Novel Antiviral Strategies in the Treatment of COVID-19: A Review

Challenges and Recent Advancements in COVID-19 Vaccines

Vaccination is the most effective method for the prevention of COVID-19 caused by SARS-CoV-2, which is still a global epidemic. However, the evolution of SARS-CoV-2 is so rapid that various variants, including the Alpha, Beta, Gamma, Delta, and Omicron variants, have emerged, lowering the protection rate of vaccines and even resulting in breakthrough infections. Additionally, some rare but severe adverse reactions induced by COVID-19 vaccines may raise safety concerns and hinder vaccine promotion; however, clinical studies have shown that the benefits of vaccination outweigh the risks caused by adverse reactions. Current vaccines approved with emergency use authorization (EUA) were originally adaptive for adults only, and infants, children, and adolescents are not included. New-generation vaccines are needed to overcome the challenges of limited adaptive age population, breakthrough infection (mainly due to virus variant emergencies), and critical adverse reactions. Fortunately, some advances in COVID-19 vaccines have been obtained regarding enlarged adaptive populations for clinical applications, such as the Pfizer/BioNTech vaccine and the Moderna vaccine. In this article, we provide a review on the challenges and recent advancements in COVID-19 vaccines. The development of next-generation COVID-19 vaccines should lay emphasis on the expansion of adaptive age populations in all individuals, the induction of immune responses to viral variants, the avoidance or alleviation of rare but potentially critical adverse reactions, and the discovery of subunit vaccines with adjuvants encapsulated in nanoparticles.

Analytical approaches for determination of COVID-19 candidate drugs in human biological matrices

Since the outbreak of the COVID-19 pandemic, the use of antiviral and other available drugs has been considered to combat or reduce the clinical symptoms of patients. In this regard, it would be necessary to choose sensitive and selective analytical techniques for pharmacokinetic and pharmacodynamic studies, monitoring of drug concentration in biological fluids, and determination of the most appropriate dose to achieve the desired effect on the disease. In the present study, the analytical techniques based on spectroscopy and chromatography with different detectors for diagnosis and determination of candidate drugs in the treatment of COVID-19 in human biological fluids are reviewed during the period 2015-2022. Moreover, various sample preparation and extraction techniques, are being used for this purpose, such as protein precipitation (PP), solid-phase extraction (SPE), liquid-liquid extraction (LLE), and QuEChERS (quick, easy, cheap, effective, rugged, and safe) are investigated.

Purinergic signaling elements are correlated with coagulation players in peripheral blood and leukocyte samples from COVID-19 patients

For over a year, the coronavirus disease 2019 has been affecting the world population by causing severe tissue injuries and death in infected people. Adenosine triphosphate (ATP) and the nicotinamide adenine dinucleotide (NAD +) are two molecules that are released into the extracellular microenvironment after direct virus infection or cell death caused by hyper inflammation and coagulopathy. Also, these molecules are well known to participate in multiple pathways and have a pivotal role in the purinergic signaling pathway. Thus, using public datasets available on the Gene Expression Omnibus (GEO), we analyzed raw proteomics data acquired using mass spectrometry (the gold standard method) and raw genomics data from COVID-19 patient samples obtained by microarray. The data was analyzed using bioinformatics and statistical methods according to our objectives. Here, we compared the purinergic profile of the total leukocyte population and evaluated the levels of these soluble biomolecules in the blood, and their correlation with coagulation components in COVID-19 patients, in comparison to healthy people or non-COVID-19 patients. The blood metabolite analysis showed a stage-dependent inosine increase in COVID-19 patients, while the nucleotides ATP and ADP had positive correlations with fibrinogen and other coagulation proteins. Also, ATP, ADP, inosine, and hypoxanthine had positive and negative correlations with clinical features. Regarding leukocyte gene expression, COVID-19 patients showed an upregulation of the P2RX1, P2RX4, P2RX5, P2RX7, P2RY1, P2RY12, PANX1, ADORA2B, NLPR3, and F3 genes. Yet, the ectoenzymes of the canonical and non-canonical adenosinergic pathway (ENTPD1 and CD38) are upregulated, suggesting that adenosine is produced by both active adenosinergic pathways. Hence, approaches targeting these biomolecules or their specific purinoreceptors and ectoenzymes may attenuate the high inflammatory state and the coagulopathy seen in COVID-19 patients. KEY MESSAGES : Adenosinergic pathways are modulated on leukocytes from COVID-19 patients. Plasmatic inosine levels are increased in COVID-19 patients. ATP, ADP, AMP, hypoxanthine, and inosine are correlated with coagulation players. The nucleotides and nucleosides are correlated with patients' clinical features. The P2 receptors and ectoenzymes are correlated with Tissue factor in COVID-19.

