Drug Repurposing for COVID-19 Therapy: Pipeline, Current Status and Challenges

Repurposed drugs such as Remdesivir, Fabipiravir and Molnupiravir became life saver drugs during the peak of the COVID-19 pandemic, attesting the efficacy of the repurposing approach. By definition, drug repurposing is the process of identification of new therapeutic use of an existing drug or drug candidate that has already passed the safety, toxicity and pharmacology tests for human use. Although drug repurposing approach involves a significant level of challenge, affordability and faster discovery pipeline outweighs the risks in the event of emergency situations like the current COVID-19 pandemic. In this chapter, we provide a brief summary of the advantages of the drug repurposing approach, followed by an overview of the drug repurposing pipeline and finally end with an update on the status of drug repurposing in developing effective anti-viral therapeutics against COVID-19. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.

Effectiveness of ivermectin and atazanavir on time to resolution from COVID-19 symptoms: a prospective cohort

Objective: to evaluate the effectiveness of Ivermectin and Atazanavir compared to placebo in the time to resolution of symptoms and duration of illness due to COVID-19. Method: observational, prospective, longitudinal, descriptive and analytical cohort study with symptomatic outpatients, followed for 06 months in two Basic Health Units for COVID-19 care in Teresina-Piaui, Brazil, from November to April 2021 identified by 1:1:1 random sampling. Reverse transcription polymerase chain reaction (RT-PCR) tests were performed for laboratory confirmation of suspected infection with the new coronavirus and sociodemographic and clinical evaluation. Results: of the 87 randomized patients, 62.1% (n=54) were male, with a mean age of 35.1 years, had a partner (53.9%), low income (50.6%), eutrophic (40.7%) and without health comorbidities (78.2%). There was no difference between the median time to resolution of symptoms, which was 21 days (IQR, 8-30) in the atazanavir group, 30 days (IQR, 5-90) in the ivermectin group compared with 14 days (IQR, 9-21) in the control group. At day 180, there was resolution of symptoms in 100% in the placebo group, 93.9% in the atazanavir group, and 95% in the ivermectin group. The median duration of illness was 8 days in all study arms. Conclusion: Treatment with atazanavir (6 days) and ivermectin (3 days) did not reduce the time to symptom resolution or the duration of illness among outpatients with mild COVID-19 compared to the placebo group. The results do not support the use of ivermectin and atazanavir for the treatment of mild to moderate COVID-19.

Assessing the clinical manifestations, laboratory and radiological findings of hospitalization of pediatrics patients with COVID-19 in pediatric hospital of Amirkola, Babol

Variant Omicron was discovered as a newest severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first emergence of the omicron variant was detected in November 2021. In this study, we investigated the clinical manifestation, laboratory and radiological findings and responding to treatment of 70 pediatric patients with positive RT- PCR COVID-19 in Omicron peak. We described 20 criteria associated with efficacy, such as demographic data, clinical manifestation, laboratory and radiological findings. All of the patients received Remdesivir that 5.7% of patients responded to the treatment. No patients were given Intravenous Immunoglobulin (IVIG). This is the first study aimed at assessing symptoms clinical manifestation among hospitalization pediatrics patients in pediatric Hospital of Amir kola, Babol. The findings of this study can be effective in preventing and controlling disease transmission among children.

Individual intensive nursing care plan for pseudomembranous colitis due to antibiotic treatment of COVID-19

In recent years, a number of complications have been observed as a result of uncontrolled antibiotic treatment. One of them is gastrointestinal dysbiosis. Not infrequently it is the cause of pseudomembranous colitis, a disease with a remarkably high associated mortality. It can be severe and requires serious medical care. This report presents a clinical case of a patient who developed the disease pseudomembranous colitis after antibiotic treatment for a Covid infection. The aim of the report is to define and present in a systematized manner the nursing care provided in the specific case. The daily analysis of the patient's condition allows to offer complex, adequate and individual nursing care, which, in addition to meeting her needs, also aims to alleviate her condition.

