to this phenomenon. In order to have a better view on the nature of these harmful quality deficiencies, SF ivermectin samples, intercepted in large quantities by the Belgian regulatory agencies during the period 2021-2022, were analyzed in our official medicines control laboratory. None of the samples (n = 19) were compliant to the quality criteria applicable to medicinal products. These SF products either suffered from a systematic underdosing of the active pharmaceutical ingredient or were severely contaminated with bacteria, two of which were contaminated with known pathogens that cause gastrointestinal illness upon oral intake. In addition to the direct risks of self-medicating with such a product, the improper usage and dosage of ivermectin medication might also facilitate ivermectin tolerance or resistance in parasites. This may have detrimental consequences on a global scale, certainly as the number of newly developed active pharmaceutical ingredients that can safely be used to combat parasites is rather scarce.

Morphologic characterization and cytokine response of chicken bone-marrow derived dendritic cells to infection with high and low pathogenic avian influenza virus

Dendritic cells (DCs) are professional antigen-presenting cells, which are key components of the immune system and involved in early immune responses. DCs are specialized in capturing, processing, and presenting antigens to facilitate immune interactions. Chickens infected with avian influenza virus (AIV) demonstrate a wide range of clinical symptoms, based on pathogenicity of the virus. Low pathogenic avian influenza (LPAI) viruses typically induce mild clinical signs, whereas high pathogenic avian influenza (HPAI) induce more severe disease, which can lead to death. For this study, chicken bone marrow-derived DC (ckBM-DC)s were produced and infected with high and low pathogenic avian influenza viruses of H5N2 or H7N3 subtypes to characterize innate immune responses, study effect on cell morphologies, and evaluate virus replication. A strong proinflammatory response was observed at 8 hours post infection, via upregulation of chicken interleukin-1β and stimulation of the interferon response pathway. Microscopically, the DCs underwent morphological changes from classic elongated dendrites to a more general rounded shape that eventually led to cell death with the presence of scattered cellular debris. Differences in onset of morphologic changes were observed between H5 and H7 subtypes. Increases in viral titers demonstrated that both HPAI and LPAI are capable of infecting and replicating in DCs. The increase in activation of infected DCs may be indicative of a dysregulated immune response typically seen with HPAI infections.

Deep mutational scanning of H5 hemagglutinin to inform influenza virus surveillance

H5 influenza is a potential pandemic threat. Previous studies have identified molecular phenotypes of the viral hemagglutinin (HA) protein that contribute to pandemic risk, including cell entry, receptor preference, HA stability, and reduced neutralization by polyclonal sera. Here we use pseudovirus deep mutational scanning to measure how all mutations to a clade 2.3.4.4b H5 HA affect each phenotype. We identify mutations that allow HA to better bind a2-6-linked sialic acids, and show that some viruses already carry mutations that stabilize HA. We also identify recent viral strains with reduced neutralization to sera elicited by candidate vaccine virus. Overall, the systematic nature of deep mutational scanning combined with the safety of pseudoviruses enables comprehensive characterization of mutations to inform surveillance of H5 influenza.

Host Innate Antiviral Response to Influenza A Virus Infection: From Viral Sensing to Antagonism and Escape

Influenza virus possesses an RNA genome of single-stranded, negative-sensed, and segmented configuration. Influenza virus causes an acute respiratory disease, commonly known as the "flu" in humans. In some individuals, flu can lead to pneumonia and acute respiratory distress syndrome. Influenza A virus (IAV) is the most significant because it causes recurring seasonal epidemics, occasional pandemics, and zoonotic outbreaks in human populations, globally. The host innate immune response to IAV infection plays a critical role in sensing, preventing, and clearing the infection as well as in flu disease pathology. Host cells sense IAV infection through multiple receptors and mechanisms, which culminate in the induction of a concerted innate antiviral response and the creation of an antiviral state, which inhibits and clears the infection from host cells. However, IAV antagonizes and escapes many steps of the innate antiviral response by different mechanisms. Herein, we review those host and viral mechanisms. This review covers most aspects of the host innate immune response, i.e., (1) the sensing of incoming virus particles, (2) the activation of downstream innate antiviral signaling pathways, (3) the expression of interferon-stimulated genes, (4) and viral antagonism and escape.

Enhanced In Vitro Antiviral Activity of Ivermectin-Loaded Nanostructured Lipid Carriers against Porcine Epidemic Diarrhea Virus via Improved Intracellular Delivery

Porcine epidemic diarrhea virus (PEDV) is an acute enteric coronavirus, inducing watery diarrhea and high mortality in piglets, leading to huge economic losses in global pig industry. Ivermectin (IVM), an FDA-approved antiparasitic agent, is characterized by high efficacy and wide applicability. However, the poor bioavailability limits its application. Since the virus is parasitized inside the host cells, increasing the intracellular drug uptake can improve antiviral efficacy. Hence, we aimed to develop nanostructured lipid carriers (NLCs) to enhance the antiviral efficacy of IVM. The findings first revealed the capacity of IVM to inhibit the infectivity of PEDV by reducing viral replication with a certain direct inactivation effect. The as-prepared IVM-NLCs possessed hydrodynamic diameter of 153.5 nm with a zeta potential of -31.5 mV and high encapsulation efficiency (95.72%) and drug loading (11.17%). IVM interacted with lipids and was enveloped in lipid carriers with an amorphous state. Furthermore, its encapsulation in NLCs could enhance drug internalization. Meanwhile, IVM-NLCs inhibited PEDV proliferation by up to three orders of magnitude in terms of viral RNA copies, impeding the accumulation of reactive oxygen species and mitigating the mitochondrial dysfunction caused by PEDV infection. Moreover, IVM-NLCs markedly decreased the apoptosis rate of PEDV-induced Vero cells. Hence, IVM-NLCs showed superior inhibitory effect against PEDV compared to free IVM. Together, these results implied that NLCs is an efficient delivery system for IVM to improve its antiviral efficacy against PEDV via enhanced intracellular uptake.

The immune-evasive proline-283 substitution in influenza nucleoprotein increases aggregation propensity without altering the native structure

Nucleoprotein (NP) is a key structural protein of influenza ribonucleoprotein complexes and is central to viral RNA packing and trafficking. NP also determines the sensitivity of influenza to myxovirus resistance protein 1 (MxA), an innate immunity factor that restricts influenza replication. A few critical MxA-resistant mutations have been identified in NP, including the highly conserved proline-283 substitution. This essential proline-283 substitution impairs influenza growth, a fitness defect that becomes particularly prominent at febrile temperature (39°C) when host chaperones are depleted. Here, we biophysically characterize proline-283 NP and serine-283 NP to test whether the fitness defect is caused by the proline-283 substitution introducing folding defects. We show that the proline-283 substitution changes the folding pathway of NP, making NP more aggregation prone during folding, but does not alter the native structure of the protein. These findings suggest that influenza has evolved to hijack host chaperones to promote the folding of otherwise biophysically incompetent viral proteins that enable innate immune system escape.

Two complete 1918 influenza A/H1N1 pandemic virus genomes characterized by next-generation sequencing using RNA isolated from formalin-fixed, paraffin-embedded autopsy lung tissue samples along with evidence of secondary bacterial co-infection

The 1918 influenza pandemic was the most devastating respiratory pandemic in modern human history, with 50-100 million deaths worldwide. Here, we characterized the complete genomes of influenza A virus (IAV) from two fatal cases during the fall wave of 1918 influenza A (H1N1) pandemic in the United States, one from Walter Reed Army Hospital in Washington, DC, and the other from Camp Jackson, SC. The two complete IAV genomes were obtained by combining Illumina deep sequencing data from both total RNA and influenza viral genome-enriched libraries along with Sanger sequencing data from PCR across the sequencing gaps. This study confirms the previously reported 1918 IAV genomes and increases the total number of available complete or near-complete influenza viral genomes of the 1918 pandemic from four to six. Sequence comparisons among them confirm that the genomes of the 1918 pandemic virus were highly conserved during the main wave of the pandemic with geographic separation in North America and Europe. Metagenomic analyses revealed bacterial co-infections in both cases. Interestingly, in the Washington, DC, case, evidence is presented of the first reported Rhodococcus-influenza virus co-infection.