Challenges to manage pandemic of coronavirus disease (COVID-19) in Iran with a special situation: a qualitative multi-method study

BACKGROUND

With the unprecedented expansion of COVID-19 in the world since December 2019, Iran's health system, like other countries, faced various challenges in managing the disease, which led to numerous experiences and lessons learned. This study was conducted to identify these challenges regarding unique political, economic, and cultural issues, which could help other countries with similar situations.

METHODS

The present study was performed using a qualitative multi-method approach with a content analysis method. The data were collected through in-depth and semi-structured interviews and focused group discussions with 60 key persons who were selected purposefully, including policymakers, health care workers, and affected people by the disease, and the review of all available national reports between February 21, 2020, and March 22, 2021. The data collection and analysis were done simultaneously.

RESULTS

Identified critical challenges for the management of COVID-19 in the health system were limited evidence and scientific controversies, poor social prevention and social inequalities, burnout and sustained workload among healthcare workers, improper management of resources and equipment, the lack of a guideline for contact tracing, and patient flow management, and mental health problems in the community.

CONCLUSIONS

According to our results, measures should be taken to conduct a continuous comprehensive risk assessment and develop a national response plan with an emphasis on precise contact tracing, active screening, patient flow, paying attention to the psychological and social dimensions of the disease, and also transparency of social inequalities in the face of risk factors of the COVID-19. Also, the social protection programs should become a vital tool for policymakers and supporting the vulnerable groups using the capacity of the community and international cooperation to develop a vaccine, which is difficult to procure due to the sanctions.

Perspectives on the use and risk of adverse events associated with cytokine-storm targeting antibodies and challenges associated with development of novel monoclonal antibodies for the treatment of COVID-19 clinical cases

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the novel coronavirus disease 2019 (COVID-19) pandemic that lacks globally accessible effective antivirals or extensively available vaccines. Numerous clinical trials are exploring the applicability of repurposed monoclonal antibodies (mAbs) targeting cytokines that cause adverse COVID-19-related pathologies, and novel mAbs directly targeting SARS-CoV-2. However, comorbidities and the incidence of cytokine storm (CS)-associated pathological complexities in some COVID-19 patients may limit the clinical use of these drugs. Additionally, CS-targeting mAbs have the potential to cause adverse events that restrict their applicability in patients with comorbidities. Novel mAbs targeting SARS-CoV-2 require pharmacological and toxicological characterization before a marketable product becomes available. The affordability of novel mAbs across the global economic spectrum may seriously limit their accessibility. This review presents a perspective on antibody-based research efforts and their limitations for COVID-19.

The three frontlines against COVID-19: Brain, Behavior, and Immunity

The pandemic outbreak of coronavirus disease 2019 (COVID-19) is raising global anxiety and fear of both real and perceived health threat from the virus. Overwhelming evidence shows infected patients experiencing neuropsychiatric complications, suggesting that the "psychoneuroimmunity" model might be beneficial in understanding the impact of the virus. Therefore, this Special Issue on "Immunopsychiatry of COVID-19 Pandemic" was launched immediately after the pandemic was declared, with the first paper accepted on the March 25th, 2020. A total of ninety-three papers were accepted, the last one was on the July 10th, 2020 when the initial acute phase started declining. The papers of this Special Issue have illuminated the social impact, psychopathology, neurological manifestation, immunity responses, and potential treatments and prevention on COVID-19. For example, anxiety disorders, mood disorders, and suicidal ideation are most common psychiatric manifestations. COVID-19 infection can have central and/or peripheral nervous system symptoms, including headache, sleep disorders, encephalopathy, and loss of taste and smell. A "three-steps" Neuro-COVID infection model (neuro-invasion, clearance and immune response) was established. The current therapeutic interventions for COVID-19 include supportive intervention, immunomodulatory agents, antiviral therapy, and plasma transfusion. Psychological support should be implemented, improving the psychological wellbeing, as well as to enhance psychoneuroimmunity against COVID-19.