The effects of COVID-19 on the water sector

The COVID-19 pandemic affected public health, economy, social life, and the environment. It infected and killed millions of people around the world. Most of the recent literature has focused on the medications to combat this virus, including antivirals and vaccines, but studies about its effect on the environment are still rare, particularly on the water sector. Most of the studies concentrate on the effect of water availability on COVID-19, the effect of the used medications on the water, and the probability of transmission of SARS-CoV-2 through water. Herein, we have summarized the effects of COVID-19 on the water sector from many perspectives. We show different methods to detect the effect of the pandemic on water and also methods to investigate the presence of the virus or its RNA in the water. We also show the different effects of its presence in the wastewater, the probability of transmission, the detection of different variants, and the prediction of new waves. We also show the disadvantages and advantages of the pandemic in the water sector. We finally suggest some recommendations to face this pandemic and the future pandemics for the governments and water policymakers, water treatment plants, general population, and researchers. The aim of this review is to show the different aspects of the pandemic in order to give a general idea about what must be done in order to minimize its effect and any probable pandemic in the future.

Antiviral Chemotherapy and Immunomodulatory Drugs

• Most antiviral drugs available for treatment of feline and canine viral infections are nucleoside analogues with greatest activity against retroviruses, herpesviruses and coronaviruses. • Antiviral drugs also affect the function of host cell machinery;therefore, they have considerable potential for toxicity. • Antiviral drugs are widely used in human medicine for treatment of HIV infection, herpesvirus infection, and other viral. Much less is known about these medications in cats and dogs, and there are only few diseases of cats and dogs for which efficacy has been demonstrated. • There are important differences between human and animal virus infections;therefore, it should not be assumed that the use of an antiviral agent in humans can be translated to a use in animals unless there is evidence of safety and efficacy. • The most common indication for antiviral drugs in animals is treatment of FHV-1 infections with famciclovir and cidofovir. Zidovudine, an antiretroviral drug, has been used to treat FIV and FeLV infections. In addition, new antiviral drugs are now used to treat FIP. • Antiviral drugs can act synergistically with immunomodulatory agents. • Immunomodulators include microbial products, plant-derived immunomodulators, naturally occurring mammalian proteins, and synthetic drugs. The effect of many of these drugs on outcome in cats and dogs with infectious diseases has not been fully evaluated with well-designed studies. • The parenteral use of natural or recombinant human cytokines in cats and dogs can produce neutralizing antibodies after 1 to 2 weeks of treatment, which can cross-react with endogenous proteins. • Antiviral treatments are intended to suppress viral entry, multiplication, or transmission. Some of these antiviral agents can produce a remission or assist the patient's immune system to limit the course of the viral disease. © 2021 Elsevier Inc. All rights reserved.

The effect of hydroxychloroquine in COVID-19 patients who did not receive corticosteroids

Background and Objective: At the beginning of the pandemic, Hydroxychloroquine (HCQ) was one of the most widely used drugs prescribed to patients admitted to hospitals with coronavirus disease 2019 (COVID-19). We try to find the effect of HCQ on the severity and mortality of patients who did not receive corticosteroids. Methods: In this retrospective study, patients with COVID-19 disease were collected from February 20, 2020, to July 21, 2020, at Rouhani Hospital in Babol. Patients were followed up until December 6, 2021. In this study, 170 patients in case and control groups were studied. We used logistic and COX regression models to explore the effects of drugs. Data were analyzed by SPSS version 22. Findings: The use of HCQ did not affect mortality (p=0.46, 95%CI= 0.63 to 2.71, OR= 1.31) and final severity (p= 0.75, 95%CI= 0.59 to 2.06, OR= 1.10) at admission time. However, azithromycin remained in the final model but did not have a significant effect (P= 0.08, HR= 0.28, 95%CI= 0.06 to 0.18). Heparin use was not associated with severity improvement (p= 0.06, 95%CI= 0.97 to 2.81, HR= 1.65), while ceftriaxone remained a factor affecting severity in the model (p = 0.03, 95% CI= 0.29 to 0.95, HR = 0.52). Conclusion: In this study, HCQ harmed mortality admission time and was ineffective in the long term. The use of ceftriaxone compared to other drugs showed protective effects against the mortality hospitalization time. Heparin is not recommended without considering the risk of bleeding in COVID-19 patients.