IMPORTANCE

This study applied modern molecular biotechnology and high-throughput sequencing to formalin-fixed, paraffin-embedded autopsy lung samples from two fatal cases during the fall wave of the 1918 influenza A (H1N1) pandemic in the United States. Complete influenza genomes were obtained from both cases, which increases the total number of available complete or near-complete influenza genomes of the 1918 pandemic virus from four to six. Sequence analysis confirms that the 1918 pandemic virus was highly conserved during the main wave of the pandemic with geographic separation in North America and Europe. Metagenomic analyses revealed bacterial co-infections in both cases, including the first reported evidence of Rhodococcus-influenza co-infection. Overall, this study offers a detailed view at the molecular level of the very limited samples from the most devastating influenza pandemic in modern human history.

Identification of inositol monophosphatase as a broad-spectrum antiviral target of ivermectin

Ivermectin has broad-spectrum antiviral activities. Despite the failure in clinical application of COVID-19, it can serve as a lead compound for the development of more effective broad-spectrum antivirals, for which a better understanding of its antiviral mechanisms is essential. We thus searched for potential novel targets of ivermectin in host cells by label-free thermal proteomic profiling using Huh-7 cells. Inositol monophosphatase (IMPase) was found among the proteins with shifted thermal stability by ivermectin. Ivermectin could inhibit IMPase activity and reduce cellular myo-inositol and phosphatidylinositol-4-phosphate levels. On the other hand, inositol could impair the antiviral activity of ivermectin and lithium, an IMPase inhibitor with known antiviral activity. As phosphatidylinositol phosphate is crucial for the replication of many RNA viruses, inhibition of cellular myo-inositol biosynthesis may be an important antiviral mechanism of ivermectin. Hence, inhibition of IMPase could serve as a potential target for broad-spectrum antiviral development.

Influenza Virus Host Restriction Factors: The ISGs and Non-ISGs

Influenza virus has been one of the most prevalent and researched viruses globally. Consequently, there is ample information available about influenza virus lifecycle and pathogenesis. However, there is plenty yet to be known about the determinants of influenza virus pathogenesis and disease severity. Influenza virus exploits host factors to promote each step of its lifecycle. In turn, the host deploys antiviral or restriction factors that inhibit or restrict the influenza virus lifecycle at each of those steps. Two broad categories of host restriction factors can exist in virus-infected cells: (1) encoded by the interferon-stimulated genes (ISGs) and (2) encoded by the constitutively expressed genes that are not stimulated by interferons (non-ISGs). There are hundreds of ISGs known, and many, e.g., Mx, IFITMs, and TRIMs, have been characterized to restrict influenza virus infection at different stages of its lifecycle by (1) blocking viral entry or progeny release, (2) sequestering or degrading viral components and interfering with viral synthesis and assembly, or (3) bolstering host innate defenses. Also, many non-ISGs, e.g., cyclophilins, ncRNAs, and HDACs, have been identified and characterized to restrict influenza virus infection at different lifecycle stages by similar mechanisms. This review provides an overview of those ISGs and non-ISGs and how the influenza virus escapes the restriction imposed by them and aims to improve our understanding of the host restriction mechanisms of the influenza virus.

The nuclear entry of the aryl hydrocarbon receptor (AHR) relies on the first nuclear localization signal and can be negatively regulated through IMPα/β specific inhibitors

The human aryl hydrocarbon receptor (AHR) undergoes continuous shuttling between nucleus and cytoplasm. Binding to exogenous or endogenous ligands promotes its rapid nuclear import. The proposed mechanism for the ligand-dependent import is based on exposing the bipartite nuclear localisation signal (NLS) to members of the importin (IMP) superfamily. Among this, the molecular interactions involved in the basal import still need to be clarified. Utilizing fluorescently fused AHR variants, we recapitulated and characterized AHR localization and nucleo-cytoplasmic shuttling in living cells. Analysis of AHR variants carrying NLS point mutations demonstrated a mandatory role of first (13RKRRK17) and second (37KR-R40) NLS segments on the basal import of AHR. Further experiments indicated that ligand-induced import is mainly regulated through the first NLS, while the second NLS is supportive but not essential. Additionally, applying IMPα/β specific inhibitors, ivermectin (IVM) and importazole (IPZ), slowed down the ligand-induced import and, correspondingly, decreased the basal nuclear accumulation of the receptor. In conclusion, our data show that ligand-induced and basal nuclear entry of AHR rely on the same mechanism but are controlled uniquely by the two NLS components.

The Immune-Evasive Proline 283 Substitution in Influenza Nucleoprotein Increases Aggregation Propensity Without Altering the Native Structure

Nucleoprotein (NP) is a key structural protein of influenza ribonucleoprotein complexes and is central to viral RNA packing and trafficking. In human cells, the interferon induced Myxovirus resistance protein 1 (MxA) binds to NP and restricts influenza replication. This selection pressure has caused NP to evolve a few critical MxA-resistant mutations, particularly the highly conserved Pro283 substitution. Previous work showed that this essential Pro283 substitution impairs influenza growth, and the fitness defect becomes particularly prominent at febrile temperature (39 °C) when host chaperones are depleted. Here, we biophysically characterize Pro283 NP and Ser283 NP to test if the fitness defect is owing to Pro283 substitution introducing folding defects. We show that the Pro283 substitution changes the folding pathway of NP without altering the native structure, making NP more aggregation prone during folding. These findings suggest that influenza has evolved to hijack host chaperones to promote the folding of otherwise biophysically incompetent viral proteins that enable innate immune system escape.

Teaser

Pro283 substitution in flu nucleoprotein introduces folding defects, and makes influenza uniquely dependent on host chaperones.

Increased In Vivo Exposure of N-(4-Hydroxyphenyl) Retinamide (4-HPR) to Achieve Plasma Concentrations Effective against Dengue Virus

N-(4-hydroxyphenyl) retinamide (4-HPR, or fenretinide) has promising in vitro and in vivo antiviral activity against a range of flaviviruses and an established safety record, but there are challenges to its clinical use. This study evaluated the in vivo exposure profile of a 4-HPR dosage regime previously shown to be effective in a mouse model of severe dengue virus (DENV) infection, comparing it to an existing formulation for human clinical use for other indications and developed/characterised self-emulsifying lipid-based formulations of 4-HPR to enhance 4-HPR in vivo exposure. Pharmacokinetic (PK) analysis comprising single-dose oral and IV plasma concentration-time profiles was performed in mice; equilibrium solubility testing of 4-HPR in a range of lipids, surfactants and cosolvents was used to inform formulation approaches, with lead formulation candidates digested in vitro to analyse solubilisation/precipitation prior to in vivo testing. PK analysis suggested that effective plasma concentrations could be achieved with the clinical formulation, while novel lipid-based formulations achieved > 3-fold improvement. Additionally, 4-HPR exposure was found to be limited by both solubility and first-pass intestinal elimination but could be improved through inhibition of cytochrome P450 (CYP) metabolism. Simulated exposure profiles suggest that a b.i.d dosage regime is likely to maintain 4-HPR above the minimum effective plasma concentration for anti-DENV activity using the clinical formulation, with new formulations/CYP inhibition viable options to increase exposure in the future.

Potential treatments of COVID-19: Drug repurposing and therapeutic interventions

The coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The infection is caused when Spike-protein (S-protein) present on the surface of SARS-CoV-2 interacts with human cell surface receptor, Angiotensin-converting enzyme 2 (ACE2). This binding facilitates SARS-CoV-2 genome entry into the human cells, which in turn causes infection. Since the beginning of the pandemic, many different therapies have been developed to combat COVID-19, including treatment and prevention. This review is focused on the currently adapted and certain other potential therapies for COVID-19 treatment, which include drug repurposing, vaccines and drug-free therapies. The efficacy of various treatment options is constantly being tested through clinical trials and in vivo studies before they are made medically available to the public.

A comprehensive review on pharmacologic agents, immunotherapies and supportive therapeutics for COVID-19

The emergence of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected many countries throughout the world. As urgency is a necessity, most efforts have focused on identifying small molecule drugs that can be repurposed for use as anti-SARS-CoV-2 agents. Although several drug candidates have been identified using in silico method and in vitro studies, most of these drugs require the support of in vivo data before they can be considered for clinical trials. Several drugs are considered promising therapeutic agents for COVID-19. In addition to the direct-acting antiviral drugs, supportive therapies including traditional Chinese medicine, immunotherapies, immunomodulators, and nutritional therapy could contribute a major role in treating COVID-19 patients. Some of these drugs have already been included in the treatment guidelines, recommendations, and standard operating procedures. In this article, we comprehensively review the approved and potential therapeutic drugs, immune cells-based therapies, immunomodulatory agents/drugs, herbs and plant metabolites, nutritional and dietary for COVID-19.