A Scoping Insight on Potential Prophylactics, Vaccines and Therapeutic Weaponry for the Ongoing Novel Coronavirus (COVID-19) Pandemic- A Comprehensive Review

The emergence of highly virulent CoVs (SARS-CoV-2), the etiologic agent of novel ongoing "COVID-19" pandemics has been marked as an alarming case of pneumonia posing a large global healthcare crisis of unprecedented magnitude. Currently, the COVID-19 outbreak has fueled an international demand in the biomedical field for the mitigation of the fast-spreading illness, all through the urgent deployment of safe, effective, and rational therapeutic strategies along with epidemiological control. Confronted with such contagious respiratory distress, the global population has taken significant steps towards a more robust strategy of containment and quarantine to halt the total number of positive cases but such a strategy can only delay the spread. A substantial number of potential vaccine candidates are undergoing multiple clinical trials to combat COVID-19 disease, includes live-attenuated, inactivated, viral-vectored based, sub-unit vaccines, DNA, mRNA, peptide, adjuvant, plant, and nanoparticle-based vaccines. However, there are no licensed anti-COVID-19 drugs/therapies or vaccines that have proven to work as more effective therapeutic candidates in open-label clinical trial studies. To counteract the infection (SARS-CoV-2), many people are under prolonged treatment of many chemical drugs that inhibit the PLpro activity (Ribavirin), viral proteases (Lopinavir/Ritonavir), RdRp activity (Favipiravir, Remdesivir), viral membrane fusion (Umifenovir, Chloroquine phosphate (CQ), Hydroxychloroquine phosphate (HCQ), IL-6 overexpression (Tocilizumab, Siltuximab, Sarilumab). Mesenchymal Stem Cell therapy and Convalescent Plasma Therapy have emerged as a promising therapeutic strategy against SARS-CoV-2 virion. On the other hand, repurposing previously designed antiviral agents with tolerable safety profile and efficacy could be the only promising approach and fast response to the novel virion. In addition, research institutions and corporations have commenced the redesign of the available therapeutic strategy to manage the global crisis. Herein, we present succinct information on selected anti-COVID-19 therapeutic medications repurposed to combat SARS-CoV-2 infection. Finally, this review will provide exhaustive detail on recent prophylactic strategies and ongoing clinical trials to curb this deadly pandemic, outlining the major therapeutic areas for researchers to step in.

Handheld Point-of-Care System for Rapid Detection of SARS-CoV-2 Extracted RNA in under 20 min

The COVID-19 pandemic is a global health emergency characterized by the high rate of transmission and ongoing increase of cases globally. Rapid point-of-care (PoC) diagnostics to detect the causative virus, SARS-CoV-2, are urgently needed to identify and isolate patients, contain its spread and guide clinical management. In this work, we report the development of a rapid PoC diagnostic test (<20 min) based on reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) and semiconductor technology for the detection of SARS-CoV-2 from extracted RNA samples. The developed LAMP assay was tested on a real-time benchtop instrument (RT-qLAMP) showing a lower limit of detection of 10 RNA copies per reaction. It was validated against extracted RNA from 183 clinical samples including 127 positive samples (screened by the CDC RT-qPCR assay). Results showed 91% sensitivity and 100% specificity when compared to RT-qPCR and average positive detection times of 15.45 ± 4.43 min. For validating the incorporation of the RT-LAMP assay onto our PoC platform (RT-eLAMP), a subset of samples was tested (n = 52), showing average detection times of 12.68 ± 2.56 min for positive samples (n = 34), demonstrating a comparable performance to a benchtop commercial instrument. Paired with a smartphone for results visualization and geolocalization, this portable diagnostic platform with secure cloud connectivity will enable real-time case identification and epidemiological surveillance.

Stem cell therapy for COVID-19, ARDS and pulmonary fibrosis

Coronavirus disease 2019 (COVID-19) is an acute respiratory infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 mainly causes damage to the lung, as well as other organs and systems such as the hearts, the immune system and so on. Although the pathogenesis of COVID-19 has been fully elucidated, there is no specific therapy for the disease at present, and most treatments are limited to supportive care. Stem cell therapy may be a potential treatment for refractory and unmanageable pulmonary illnesses, which has shown some promising results in preclinical studies. In this review, we systematically summarize the pathogenic progression and potential mechanisms underlying stem cell therapy in COVID-19, and registered COVID-19 clinical trials. Of all the stem cell therapies touted for COVID-19 treatment, mesenchymal stem cells (MSCs) or MSC-like derivatives have been the most promising in preclinical studies and clinical trials so far. MSCs have been suggested to ameliorate the cytokine release syndrome (CRS) and protect alveolar epithelial cells by secreting many kinds of factors, demonstrating safety and possible efficacy in COVID-19 patients with acute respiratory distress syndrome (ARDS). However, considering the consistency and uniformity of stem cell quality cannot be quantified nor guaranteed at this point, more work remains to be done in the future.