Retrospective nested study of demographic characteristics, lethality and discharge rate of COVID-19 inpatients in central south of Bulgaria

Introduction: SARS-CoV-2 infection has affected more than 683 million people worldwide with 6.8 million deaths. Unfortunately, Bulgaria is one of the most severely affected European Union (EU) member-states with one of the highest mortality rates. Aim: The study aims to provide a description of the demographic characteristics, discharge rate, and fatality rate of COVID-19-diagnosed patients in one region of Central South Bulgaria in 2021. Materials and methods: A retrospective nested case series study was conducted among patients hospitalized with a confirmed diagnosis of SARS-CoV-2 infection between January 1st and December 31st, 2021. Anonymized patient data on age, sex, admission and discharge dates, treatment, and the outcome was collected from hospital electronic patient records and analyzed using descriptive statistics. Results: Data from 1630 (51% male) patients were identified. The mean age was 63.64 years (+or-15.23). 1342 (82%) of the patients were discharged. The mean age of the diseased was 70.88 years (+or-10.05). 1455 (89%) patients received only symptomatic therapy, 155 (10%) patients were treated with remdesivir (VekluryR), 11 (1%) patients were treated with casirivimab/imdevimab (RonapreveR) and 9 (1%) patients were administered regdanvimab (RegkironaR). Conclusions: The study results demonstrate that Bulgarian patients with COVID-19 were treated according to the best global and national evidencebased guidelines. Lethality and discharge rates are in concordance with global trends and outcomes.

A selectivity-enhanced colloidal crystal array for ribavirin sensing based on the synergistic effect of covalent and non-covalent interactions

Ribavirin is an important antiviral with demonstrated activity against coronaviruses such as severe acute respiratory syndrome coronavirus and coronavirus disease 2019 virus. However, abuse of ribavirin will cause great environmental damage and threaten human health owing to its reproductive toxicity and teratogenicity. Therefore, an innovative detection method is demanded for simple and sensitive detection of ribavirin. This work reports an imprinted colloidal crystal array (ICCA) for ribavirin sensing. The building blocks of the ICCA are ribavirin imprinted spheres, which possess superior binding efficiency toward ribavirin. Benefiting from the highly ordered structure, the ICCA exhibits optical properties which change upon binding ribavirin. The changes in reflectance wavelength enable a fast and label-free detection of ribavirin between 21 and 245 μmol L−1. Moreover, the sensor shows excellent selectivity for ribavirin detection in river water. Overall, all the results reported in this work demonstrate that the ICCA should be a promising detection tool for antivirals. © 2023 Society of Industrial Chemistry. © 2023 Society of Industrial Chemistry.

Drug utilization study in patients affected with COVID-19 in a dedicated COVID hospital

Background: There exists a treatment dilemma regarding the optimal and effective use of therapeutic drugs (hydroxychloroquine/chloroquine/azithromycin) for COVID-19. Furthermore, with changing guidelines, the data on drug utilization patterns across India are limited. Hence, this study was conducted to assess the prescription pattern and drug utilization trends in COVID-19 patients with the aim to study the drug utilization pattern in patients affected with COVID-19 in a dedicated COVID-19 hospital. Aims and Objectives: The objectives of the study are as follows: (1) To study drug utilization patterns according to the severity of the disease. (2) To study the prevalence of adverse drug reactions (ADRs). Materials and Methods: Data were collected retrospectively from 100 medical records of patients 18 years irrespective of sex admitted in the COVID ward and ICU of a dedicated COVID hospital from May to August 2020. Pregnant and lactating women were excluded from the study. ADRs reported were also analyzed. Results: About 71% were mild in this study, 18% were moderate, and 11% were severe COVID-19 patients. Overall, the most common drugs prescribed were multivitamins, followed by pantoprazole, paracetamol, and azithromycin. Hydroxychloroquine was prescribed in 22%, favipiravir in 7%, and remdesivir in 3% of cases. The majority of moderate COVID patients received injectables piperacillin-tazobactam, methylprednisolone, and enoxaparin. The mean number of medications, duration of admission, and number of days on oxygen were higher and significant in moderate compared to mild and severe COVID patients. Overall, ADRs were encountered in 9% of cases. Conclusion: The prescribed pattern of drugs was by the national standard guidelines. Multivitamins, followed by pantoprazole, paracetamol, and azithromycin dominated the prescription pattern. Polypharmacy was encountered, which needs to be addressed for the rational use of drugs.