Suppression of classical nuclear import pathway by importazole and ivermectin inhibits rotavirus replication

BACKGROUND

Rotavirus is the foremost cause of acute gastroenteritis among infants in resource-poor countries, causing severe morbidity and mortality. The currently available rotavirus vaccines are effective in reducing severity of the disease but not the infection rates, thus antivirals as an adjunct therapy are needed to reduce the morbidity in children. Viruses rely on host cellular machinery for nearly every step of the replication cycle. Therefore, targeting host factors that are indispensable for virus replication could be a promising strategy.

OBJECTIVES

To assess the therapeutic potential of ivermectin and importazole against rotaviruses.

METHODS

Antirotaviral activity of importazole and ivermectin was measured against various rotavirus strains (RV-SA11, RV-Wa, RV-A5-13, RV-EW) in vitro and in vivo by quantifying viral protein expression by western blot, analysing viroplasm formation by confocal microscopy, and measuring virus yield by plaque assay.

RESULTS

Importin-β1 and Ran were found to be induced during rotavirus infection. Knocking down importin-β1 severely impaired rotavirus replication, suggesting a critical role for importin-β1 in the rotavirus life cycle. In vitro studies revealed that treatment of ivermectin and importazole resulted in reduced synthesis of viral proteins, diminished production of infectious virus particles, and decrease in viroplasm-positive cells. Mechanistic study proved that both drugs perform antirotavirus activity by inhibiting the function of importin-β1. In vivo investigations in mice also confirmed the antirotavirus potential of importazole and ivermectin at non-toxic doses. Treatments of rotavirus-infected mice with either drug resulted in diminished shedding of viral particles in the stool sample, reduced expression of viral protein in the small intestine and restoration of damaged intestinal villi comapared to untreated infected mice.

CONCLUSIONS

The study highlights the potential of importazole and ivermectin as antirotavirus therapeutics.

Increased Polymerase Activity of Zoonotic H7N9 Allows Partial Escape from MxA

The interferon-induced myxovirus resistance protein A (MxA) is a potent restriction factor that prevents zoonotic infection from influenza A virus (IAV) subtype H7N9. Individuals expressing antivirally inactive MxA variants are highly susceptible to these infections. However, human-adapted IAVs have acquired specific mutations in the viral nucleoprotein (NP) that allow escape from MxA-mediated restriction but that have not been observed in MxA-sensitive, human H7N9 isolates. To date, it is unknown whether H7N9 can adapt to escape MxA-mediated restriction. To study this, we infected Rag2-knockout (Rag2^-/-) mice with a defect in T and B cell maturation carrying a human MxA transgene (MxA^tg/-Rag2^-/-). In these mice, the virus could replicate for several weeks facilitating host adaptation. In MxA^tg/-Rag2^-/-, but not in Rag2^-/- mice, the well-described mammalian adaptation E627K in the viral polymerase subunit PB2 was acquired, but no variants with MxA escape mutations in NP were detected. Utilizing reverse genetics, we could show that acquisition of PB2 E627K allowed partial evasion from MxA restriction in MxA^tg/tg mice. However, pretreatment with type I interferon decreased viral replication in these mice, suggesting that PB2 E627K is not a true MxA escape mutation. Based on these results, we speculate that it might be difficult for H7N9 to acquire MxA escape mutations in the viral NP. This is consistent with previous findings showing that MxA escape mutations cause severe attenuation of IAVs of avian origin.

Possible Role of Ivermectin Mucoadhesive Nanosuspension Nasal Spray in Recovery of Post-COVID-19 Anosmia

Purpose

Anosmia or hyposmia, with or without taste changes, are common symptoms that occur in SARS-CoV-2 infection and frequently persist as post-COVID-19 manifestations. This is the first trial to assess the potential value of using local ivermectin in the form of a mucoadhesive nanosuspension nasal spray to treat post-COVID-19 anosmia.

Methods

It is a controlled, randomized trial. Participants were recruited from South Valley University Hospitals in Qena, Upper Egypt, from the ENT and Chest Diseases Departments and outpatient clinics. Patients with persistent post COVID-19 anosmia were randomly divided into two groups, the first group "ivermectin group" included 49 patients treated by ivermectin nanosuspension mucoadhesive nasal spray (two puffs per day). The second group included 47 patients "placebo group" who received saline nasal spray. Follow- up of anosmia [using Visual analogue scale (VAS)] in all patients for three months or appearance of any drug related side effects was done.

Results

The mean duration of pre-treatment post COVID-19 anosmia was 19.5± 5.8 days in the ivermectin group and 19.1± 5.9 days in the placebo group,p˃0.05. Regarding the median duration of anosmia recovery, the ivermectin group recovered from post COVID-19 anosmia in 13 days compared to 50 days in the placebo group, p˂ 0.001. Following the first week of ivermectin nanosuspension mucoadhesive nasal spray therapy, the ivermectin group had a significantly higher percentage of anosmia recovery (59.2%) than the placebo group (27.7%), p˂ 0.01, with no significant differences in recovery rates between the two groups at 1, 2, and 3 months of follow up, p˃0.05.

Conclusion

In the small number of patients treated, local Ivermectin exhibited no side effects. In persistent post-COVID-19 anosmia, it could be used for one week at the most as the treatment was extended to one, two and three months, with no difference in recovery compared to the placebo treatment.

Trial Registration No

NCT04951362.

The effect of ivermectin on the viral load and culture viability in early treatment of nonhospitalized patients with mild COVID-19 - a double-blind, randomized placebo-controlled trial

OBJECTIVES

Ivermectin, an antiparasitic agent, also has antiviral properties. In this study, we aimed to assess whether ivermectin has anti-SARS-CoV-2 activity.

METHODS

In this double-blinded trial, we compared patients receiving ivermectin for 3 days versus placebo in nonhospitalized adult patients with COVID-19. A reverse transcriptase-polymerase chain reaction from a nasopharyngeal swab was obtained at recruitment and every 2 days for at least 6 days. The primary endpoint was a reduction of viral load on the sixth day as reflected by cycle threshold level >30 (noninfectious level). The primary outcome was supported by the determination of viral-culture viability.

RESULTS

Of 867 patients screened, 89 were ultimately evaluated per-protocol (47 ivermectin and 42 placeboes). On day 6, the odds ratio (OR) was 2.62 (95% confidence interval [CI]: 1.09-6.31) in the ivermectin arm, reaching the endpoint. In a multivariable logistic regression model, the odds of a negative test on day 6 were 2.28 times higher in the ivermectin group but reached significance only on day 8 (OR 3.70; 95% CI: 1.19-11.49, P = 0.02). Culture viability on days 2 to 6 was positive in 13.0% (3/23) of ivermectin samples versus 48.2% (14/29) in the placebo group (P = 0.008).

CONCLUSION

There were lower viral loads and less viable cultures in the ivermectin group, which shows its anti-SARS-CoV-2 activity. It could reduce transmission in these patients and encourage further studies with this drug.

Potential therapeutic effects of Ivermectin in COVID-19

COVID-19 is a critical pandemic that affected communities around the world, and there is currently no specific drug treatment for it. The virus enters the human cells via spikes and induces cytokine production and finally arrests the cell cycle. Ivermectin shows therapeutic potential for treating COVID-19 infection based on in vitro studies. Docking studies have shown a strong affinity between Ivermectin and some virulence factors of COVID-19. Notably, clinical evidence has demonstrated that Ivermectin with usual doses is effective by both the prophylactic and therapeutic approaches in all phases of the disease. Ivermectin inhibits both the adhesion and replication of the virus. Local therapy of the lung with Ivermectin or combination therapy may get better results and decrease the dose of the drug.

Effects of Avermectins on the Environment Based on Its Toxicity to Plants and Soil Invertebrates-a Review

Avermectins are pharmaceutical drugs widely used mainly in livestock to combat both ectoparasites and endoparasites. Drugs belonging to this family include ivermectin, abamectin, doramectin, selamectin, eprinomectin, and emamectin benzoate, and they share similar chemical characteristics. When administered to livestock, between 80 and 98% of the drug is estimated to leave the body without being metabolized in feces, thus reaching the soil. For this reason, concern for avermectin contamination in soil is increasing, and researchers are focused on estimating the effects on non-target organisms, such as plants and soil invertebrates. This review aimed to compile and discuss updated data of avermectin toxicity on non-target organisms to better comprehend its effect on the environment. Effects on plants are scarcely studied, since they were not believed to absorb these drugs. However, recent studies suggest that plants can be negatively affected. Regarding soil invertebrates, negative effects such as increased mortality and reduced reproduction are best known to dung-beetles. Recently, some studies have also suggested that earthworms, springtails, and enchytraeids can be adversely affected by avermectin exposure. Since ivermectin was the first avermectin marketed, most of the data refers to this product. According to new data on scientific literature, avermectins can now be considered harmful to non-target organisms, and its prudent use is recommended in order to reduce negative effects on the environment. For future investigations, inclusion of avermectins other than ivermectin, as well as field and "omics" studies is suggested.