Hypoxic preconditioning - A nonpharmacological approach in COVID-19 prevention

Hypoxia is defined by low oxygen concentration in organs, tissues, and cells. Maintaining oxygen homeostasis represents the essential cellular metabolic process for the structural integrity of tissues in different pathological conditions, including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Considering the role of hypoxia-inducible factor-1 as the regulator of cellular response to hypoxia and its involvement in angiogenesis, erythropoiesis, glucose metabolism, inflammation, we propose hypoxic preconditioning (HPC) as a novel prevention therapeutic approach on healthy contacts of patients with coronavirus disease-2019 (COVID-19). To date, several studies revealed the beneficial effects of HPC in ischemia, kidney failure, and in pulmonary function recovery of patients who underwent lung surgery. HPC increases the expression of factors that promote cell survival and angiogenesis, induces an anti-inflammatory outcome, triggers coordinated hypoxia responses that promote erythropoiesis, and mobilizes the circulating progenitor cells. Furthermore, the mesenchymal stem cells (MSC) exposed to HPC show improvement of their regenerative capacities and increases the effectiveness of stem cell therapy in different pathologies, including COVID-19. In conclusion, HPC should be considered as an approach with beneficial outcomes and without significant side effects when the organism is severely exposed to the same stressor. HPC appears as a trigger to mechanisms that improve and maintain tissue oxygenation and repair, a main goal in different pathologies, including COVID-19 or other respiratory conditions.

In silico Investigation on the Inhibiting Role of Nicotine/Caffeine by Blocking the S Protein of SARS-CoV-2 Versus ACE2 Receptor

In this paper, we studied the in silico interaction of angiotensin-converting enzyme 2 (ACE2) human receptor with two bioactive compounds, i.e., nicotine and caffeine, via molecular dynamic (MD) simulations. The simulations reveal the efficient blocking of ACE2 by caffeine and nicotine in the exposure to the spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We have selected the two most important active sites of ACE2-S protein, i.e., 6LZG and 6VW1, which are critically responsible in the interaction of S protein to the receptor and thus, we investigated their interaction with nicotine and caffeine through MD simulations. Caffeine and nicotine are interesting structures for interactions because of their similar structure to the candidate antiviral drugs. Our results reveal that caffeine or nicotine in a specific molar ratio to 6LZG shows a very strong interaction and indicate that caffeine is more efficient in the interaction with 6LZG and further blocking of this site against S protein binding. Further, we investigated the interaction of ACE2 receptor- S protein with nicotine or caffeine when mixed with candidate or approved antiviral drugs for SARS-CoV-2 therapy. Our MD simulations suggest that the combination of caffeine with ribavirin shows a stronger interaction with 6VW1, while in case of favipiravir+nicotine, 6LZG shows potent efficacy of these interaction, proposing the potent efficacy of these combinations for blocking ACE2 receptor against SARS-CoV-2.

Vitamin D sufficiency, a serum 25-hydroxyvitamin D at least 30 ng/mL reduced risk for adverse clinical outcomes in patients with COVID-19 infection

BACKGROUND

To investigate the association between serum 25-hydroxyvitamin D levels and its effect on adverse clinical outcomes, and parameters of immune function and mortality due to a SARS-CoV-2 infection.

STUDY DESIGN

The hospital data of 235 patients infected with COVID-19 were analyzed.

RESULTS

Based on CDC criteria, among our study patients, 74% had severe COVID-19 infection and 32.8% were vitamin D sufficient. After adjusting for confounding factors, there was a significant association between vitamin D sufficiency and reduction in clinical severity, inpatient mortality serum levels of C-reactive protein (CRP) and an increase in lymphocyte percentage. Only 9.7% of patients older than 40 years who were vitamin D sufficient succumbed to the infection compared to 20% who had a circulating level of 25(OH)D< 30 ng/ml. The significant reduction in serum CRP, an inflammatory marker, along with increased lymphocytes percentage suggest that vitamin D sufficiency also may help modulate the immune response possibly by reducing risk for cytokine storm in response to this viral infection.

CONCLUSION

Therefore, it is recommended that improving vitamin D status in the general population and in particular hospitalized patients has a potential benefit in reducing the severity of morbidities and mortality associated with acquiring COVID-19.