Structure-based virtual identification of natural inhibitors of SARS-CoV-2 and its Delta and Omicron variant proteins

Plain language summaryMutant strains of SARS-CoV-2 called 'variants of concern' (VOCs) are linked to a good ability to infect, re-infect and spread among people. They are also linked to poor ability to fight the disease and reduced effectiveness of vaccines. Delta and Omicron are important VOCs because they are difficult to control and treat. Specific resistance to some drugs used to treat COVID-19 poses a further challenge. Therefore, discovering natural or plant-derived drugs with no known resistance would be valuable to the treatment of COVID-19. In this study, we screen and identify seven plant-derived compounds that may be useful to treating COVID-19 - we identify Quercetin-3-acetyl-glucoside, Rutin, Kaempferol, Catechin, Orientin, Obetrioside and Neridienone A as potential candidates. Orientin, Obetrioside, Catechin and Neridienone A are identified as candidates against Delta and Omicron for the first time. Aim: Structure-based identification of natural compounds against SARS-CoV-2, Delta and Omicron target proteins. Materials & methods: Several known antiviral natural compounds were subjected to molecular docking and MD simulation against SARS-CoV-2 Mpro, Helicase and Spike, including Delta and Omicron Spikes. Results: Of the docked ligands, 20 selected for each complex exhibited overall good binding affinities (-7.79 to -5.06 kcal/mol) with acceptable physiochemistry following Lipinski's rule. Finally, two best ligands from each complex upon simulation showed structural stability and compactness. Conclusion: Quercetin-3-acetyl-glucoside, Rutin, Kaempferol, Catechin, Orientin, Obetrioside and Neridienone A were identified as potential inhibitors of SARS-CoV-2 Mpro, Helicase and Spike, while Orientin and Obetrioside also showed good binding-affinities with Omicron Spike. Catechin and Neridienone A formed stable complexes with Delta Spike. Tweetable We report structure-based identification of natural compounds viz., Quercetin-3-acetyl-glucoside, Rutin, Kaempferol, Catechin, Orientin, Obetrioside and Neridienone A against SARS-CoV-2 Mpro, Helicase and Spike as well as Delta and Omicron Spike proteins.

Molnupiravir and combination of nirmatrelvir and ritonavir (PaxlovidTM) - oral anti-viral drugs in COVID-19: a systematic review

The COVID-19 pandemic situation demands the discovery of newer drugs and/ or repurposing of the existing drugs. The anti-viral drugs approved for COVID-19 are remdesivir and favipiravir. Two more directly acting oral anti-viral drugs have been granted Emergency Use Authorization by US-FDA, molnupiravir on December 23, 2021, and nirmatrelvir and ritonavir (PaxlovidTM) on December 22, 2021. Molnupiravir, an RNA-dependent RNA polymerase (RdRp) inhibitor, has also been approved in the UK and is under review with other regulatory agencies. PaxlovidTM (a combination of the new anti-viral drugs nirmatrelvir and ritonavir) has been developed and approved by US-FDA and CDSCO, India. Nirmatrelvir acts by inhibiting 3CL (chymotrypsin-like) protease enzyme and it is combined with ritonavir to slow down its breakdown by cytochrome P450 enzymes and to increase the bioavailability. Both molnupiravir and PaxlovidTM have been approved for mild and moderate COVID-19 and in patients who have a higher risk of disease progression to severe disease including hospitalisation and death. This article systematically reviews the clinical trials of molnupiravir and PaxlovidTM that evaluated their efficacy and safety against COVID-19 in both published and unpublished literature.

Special Issue: Honor of Dr. Mike Bray on his retirement as the editor-in-chief of antiviral research. (Special Issue: Honor of Dr. Mike Bray on his retirement as the editor-in-chief of antiviral research.)