Are pigs overestimated as a source of zoonotic influenza viruses?

Background

Swine influenza caused by influenza A viruses (IAV) directly affects respiratory health and indirectly impairs reproduction rates in pigs causing production losses. In Europe, and elsewhere, production systems have intensified featuring fewer holdings but, in turn, increased breeding herd and litter sizes. This seems to foster swine IAV (swIAV) infections with respect to the entrenchment within and spread between holdings. Disease management of swine influenza is difficult and relies on biosecurity and vaccination measures. Recently discovered and widely proliferating forms of self-sustaining modes of swIAV infections in large swine holdings challenge these preventive concepts by generating vaccine-escape mutants in rolling circles of infection.

Main body

The most recent human IAV pandemic of 2009 rooted at least partly in IAV of porcine origin highlighting the zoonotic potential of swIAV. Pigs constitute a mixing vessel of IAV from different species including avian and human hosts. However, other host species such as turkey and quail but also humans themselves may also act in this way; thus, pigs are not essentially required for the generation of IAV reassortants with a multispecies origin. Since 1918, all human pandemic influenza viruses except the H2N2 virus of 1958 have been transmitted in a reverse zoonotic mode from human into swine populations. Swine populations act as long-term reservoirs of these viruses. Human-derived IAV constitute a major driver of swIAV epidemiology in pigs. Swine-to-human IAV transmissions occurred rarely and mainly sporadically as compared to avian-to-human spill-over events of avian IAV. Yet, new swIAV variants that harbor zoonotic components continue to be detected. This increases the risk that such components might eventually reassort into viruses with pandemic potential.

Conclusions

Domestic pig populations should not be globally stigmatized as the only or most important reservoir of potentially zoonotic IAV. The likely emergence from swine of the most recent human IAV pandemic in 2009, however, emphasized the principal risks of swine populations in which IAV circulate unimpededly. Implementation of regular and close-meshed IAV surveillance of domestic swine populations to follow the dynamics of swIAV evolution is clearly demanded. Improved algorithms for directly inferring zoonotic potential from whole IAV genome sequences as well as improved vaccines are still being sought.

Efficacy of single-dose and double-dose ivermectin early treatment in preventing progression to hospitalization in mild COVID-19: A multi-arm, parallel-group randomized, double-blind, placebo-controlled trial

Background and objective

Ivermectin is a known anti‐parasitic agent that has been investigated as an antiviral agent against coronavirus disease 2019 (COVID‐19). This study aimed to evaluate the efficacy of ivermectin in mild COVID‐19 patients.

Methods

In this multi‐arm randomized clinical trial conducted between 9 April 2021 and 20 May 2021, a total of 393 patients with reverse transcription‐PCR‐confirmed COVID‐19 infection and mild symptoms were enrolled. Subjects were randomized in a 1:1:1 ratio to receive single‐dose ivermectin (12 mg), double‐dose ivermectin (24 mg) or placebo. The primary outcome was need for hospitalization.

Results

There was no significant difference in the proportion of subjects who required hospitalization between the placebo and single‐dose ivermectin groups (absolute difference in the proportions: −2.3 [95% CI = −8.5, 4.1]) and between the placebo and double‐dose ivermectin groups (absolute difference in the proportions: −3.9 [95% CI = −9.8, 2.2]). The odds of differences in mean change in severity score between single‐dose ivermectin and placebo groups (OR_difference = 1.005 [95% CI: 0.972, 1.040]; p = 0.762) and double‐dose ivermectin and placebo groups (OR_difference = 1.010 [95% CI: 0.974, 1.046]; p = 0.598) were not statistically significant. None of the six adverse events (including mild dermatitis, tachycardia and hypertension) were serious and required extra action.

Conclusion

Single‐dose and double‐dose ivermectin early treatment were not superior to the placebo in preventing progression to hospitalization and improving clinical course in mild COVID‐19.

We conducted a double‐blinded randomized placebo‐controlled trial including 393 patients with mild coronavirus disease 2019 (COVID‐19) and found that ivermectin, an anti‐parasitic medication with known antiviral properties, was non‐superior to the placebo. Neither a single nor a double dose was better in preventing progression to hospitalization and worsening of the clinical course of COVID‐19 infection.

Ivermectin for preventing and treating COVID-19

BACKGROUND

Ivermectin, an antiparasitic agent, inhibits the replication of viruses in vitro. The molecular hypothesis of ivermectin's antiviral mode of action suggests an inhibitory effect on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication in early stages of infection. Currently, evidence on ivermectin for prevention of SARS-CoV-2 infection and COVID-19 treatment is conflicting.

OBJECTIVES

To assess the efficacy and safety of ivermectin plus standard of care compared to standard of care plus/minus placebo, or any other proven intervention for people with COVID-19 receiving treatment as inpatients or outpatients, and for prevention of an infection with SARS-CoV-2 (postexposure prophylaxis).

SEARCH METHODS

We searched the Cochrane COVID-19 Study Register, Web of Science (Emerging Citation Index and Science Citation Index), WHO COVID-19 Global literature on coronavirus disease, and HTA database weekly to identify completed and ongoing trials without language restrictions to 16 December 2021. Additionally, we included trials with > 1000 participants up to April 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing ivermectin to standard of care, placebo, or another proven intervention for treatment of people with confirmed COVID-19 diagnosis, irrespective of disease severity or treatment setting, and for prevention of SARS-CoV-2 infection. Co-interventions had to be the same in both study arms.  For this review update, we reappraised eligible trials for research integrity: only RCTs prospectively registered in a trial registry according to WHO guidelines for clinical trial registration were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We assessed RCTs for bias, using the Cochrane RoB 2 tool. We used GRADE to rate the certainty of evidence for outcomes in the following settings and populations: 1) to treat inpatients with moderate-to-severe COVID-19, 2) to treat outpatients with mild COVID-19 (outcomes: mortality, clinical worsening or improvement, (serious) adverse events, quality of life, and viral clearance), and 3) to prevent SARS-CoV-2 infection (outcomes: SARS-CoV-2 infection, development of COVID-19 symptoms, admission to hospital, mortality, adverse events and quality of life).

MAIN RESULTS

We excluded seven of the 14 trials included in the previous review version; six were not prospectively registered and one was non-randomized. This updated review includes 11 trials with 3409 participants investigating ivermectin plus standard of care compared to standard of care plus/minus placebo. No trial investigated ivermectin for prevention of infection or compared ivermectin to an intervention with proven efficacy. Five trials treated participants with moderate COVID-19 (inpatient settings); six treated mild COVID-19 (outpatient settings). Eight trials were double-blind and placebo-controlled, and three were open-label. We assessed around 50% of the trial results as low risk of bias. We identified 31 ongoing trials. In addition, there are 28 potentially eligible trials without publication of results, or with disparities in the reporting of the methods and results, held in 'awaiting classification' until the trial authors clarify questions upon request. Ivermectin for treating COVID-19 in inpatient settings with moderate-to-severe disease We are uncertain whether ivermectin plus standard of care compared to standard of care plus/minus placebo reduces or increases all-cause mortality at 28 days (risk ratio (RR) 0.60, 95% confidence interval (CI) 0.14 to 2.51; 3 trials, 230 participants; very low-certainty evidence); or clinical worsening, assessed by participants with new need for invasive mechanical ventilation or death at day 28 (RR 0.82, 95% CI 0.33 to 2.04; 2 trials, 118 participants; very low-certainty evidence); or serious adverse events during the trial period (RR 1.55, 95% CI 0.07 to 35.89; 2 trials, 197 participants; very low-certainty evidence). Ivermectin plus standard of care compared to standard of care plus placebo may have little or no effect on clinical improvement, assessed by the number of participants discharged alive at day 28 (RR 1.03, 95% CI 0.78 to 1.35; 1 trial, 73 participants; low-certainty evidence); on any adverse events during the trial period (RR 1.04, 95% CI 0.61 to 1.79; 3 trials, 228 participants; low-certainty evidence); and on viral clearance at 7 days (RR 1.12, 95% CI 0.80 to 1.58; 3 trials, 231 participants; low-certainty evidence). No trial investigated quality of life at any time point. Ivermectin for treating COVID-19 in outpatient settings with asymptomatic or mild disease Ivermectin plus standard of care compared to standard of care plus/minus placebo probably has little or no effect on all-cause mortality at day 28 (RR 0.77, 95% CI 0.47 to 1.25; 6 trials, 2860 participants; moderate-certainty evidence) and little or no effect on quality of life, measured with the PROMIS Global-10 scale (physical component mean difference (MD) 0.00, 95% CI -0.98 to 0.98; and mental component MD 0.00, 95% CI -1.08 to 1.08; 1358 participants; high-certainty evidence). Ivermectin may have little or no effect on clinical worsening, assessed by admission to hospital or death within 28 days (RR 1.09, 95% CI 0.20 to 6.02; 2 trials, 590 participants; low-certainty evidence); on clinical improvement, assessed by the number of participants with all initial symptoms resolved up to 14 days (RR 0.90, 95% CI 0.60 to 1.36; 2 trials, 478 participants; low-certainty evidence); on serious adverse events (RR 2.27, 95% CI 0.62 to 8.31; 5 trials, 1502 participants; low-certainty evidence); on any adverse events during the trial period (RR 1.24, 95% CI 0.87 to 1.76; 5 trials, 1502 participants; low-certainty evidence); and on viral clearance at day 7 compared to placebo (RR 1.01, 95% CI 0.69 to 1.48; 2 trials, 331 participants; low-certainty evidence). None of the trials reporting duration of symptoms were eligible for meta-analysis.