This special issue contains 23 articles that discuss various aspects of antiviral research, focusing on the contributions and legacy of Dr. Mike Bray, the retiring Editor-in-Chief of Antiviral Research. The articles cover a range of topics, including the underappreciated mouse model for Ebola virus disease, the history and impact of the mouse-adapted Ebola virus model, and the characterisation of CD-1 mice infected with different strains of Ebola virus. Other articles delve into transplacental vertical transmission of flaviviruses, the development of reverse genetic systems for SARS-CoV-2, and the mechanisms of action and drug resistance of nucleotide analogues against the virus. The special issue also explores therapeutics for flaviviral infections, alternative splicing in RNA virus infections, and targeted protein degradation as an antiviral approach.

19th Seminar on Tropical Pathology and Public Health 12th Biotechnology Week 1st Physical Therapy Week, Virtual, 23-25 November 2022

These proceedings comprise 85 articles spanning diverse fields such as bacteriology, molecular biology, biotechnology, dermatology, infectious and parasitic diseases, epidemiology, physiotherapy, immunology, mycology, parasitology, pathology, collective health, and virology. The articles delve into a wide range of research topics, from repurposing drugs for Mycobacterium abscessus complex infections to utilising artificial intelligence for SARS-CoV-2 diagnosis. In bacteriology, investigations explore the correlation between smoking and Helicobacter pylori infection in gastric adenocarcinoma patients, as well as the resistance profiles of Staphylococcus aureus and Pseudomonas aeruginosa in tracheostomised children. Molecular biology studies focus on gene polymorphisms related to diseases like paracoccidioidomycosis. Biotechnology research emphasises bioactive molecules in species like Croton urucurana and the development of computational models for cytotoxicity prediction. Dermatology articles address stability characterisation in vegetable oil-based nanoemulsions. The section on infectious and parasitic diseases encompasses studies on COVID-19 vaccine response in pregnant women and the impact of infection prevention measures in rehabilitation hospitals. Epidemiology investigations analyse trends in premature mortality, tuberculosis in diabetic patients, and public adherence to non-pharmacological COVID-19 measures. Physiotherapy research covers topics such as telerehabilitation through a developed game and the prevalence of congenital anomalies. Immunology studies explore immune responses in HIV and Leishmaniasis, whilst mycology investigates the biotechnological potential of fungi from the cerrado biome. Parasitology research evaluates treatment efficacy against vectors parasites such as Aedes aegypti and Toxoplasma gondii. Pathology articles discuss intentional intoxication in cattle and the influence of curcumin on acute kidney injury therapy. Collective health studies focus on intervention plan development in healthcare settings and pesticide use in horticulture. Lastly, virology research investigates parvovirus occurrence in hospitalised children during the COVID-19 pandemic, hidden hepatitis B virus infection in inmates, and the prevalence of HPV and HTLV-1/2 infections in specific populations.

In Vitro Antiviral Activity of Nordihydroguaiaretic Acid against SARS-CoV-2.

The coronavirus infectious disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has been spreading rapidly worldwide, creating a pandemic. This article describes the evaluation of the antiviral activity of nordihydroguaiaretic acid (NDGA), a molecule found in Creosote bush (Larrea tridentata) leaves, against SARS-CoV-2 in vitro. A 35 µM concentration of NDGA was not toxic to Vero cells and exhibited a remarkable inhibitory effect on the SARS-CoV-2 cytopathic effect, viral plaque formation, RNA replication, and expression of the SARS-CoV-2 spike glycoprotein. The 50% effective concentration for NDGA was as low as 16.97 µM. Our results show that NDGA could be a promising therapeutic candidate against SARS-CoV-2.

Broad-Spectrum Antivirals Derived from Natural Products.

Scientific advances have led to the development and production of numerous vaccines and antiviral drugs, but viruses, including re-emerging and emerging viruses, such as SARS-CoV-2, remain a major threat to human health. Many antiviral agents are rarely used in clinical treatment, however, because of their inefficacy and resistance. The toxicity of natural products may be lower, and some natural products have multiple targets, which means less resistance. Therefore, natural products may be an effective means to solve virus infection in the future. New techniques and ideas are currently being developed for the design and screening of antiviral drugs thanks to recent revelations about virus replication mechanisms and the advancement of molecular docking technology. This review will summarize recently discovered antiviral drugs, mechanisms of action, and screening and design strategies for novel antiviral agents.