AUTHORS' CONCLUSIONS

For outpatients, there is currently low- to high-certainty evidence that ivermectin has no beneficial effect for people with COVID-19. Based on the very low-certainty evidence for inpatients, we are still uncertain whether ivermectin prevents death or clinical worsening or increases serious adverse events, while there is low-certainty evidence that it has no beneficial effect regarding clinical improvement, viral clearance and adverse events. No evidence is available on ivermectin to prevent SARS-CoV-2 infection. In this update, certainty of evidence increased through higher quality trials including more participants. According to this review's living approach, we will continually update our search.

Synergistic anti-SARS-CoV-2 activity of repurposed anti-parasitic drug combinations

BACKGROUND

COVID-19 pandemic has claimed millions of lives and devastated the health service system, livelihood, and economy in many countries worldwide. Despite the vaccination programs in many countries, the spread of the pandemic continues, and effective treatment is still urgently needed. Although some antiviral drugs have been shown to be effective, they are not widely available. Repurposing of anti-parasitic drugs with in vitro anti-SARS-CoV-2 activity is a promising approach being tested in many clinical trials. Combination of these drugs is a plausible way to enhance their effectiveness.

METHODS

The in vitro anti-SARS-CoV-2 activity of combinations of niclosamide, ivermectin and chloroquine were evaluated in Vero E6 and lung epithelial cells, Calu-3.

RESULTS

All the two-drug combinations showed higher potency resulting in up to 4-fold reduction in the half maximal inhibitory concentration (IC₅₀) values compared to individual drugs. Among these combinations, niclosamide-ivermectin achieved the highest inhibitory level of over 99%. Combination synergy analysis showed niclosamide-ivermectin combination to have the best synergy score with a mean Loewe synergy score of 4.28 and a peak synergy score of 24.6 in Vero E6 cells and a mean Loewe synergy score of 3.82 and a peak synergy score of 10.86 in Calu-3 cells.

CONCLUSIONS

The present study demonstrated the benefit of drug combinations on anti-SARS-CoV-2 activity. Niclosamide and ivermectin showed the best synergistic profile and should be further tested in clinical trials.

Ivermectin under scrutiny: a systematic review and meta-analysis of efficacy and possible sources of controversies in COVID-19 patients

BACKGROUND

We conducted a systematic review and meta-analysis to evaluate the efficacy of ivermectin for COVID-19 patients based on current peer-reviewed RCTs and to address disputes over the existing evidence.

METHODS

MEDLINE (Pubmed), Scopus, Web of Science, Cochrane library, Google scholar and Clinicaltrials.gov were searched for RCTs assessing the efficacy of Ivermectin up to 20 February 2022. A systematic review and meta-analysis of studies was performed based on the PRISMA 2020 statement criteria.

RESULTS

19 and 17 studies were included in this systematic review and meta-analysis, respectively. There was no significant difference in progression to severe disease (log OR - 0.27 [95% CI - 0.61 to 0.08], I2 = 42.29%), negative RT-PCR (log OR 0.25 [95% CI - 0.18-0.68], I2 = 58.73%), recovery (log OR 0.11 [95% CI - 0.22-0.45], I2 = 13.84%), duration of hospitalization (SMD - 0.40 [95% CI - 0.85-0.06], I2 = 88.90%), time to negative RT-PCR (SMD - 0.36 [95% CI - 0.89-0.17], I2 = 46.2%), and viral load (SMD -0.17 [95% CI -0.45 to 0.12], I^2 = 0%). It is worth noting that, based on low-certainty evidence, ivermectin may possibly reduce mortality (log OR - 0.67 [95% CI - 1.20 to - 0.13], I2 = 28.96%). However, studies with a higher risk of bias were more likely to indicate positive effects on the efficacy of this drug, according to our subgroup analyses based on study quality.

CONCLUSION

Ivermectin did not have any significant effect on outcomes of COVID-19 patients and as WHO recommends, use of ivermectin should be limited to clinical trials.

<em>In silico</em> identification of ivermectin as an influenza A virus nuclear export protein inhibitor

Influenza A virus (IAV) is an etiological agent infecting animals and humans that is responsible for seasonal epidemics and devastating pandemics. IAV nuclear export protein (NEP) is a multifaceted protein that plays a pivotal role in the virus life cycle. One of the most important functions of IAV NEP is to transport newly synthesized viral ribonucleoproteins from the nucleus to the cytoplasm. This function is achieved by the interaction between NEP and matrix protein 1 (M1) facilitated by Trp78 surrounded by negatively charged Glu residues in the M1 binding domain of NEP. In the present study, we targeted the IAV NEP with ivermectin. Utilizing in silico molecular docking, we tested ivermectin for its ability to bind NEP. We found that ivermectin strongly binds to NEP with an affinity of –7.3 kcal/mol. The ivermectin binding site identified in this study is located in the NEP-M1 protein interaction region. It is anticipated that blocking NEP-M1 protein interaction can have a considerably deleterious effect on IAV assembly and propagation. This study highlights the possibility of exploring ivermectin as a potential IAV NEP protein blocker, which could be an important therapeutic strategy in the treatment of influenza.

Evolutionary Landscapes of Host-Virus Arms Races

Vertebrate immune systems suppress viral infection using both innate restriction factors and adaptive immunity. Viruses mutate to escape these defenses, driving hosts to counterevolve to regain fitness. This cycle recurs repeatedly, resulting in an evolutionary arms race whose outcome depends on the pace and likelihood of adaptation by host and viral genes. Although viruses evolve faster than their vertebrate hosts, their proteins are subject to numerous functional constraints that impact the probability of adaptation. These constraints are globally defined by evolutionary landscapes, which describe the fitness and adaptive potential of all possible mutations. We review deep mutational scanning experiments mapping the evolutionary landscapes of both host and viral proteins engaged in arms races. For restriction factors and some broadly neutralizing antibodies, landscapes favor the host, which may help to level the evolutionary playing field against rapidly evolving viruses. We discuss the biophysical underpinnings of these landscapes and their therapeutic implications.

Can anti-parasitic drugs help control COVID-19?

Novel COVID-19 is a public health emergency that poses a serious threat to people worldwide. Given the virus spreading so quickly, novel antiviral medications are desperately needed. Repurposing existing drugs is the first strategy. Anti-parasitic drugs were among the first to be considered as a potential treatment option for this disease. Even though many papers have discussed the efficacy of various anti-parasitic drugs in treating COVID-19 separately, so far, no single study comprehensively discussed these drugs. This study reviews some anti-parasitic recommended drugs to treat COVID-19, in terms of function and in vitro as well as clinical results. Finally, we briefly review the advanced techniques, such as artificial intelligence, that have been used to find effective drugs for the treatment of COVID-19.