Structure-guided pharmacophore based virtual screening, docking, and molecular dynamics to discover repurposed drugs as novel inhibitors against endoribonuclease Nsp15 of SARS-CoV-2.

COVID-19 (Corona Virus Disease of 2019) caused by the novel 'Severe Acute Respiratory Syndrome Coronavirus-2' (SARS-CoV-2) has wreaked havoc on human health and the global economy. As a result, for new medication development, it's critical to investigate possible therapeutic targets against the novel virus. 'Non-structural protein 15' (Nsp15) endonuclease is one of the crucial targets which helps in the replication of virus and virulence in the host immune system. Here, in the current study, we developed the structure-based pharmacophore model based on Nsp15-UMP interactions and virtually screened several databases against the selected model. To validate the screening process, we docked the top hits obtained after secondary filtering (Lipinski's rule of five, ADMET & Topkat) followed by 100 ns molecular dynamics (MD) simulations. Next, to revalidate the MD simulation studies, we have calculated the binding free energy of each complex using the MM-PBSA procedure. The discovered repurposed drugs can aid the rational design of novel inhibitors for Nsp15 of the SARS-CoV-2 enzyme and may be considered for immediate drug development.

Promising antivirals for PLpro of SARS-CoV-2 using virtual screening, molecular docking, dynamics, and MMPBSA.

The recent pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (COVID-19) is a viral respiratory disease that has been spread all over the globe. Therefore, it is an urgent requirement to identify and develop drugs for this contagious infection. The papain-like protease (PLpro) of SARS-CoV-2 performs critical functions in virus replication and immune evasion, making it an enticing therapeutic target. SARS-CoV-2 and SARS-CoV PLpro proteases have significant similarities, and an inhibitor discovered for SARS-CoV PLpro is an exciting first step toward therapeutic development. Here, a set of antiviral molecules were screened at the catalytic and S-binding allosteric sites of papain-like protease (PLpro). Molecular docking results suggested that five molecules (44560613, 136277567, S5652, SC75741, and S3833) had good binding affinities at both sites of PLpro. Molecular dynamics analysis like root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration (Rg), solvent accessible surface area (SASA), and hydrogen bond results showed that identified molecules with PLpro tend to form stable PLpro-inhibitor(s) complexes. Molecular Mechanics/Position-Boltzmann Surface Area (MMPBSA) analysis confirmed that antiviral molecules bound PLpro complex had lower energy (-184.72 ± 7.81 to -215.67 ± 6.73 kJ/mol) complexes. Noticeably, computational approaches revealed promising antivirals candidates for PLpro, which may be further tested by biochemical and cell-based assays to assess their potential for SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

Estimation of Intangible Costs for Factors Associated with Oral Antiviral Drugs for COVID-19 Treatment: A Conjoint Analysis in Japan.

INTRODUCTION: During the recent coronavirus disease 2019 (COVID-19) pandemic, preferences for factors associated with vaccines have been evaluated. Three oral antiviral drugs have been approved in Japan for patients with mild-to-moderate I COVID-19 symptoms. Although preferences for the drugs may also depend on various factors, these have not been fully evaluated. METHODS: A conjoint analysis was performed based on an online survey in August 2022 to estimate the intangible costs of factors associated with oral antiviral drugs for COVID-19. Respondents were individuals aged 20-69 across Japan. The attributes included the company (Japanese/foreign) that developed the drug, formulation and size of the drug, frequency of administration per day, number of tablets/capsules per dose, number of days until no longer infectious to others, and out-of-pocket expenses. A logistic regression model was applied to estimate the utility of each level for each attribute. The intangible costs were calculated by comparing the utility to the out-of-pocket attribute. RESULTS: Responses were collected from 11,303 participants. The difference between levels was the largest for companies that developed a drug; the intangible costs were JPY 5390 higher for the foreign company than for the Japanese company. The next largest difference was in the number of days until one is no longer infectious. For the same formulation, the intangible cost was lower for small sizes than large sizes. For similar-sized tablets and capsules, the intangible cost was lower for tablets than capsules. These tendencies were similar regardless of COVID-19 infection history and the presence of risk factors for severe COVID-19 in the respondents. CONCLUSION: Intangible costs for factors associated with oral antiviral drugs among the Japanese population were estimated. The results may change as the number of people with a history of COVID-19 infection increases and significant progress is made regarding treatments.