Prospective mode of action of Ivermectin: SARS-CoV-2

The well-known anti-helminthic drug ivermectin (IVM) has been established as an example of drug repurposing for the management of SARS-CoV-2 infection. Various study has been done to understand the inhibitory mechanism of IVM against SARS-CoV-2 targets. Broadly, IVM has been categorized as a host-directed agent and the proposed mechanism involves inhibition of the IMPα/ß1-mediated nuclear import of viral proteins. In addition, in vitro/in vivo and molecular docking/dynamic simulation studies suggested multitargets mechanism of IVM against SARS-CoV-2. Present manuscript attempts to provide an overview of the detailed mechanism of action based on experimental and computational studies. The knowledge of binding interaction of IVM and SARS-CoV-2 targets will give the direction to developed new and potential anti-COVID agents.

Evaluation of ivermectin antiviral activity against avian infectious bronchitis virus using a chicken embryo model

Ivermectin is widely used in both animals and humans as an FDA-approved parasiticide. Ivermectin has also been reported to have antiviral activity against several viruses including coronaviruses. There are reports that indicate ivermectin may have some role in diminishing the disease caused by SARS-CoV-2, but the evidence is inconclusive. The objective of this study was to determine if ivermectin was efficacious in inhibiting avian infectious bronchitis virus (IBV, a coronavirus) replication in chicken embryos. Briefly, our approach was to use the Massachusetts vaccine strain of IBV in combination with various doses of ivermectin and then inoculate these preparations into chicken embryos to determine if IBV replication was inhibited. The embryos were examined for IBV lesions and samples of chorioallantoic fluid were collected for IBV RT-PCR analysis. Several trials were performed, and the results of our study indicate that ivermectin did not inhibit IBV replication in chicken embryos.

RUNX1 inhibits the antiviral immune response against influenza A virus through attenuating type I interferon signaling

Background

Influenza A viruses (IAVs) are zoonotic, segmented negative-stranded RNA viruses. The rapid mutation of IAVs results in host immune response escape and antiviral drug and vaccine resistance. RUNX1 is a transcription factor that not only plays essential roles in hematopoiesis, but also functions as a regulator in inflammation. However, its role in the innate immunity to IAV infection has not been well studied.

Methods

To investigate the effects of RUNX1 on IAV infection and explore the mechanisms that RUNX1 uses during IAV infection. We infected the human alveolar epithelial cell line (A549) with influenza virus A/Puerto Rico/8/34 (H1N1) (PR8) and examined RUNX1 expression by Western blot and qRT-PCR. We also knocked down or overexpressed RUNX1 in A549 cells, then evaluated viral replication by Western blot, qRT-PCR, and viral titration.

Results

We found RUNX1 expression is induced by IAV H1N1 PR8 infection, but not by poly(I:C) treatment, in the human alveolar epithelial cell line A549. Knockdown of RUNX1 significantly inhibited IAV infection. Conversely, overexpression of RUNX1 efficiently promoted production of progeny viruses. Additionally, RUNX1 knockdown increased IFN-β and ISGs production while RUNX1 overexpression compromised IFN-β and ISGs production upon PR8 infection in A549 cells. We further showed that RUNX1 may attenuate the interferon signaling transduction by hampering the expression of IRF3 and STAT1 during IAV infection.

Conclusions

Taken together, we found RUNX1 attenuates type I interferon signaling to facilitate IAV infection in A549 cells.

Ivermectin and outcomes from Covid‐19 pneumonia: A systematic review and meta‐analysis of randomized clinical trial studies

Ivermectin is an FDA‐approved drug for a parasitic disease that has broad antiviral activity. This study aims to analyse the efficacy of ivermectin in improving the Covid‐19 outcomes. We systematically searched the PubMed, Europe PMC and ClinicalTrials.gov database using specific keywords related to our aims until 10th May 2021. All published randomized clinical trial studies on Covid‐19 and ivermectin were retrieved. The quality of the study was assessed using Jadad scale assessment tool for clinical trial studies. Statistical analysis was done using Review Manager 5.4 software. A total of 19 studies with 2768 Covid‐19 patients were included in this meta‐analysis. This meta‐analysis showed that ivermectin was associated with reduction in severity of Covid‐19 (RR 0.43 [95% CI 0.23–0.81], p = 0.008), reduction of mortality (RR 0.31 [95% CI 0.15–0.62], p = 0.001), higher negative RT‐PCR test results rate (RR 1.23 [95% CI 1.01–1.51], p = 0.04), shorter time to negative RT‐PCR test results (mean difference [MD] −3.29 [95% CI −5.69, −0.89], p = 0.007), higher symptoms alleviations rate (RR 1.23 [95% CI 1.03−1.46], p = 0.02), shorter time to symptoms alleviations (MD −0.68 [95% CI −1.07, −0.29], p = 0.0007) and shorter time to hospital discharge (MD −2.66 [95% CI −4.49, −0.82], p = 0.004). Our study suggests that ivermectin may offer beneficial effects towards Covid‐19 outcomes. More randomized clinical trial studies are still needed to confirm the results of our study.

Could the COVID-19-Driven Increased Use of Ivermectin Lead to Incidents of Imbalanced Gut Microbiota and Dysbiosis?

The microfilaricidal anthelmintic drug ivermectin (IVM) has been used since 1988 for treatment of parasitic infections in animals and humans. The discovery of IVM’s ability to inactivate the eukaryotic importin α/β1 heterodimer (IMPα/β1), used by some viruses to enter the nucleus of susceptible hosts, led to the suggestion of using the drug to combat SARS-CoV-2 infection. Since IVM has antibacterial properties, prolonged use may affect commensal gut microbiota. In this review, we investigate the antimicrobial properties of IVM, possible mode of activity, and the concern that treatment of individuals diagnosed with COVID-19 may lead to dysbiosis.

Repurposing of the approved small molecule drugs in order to inhibit SARS-CoV-2 S protein and human ACE2 interaction through virtual screening approaches

Most recently, the new coronavirus (SARS-CoV-2) has been recognized as a pandemic by the World Health Organization (WHO) while this virus shares substantial similarity with SARS-CoV. So far, no definitive vaccine or drug has been developed to cure Covid-19 disease, since many important aspects about Covid-19 such as pathogenesis and proliferation pathways are still unclear. It was proven that human ACE2 is the main receptor for the entry of Covid-19 into lower respiratory tract epithelial cells through interaction with SARS-CoV-2 S protein. Based on this observation, it is expected that the virus infection can be inhibited if protein-protein interaction is prevented. In this study, using structure-based virtual screening of FDA databases, several lead drugs were discovered based on the ACE2-binding pocket of SARS-CoV-2 S protein. Then, binding affinity, binding modes, critical interactions, and pharmaceutical properties of the lead drugs were evaluated. Among the previously approved drugs, Diammonium Glycyrrhizinate, Digitoxin, Ivermectin, Rapamycin, Rifaximin, and Amphotericin B represented the most desirable features, and can be possible candidates for Covid-19 therapies. Furthermore, molecular dynamics (MD) simulation was accomplished for three S protein/drug complexes with the highest binding affinity and best conformation and binding free energies were also computed with the Molecular Mechanics/Poisson-Boltzmann Surface Area (MM/PBSA) method. Results demonstrated the stable binding of these compounds to the S protein; however, in order to confirm the curative effect of these drugs, clinical trials must be done.

Chemoprophylaxis against COVID-19 among health-care workers using Ivermectin in low- and middle-income countries: A systematic review and meta-analysis

Coronavirus disease-2019 (COVID-19) is a novel viral infectious disease that the World Health Organization (WHO) has announced to be a pandemic. This meta-analysis was aimed at providing evidence for the use of ivermectin to prevent COVID-19 among hospital workers in low-resource countries. Medical databases including African Journals online, Google Scholar, PubMed, Cochrane library, EMBASE, COVID-19 research database (WHO), Clinicaltrials.gov, and SCOPUS were searched for studies on Ivermectin as a chemoprophylactic drug against COVID-19 among hospital personnel in settings with limited resources. Preprint servers such as bioRxiv and medRxiv as well as the gray literature were also searched. Studies adjudged to be eligible were identified using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses algorithm. Statistical analyses were done using Stata version 14.3. Seven studies were selected for the meta-analysis. The total sample size was 2652. There were two randomized controlled trials and five nonrandomized studies. Some studies dosed Ivermectin daily while some dosed it weekly. However, one of the studies dosed it monthly. The studies reported variable clinical benefits. I² statistic was 92%, and random effect model was used. The pooled odd ratio was 0.11 (95% confidence interval 0.09–0.13). This implies that 89% of the participants benefited from taking Ivermectin as a form of preexposure chemoprophylaxis. Ivermectin has a significant clinical benefit as a preventive drug against COVID-19 for hospital personnel in settings with limited resources.

In-line treatments and clinical initiatives to fight against COVID-19 outbreak

In December 2019, when the whole world is waiting for Christmas and New Year, the physicians of Wuhan, China, are astounded by clusters of patients suffering from pneumonia from unknown causes. The pathogen isolated from the respiratory epithelium of the patients is similar to previously known coronaviruses with some distinct features. The disease was initially called nCoV-2019 or SARS-nCoV-2 and later termed as COVID-19 by WHO. The infection is rapidly propagating from the day of emergence, spread throughout the globe and now became a pandemic which challenged the competencies of developed nations in terms of health care management. As per WHO report, 216 countries are affected with SARS-CoV-19 by August 5, 2020 with 18, 142, 718 confirmed cases and 691,013 deaths reports. Such huge mortality and morbidity rates are truly threatening and calls for some aggressive and effective measures to slow down the disease transmission. The scientists are constantly engaged in finding a potential solution to diagnose and treat the pandemic. Various FDA approved drugs with the previous history of antiviral potency are repurposed for COVID-19 treatment. Different drugs and vaccines are under clinical trials and some rapid and effective diagnostic tools are also under development. In this review, we have highlighted the current epidemiology through infographics, disease transmission and progression, clinical features and diagnosis and possible therapeutic approaches for COVID-19. The article mainly focused on the development and possible application of various FDA approved drugs, including chloroquine, remdesivir, favipiravir, nefamostate mesylate, penciclovir, nitazoxanide, ribavirin etc., vaccines under development and various registered clinical trials exploring different therapeutic measures for the treatment of COVID-19. This information will definitely help the researchers to understand the in-line scientific progress by various clinical agencies and regulatory bodies against COVID-19.

COVID-19 Pandemic: Outbreak, Potential Vaccines And Medications

The outbreak of the current global pandemic caused by the spread of a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has posed an unprecedented threat to global health and economy across the whole world. As of today, the number of cases diagnosed with SARS-CoV-2 is exceeding 271 million with over 5.32 million deaths globally. Despite the high throughput technology and considerable advances in sciences, the outbreaks of the COVID-19 pandemic present a colossal challenge to scientific community. Scientists and clinicians all over the world are putting tremendous efforts to develop effective treatments to combat this deadly pathogen, at least to contain it momentarily until an adequate treatment regimen is available. Conventionally, vaccines have been developed as one of the therapeutic strategies to restrict infectious diseases. Although several vaccines are in the pipeline, evaluation of efficacy in animals’ studies and human are time-consuming. On the other hand, several drugs already in clinical use are being employed to test their efficacy against SARS-CoV-2. Some of these drugs have been already used as anti-viral drugs and others have been used for different therapeutic purposes. In this review, we summarize the ongoing efforts to control the dissemination of SARS-CoV-2 and highlight the potential prophylactic and therapeutic measures including the recently developed vaccines in the foreseeable future. Moreover, we emphasize an importance of having a customized strategy that can be easily and quickly employed to overcome possible future outbreaks.

Multipurpose Drugs Active Against Both Plasmodium spp. and Microorganisms: Potential Application for New Drug Development

Malaria, a disease caused by the protozoan parasites Plasmodium spp., is still causing serious problems in endemic regions in the world. Although the WHO recommends artemisinin combination therapies for the treatment of malaria patients, the emergence of artemisinin-resistant parasites has become a serious issue and underscores the need for the development of new antimalarial drugs. On the other hand, new and re-emergences of infectious diseases, such as the influenza pandemic, Ebola virus disease, and COVID-19, are urging the world to develop effective chemotherapeutic agents against the causative viruses, which are not achieved to the desired level yet. In this review article, we describe existing drugs which are active against both Plasmodium spp. and microorganisms including viruses, bacteria, and fungi. We also focus on the current knowledge about the mechanism of actions of these drugs. Our major aims of this article are to describe examples of drugs that kill both Plasmodium parasites and other microbes and to provide valuable information to help find new ideas for developing novel drugs, rather than merely augmenting already existing drug repurposing efforts.

SARS-COV-2, infection, transmission, transcription, translation, proteins, and treatment: A review

In this review, we describe the key molecular entities involved in the process of infection by SARS-CoV-2, while also detailing how those key entities influence the spread of the disease. We further introduce the molecular mechanisms of preventive and treatment strategies including drugs, antibodies, and vaccines.

COVID-19: A review of newly formed viral clades, pathophysiology, therapeutic strategies and current vaccination tasks

Today, the world population is facing an existential threat by an invisible enemy known as severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) or COVID-19. It is highly contagious and has infected a larger fraction of human population across the globe on various routes of transmission. The detailed knowledge of the SARS-CoV-2 structure and clinical aspects offers an important insight into the evolution of infection, disease progression and helps in executing the different therapies effectively. Herein, we have discussed in detail about the genome structure of SARS-CoV-2 and its role in the proteomic rational spread of different muted species and pathogenesis in infecting the host cells. The mechanisms behind the viral outbreak and its immune response, the availability of existing diagnostics techniques, the treatment efficacy of repurposed drugs and the emerging vaccine trials for the SARS-CoV-2 outbreak also have been highlighted. Furthermore, the possible antiviral effects of various herbal products and their extracted molecules in inhibiting SARS-CoV-2 replication and cellular entry are also reported. Finally, we conclude our opinion on current challenges involved in the drug development, bulk production of drug/vaccines and their storage requirements, logistical procedures and limitations related to dosage trials for larger population.

Treatment of SARS-CoV-2 (COVID-19): A safety perspective

The goal of this review is to report a balanced perspective of current evidence for efficacy of treatments for coronavirus disease 2019 (COVID-19) against the historical safety of these treatments as of May 2021. We preselected therapies of interest for COVID-19 based on national guidelines and modified over time. We searched PubMed and Medline for these specific COVID-19 treatments and data related to their efficacy. We also searched for prior randomized controlled trials of each therapy to assess adverse effects, and we obtained the Food and Drug Administration Approval label for this information. Several drugs have been approved for the treatment of COVID-19, and many more are under study. This includes dexamethasone, remdesivir, hydroxychloroquine/chloroquine, lopinvir/ritonavir, interferon or interleukin inhibitors, convalescent plasma and several vitamins and minerals. The strongest evidence for benefit is mortality benefit with dexamethasone in patients with COVID-19 and hypoxemia, although there is a signal of harm if this is started too early. There are several other promising therapies, like interleukin inhibitors and ivermectin. Hydroxychloroquine/chloroquine, lopinvir/ritonavir, and convalescent plasma do not have enough evidence of benefit to outweigh the known risks of these drugs.

Ivermectin for preventing and treating COVID-19

BACKGROUND

Ivermectin, an antiparasitic agent used to treat parasitic infestations, inhibits the replication of viruses in vitro. The molecular hypothesis of ivermectin's antiviral mode of action suggests an inhibitory effect on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication in the early stages of infection. Currently, evidence on efficacy and safety of ivermectin for prevention of SARS-CoV-2 infection and COVID-19 treatment is conflicting.

OBJECTIVES

To assess the efficacy and safety of ivermectin compared to no treatment, standard of care, placebo, or any other proven intervention for people with COVID-19 receiving treatment as inpatients or outpatients, and for prevention of an infection with SARS-CoV-2 (postexposure prophylaxis).

SEARCH METHODS

We searched the Cochrane COVID-19 Study Register, Web of Science (Emerging Citation Index and Science Citation Index), medRxiv, and Research Square, identifying completed and ongoing studies without language restrictions to 26 May 2021.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing ivermectin to no treatment, standard of care, placebo, or another proven intervention for treatment of people with confirmed COVID-19 diagnosis, irrespective of disease severity, treated in inpatient or outpatient settings, and for prevention of SARS-CoV-2 infection. Co-interventions had to be the same in both study arms.  We excluded studies comparing ivermectin to other pharmacological interventions with unproven efficacy.

DATA COLLECTION AND ANALYSIS

We assessed RCTs for bias, using the Cochrane risk of bias 2 tool. The primary analysis excluded studies with high risk of bias. We used GRADE to rate the certainty of evidence for the following outcomes 1. to treat inpatients with moderate-to-severe COVID-19: mortality, clinical worsening or improvement, adverse events, quality of life, duration of hospitalization, and viral clearance; 2. to treat outpatients with mild COVID-19: mortality, clinical worsening or improvement, admission to hospital, adverse events, quality of life, and viral clearance; (3) to prevent SARS-CoV-2 infection: SARS-CoV-2 infection, development of COVID-19 symptoms, adverse events, mortality, admission to hospital, and quality of life.

MAIN RESULTS

We found 14 studies with 1678 participants investigating ivermectin compared to no treatment, placebo, or standard of care. No study compared ivermectin to an intervention with proven efficacy. There were nine studies treating participants with moderate COVID-19 in inpatient settings and four treating mild COVID-19 cases in outpatient settings. One study investigated ivermectin for prevention of SARS-CoV-2 infection. Eight studies had an open-label design, six were double-blind and placebo-controlled. Of the 41 study results contributed by included studies, about one third were at overall high risk of bias.  Ivermectin doses and treatment duration varied among included studies.  We identified 31 ongoing and 18 studies awaiting classification until publication of results or clarification of inconsistencies. Ivermectin compared to placebo or standard of care for inpatient COVID-19 treatment We are uncertain whether ivermectin compared to placebo or standard of care reduces or increases mortality (risk ratio (RR) 0.60, 95% confidence interval (CI) 0.14 to 2.51; 2 studies, 185 participants; very low-certainty evidence) and clinical worsening up to day 28 assessed as need for invasive mechanical ventilation (IMV) (RR 0.55, 95% CI 0.11 to 2.59; 2 studies, 185 participants; very low-certainty evidence) or need for supplemental oxygen (0 participants required supplemental oxygen; 1 study, 45 participants; very low-certainty evidence), adverse events within 28 days (RR 1.21, 95% CI 0.50 to 2.97; 1 study, 152 participants; very low-certainty evidence), and viral clearance at day seven (RR 1.82, 95% CI 0.51 to 6.48; 2 studies, 159 participants; very low-certainty evidence). Ivermectin may have little or no effect compared to placebo or standard of care on clinical improvement up to 28 days (RR 1.03, 95% CI 0.78 to 1.35; 1 study; 73 participants; low-certainty evidence) and duration of hospitalization (mean difference (MD) -0.10 days, 95% CI -2.43 to 2.23; 1 study; 45 participants; low-certainty evidence). No study reported quality of life up to 28 days. Ivermectin compared to placebo or standard of care for outpatient COVID-19 treatment We are uncertain whether ivermectin compared to placebo or standard of care reduces or increases mortality up to 28 days (RR 0.33, 95% CI 0.01 to 8.05; 2 studies, 422 participants; very low-certainty evidence) and clinical worsening up to 14 days assessed as need for IMV (RR 2.97, 95% CI 0.12 to 72.47; 1 study, 398 participants; very low-certainty evidence) or non-IMV or high flow oxygen requirement (0 participants required non-IMV or high flow; 1 study, 398 participants; very low-certainty evidence). We are uncertain whether ivermectin compared to placebo reduces or increases viral clearance at seven days (RR 3.00, 95% CI 0.13 to 67.06; 1 study, 24 participants; low-certainty evidence). Ivermectin may have little or no effect compared to placebo or standard of care on the number of participants with symptoms resolved up to 14 days (RR 1.04, 95% CI 0.89 to 1.21; 1 study, 398 participants; low-certainty evidence) and adverse events within 28 days (RR 0.95, 95% CI 0.86 to 1.05; 2 studies, 422 participants; low-certainty evidence). None of the studies reporting duration of symptoms were eligible for primary analysis. No study reported hospital admission or quality of life up to 14 days. Ivermectin compared to no treatment for prevention of SARS-CoV-2 infection We found one study. Mortality up to 28 days was the only outcome eligible for primary analysis. We are uncertain whether ivermectin reduces or increases mortality compared to no treatment (0 participants died; 1 study, 304 participants; very low-certainty evidence). The study reported results for development of COVID-19 symptoms and adverse events up to 14 days that were included in a secondary analysis due to high risk of bias. No study reported SARS-CoV-2 infection, hospital admission, and quality of life up to 14 days.

AUTHORS' CONCLUSIONS

Based on the current very low- to low-certainty evidence, we are uncertain about the efficacy and safety of ivermectin used to treat or prevent COVID-19. The completed studies are small and few are considered high quality. Several studies are underway that may produce clearer answers in review updates. Overall, the reliable evidence available does not support the use ivermectin for treatment or prevention of COVID-19 outside of well-designed randomized trials.

COVID-19: Failure of the DisCoVeRy Clinical Trial, and Now-New Hopes?

The DisCoVeRy clinical trial aimed at the evaluation of four treatments for patients suffering from severe to critical COVID-19: Hydroxychloroquine, eventually associated with azithromycin; the combination lopinavir/ritonavir; the combination with the addition of interferon β-1a; remdesivir. The trial was discontinued due to the lack of positive results. Meanwhile, many other potential options have been considered either to target the virus itself, the interactions with the host cells, or the cytokine storm frequently observed during the infection. Several of those options are briefly reviewed. They include vaccines, small molecules, antibodies, and stem cells.

Ivermectin to prevent hospitalizations in patients with COVID-19 (IVERCOR-COVID19) a randomized, double-blind, placebo-controlled trial

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) has changed our lives. The scientific community has been investigating re-purposed treatments to prevent disease progression in coronavirus disease (COVID-19) patients.

OBJECTIVE

To determine whether ivermectin treatment can prevent hospitalization in individuals with early COVID-19.

DESIGN, SETTING AND PARTICIPANTS

A randomized, double-blind, placebo-controlled study was conducted in non-hospitalized individuals with COVID-19 in Corrientes, Argentina. Patients with SARS-CoV-2 positive nasal swabs were contacted within 48 h by telephone to invite them to participate. The trial randomized 501 patients between August 19th 2020 and February 22nd 2021.

INTERVENTION

Patients were randomized to ivermectin (N = 250) or placebo (N = 251) arms in a staggered dose, according to the patient's weight, for 2 days.

MAIN OUTCOMES AND MEASURES

The efficacy of ivermectin to prevent hospitalizations was evaluated as primary outcome. We evaluated secondary outcomes in relationship to safety and other efficacy end points.

RESULTS

The mean age was 42 years (SD ± 15.5) and the median time since symptom onset to the inclusion was 4 days [interquartile range 3-6]. The primary outcome of hospitalization was met in 14/250 (5.6%) individuals in ivermectin group and 21/251 (8.4%) in placebo group (odds ratio 0.65; 95% confidence interval, 0.32-1.31; p = 0.227). Time to hospitalization was not statistically different between groups. The mean time from study enrollment to invasive mechanical ventilatory support (MVS) was 5.25 days (SD ± 1.71) in ivermectin group and 10 days (SD ± 2) in placebo group, (p = 0.019). There were no statistically significant differences in the other secondary outcomes including polymerase chain reaction test negativity and safety outcomes.

LIMITATIONS

Low percentage of hospitalization events, dose of ivermectin and not including only high-risk population.

CONCLUSION

Ivermectin had no significant effect on preventing hospitalization of patients with COVID-19. Patients who received ivermectin required invasive MVS earlier in their treatment. No significant differences were observed in any of the other secondary outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04529525 .

Neurological Effects of Sars-Cov-2 And Neurotoxicity of Antiviral Drugs Against Covid-19

Severe Acute Respiratory Syndrome (SARS) is caused by different SARS viruses. In 2020, novel coronavirus (SARS-CoV-2) led to an ongoing pandemic, known as "Coronavirus Disease 2019 (COVID-19)". The disease can spread among individuals through direct (via saliva, respiratory secretions or secretion droplets) or indirect (through contaminated objects or surfaces) contact. The pandemic has spread rapidly from Asia to Europe and later to America. It continues to affect all parts of the world at an increasing rate. There have been over 92 million confirmed cases of COVID-19 by mid-January 2021. The similarity of homological sequences between SARS-CoV-2 and other SARS-CoVs is high. In addition, clinical symptoms of SARS-CoV-2 and other SARS viruses show similarities. However, some COVID-19 cases show neurologic signs like headache, loss of smell, hiccups and encephalopathy. The drugs used in the palliative treatment of the disease also have some neurotoxic effects. Currently, there are approved vaccines for COVID-19. However, there is a need for specific therapeutics against COVID-19. This review will describe the neurological effects of SARS-CoV-2 and the neurotoxicity of COVID-19 drugs used in clinics. Drugs used in the treatment of COVID-19 will be evaluated by their mechanism of action and their toxicological effects.