Molnupiravir, Nirmatrelvir/Ritonavir, or Sotrovimab for High-Risk COVID-19 Patients Infected by the Omicron Variant: Hospitalization, Mortality, and Time until Negative Swab Test in Real Life.

Background. Several drugs which are easy to administer in outpatient settings have been authorized and endorsed for high-risk COVID-19 patients with mild-moderate disease to prevent hospital admission and death, complementing COVID-19 vaccines. However, the evidence on the efficacy of COVID-19 antivirals during the Omicron wave is scanty or conflicting. Methods. This retrospective controlled study investigated the efficacy of Molnupiravir or Nirmatrelvir/Ritonavir (Paxlovid®) or Sotrovimab against standard of care (controls) on three different endpoints among 386 high-risk COVID-19 outpatients: hospital admission at 30 days; death at 30 days; and time between COVID-19 diagnosis and first negative swab test result. Multivariable logistic regression was employed to investigate the determinants of hospitalization due to COVID-19-associated pneumonia, whereas time to first negative swab test result was investigated by means of multinomial logistic analysis as well as Cox regression analysis. Results. Only 11 patients (overall rate of 2.8%) developed severe COVID-19-associated pneumonia requiring admission to hospital: 8 controls (7.2%); 2 patients on Nirmatrelvir/Ritonavir (2.0%); and 1 on Sotrovimab (1.8%). No patient on Molnupiravir was institutionalized. Compared to controls, hospitalization was less likely for patients on Nirmatrelvir/Ritonavir (aOR = 0.16; 95% CI: 0.03; 0.89) or Molnupiravir (omitted estimate); drug efficacy was 84% for Nirmatrelvir/Ritonavir against 100% for Molnupiravir. Only two patients died of COVID-19 (rate of 0.5%), both were controls, one (a woman aged 96 years) was unvaccinated and the other (a woman aged 72 years) had adequate vaccination status. At Cox regression analysis, the negativization rate was significantly higher in patients treated with both antivirals-Nirmatrelvir/Ritonavir (aHR = 1.68; 95% CI: 1.25; 2.26) or Molnupiravir (aHR = 1.45; 95% CI: 1.08; 1.94). However, COVID-19 vaccination with three (aHR = 2.03; 95% CI: 1.51; 2.73) or four (aHR = 2.48; 95% CI: 1.32; 4.68) doses had a slightly stronger effect size on viral clearance. In contrast, the negativization rate reduced significantly in patients who were immune-depressed (aHR = 0.70; 95% CI: 0.52; 0.93) or those with a Charlson index ≥5 (aHR = 0.63; 0.41; 0.95) or those who had started the respective treatment course 3+ days after COVID-19 diagnosis (aOR = 0.56; 95% CI: 0.38; 0.82). Likewise, at internal analysis (excluding patients on standard of care), patients on Molnupiravir (aHR = 1.74; 95% CI: 1.21; 2.50) or Nirmatrelvir/Ritonavir (aHR = 1.96; 95% CI: 1.32; 2.93) were more likely to turn negative earlier than those on Sotrovimab (reference category). Nonetheless, three (aHR = 1.91; 95% CI: 1.33; 2.74) or four (aHR = 2.20; 95% CI: 1.06; 4.59) doses of COVID-19 vaccine were again associated with a faster negativization rate. Again, the negativization rate was significantly lower if treatment started 3+ days after COVID-19 diagnosis (aHR = 0.54; 95% CI: 0.32; 0.92). Conclusions. Molnupiravir, Nirmatrelvir/Ritonavir, and Sotrovimab were all effective in preventing hospital admission and/or mortality attributable to COVID-19. However, hospitalizations also decreased with higher number of doses of COVID-19 vaccines. Although they are effective against severe disease and mortality, the prescription of COVID-19 antivirals should be carefully scrutinized by double opinion, not only to contain health care costs but also to reduce the risk of generating resistant SARS-CoV-2 strains. Only 64.7% of patients were in fact immunized with 3+ doses of COVID-19 vaccines in the present study. High-risk patients should prioritize COVID-19 vaccination, which is a more cost-effective approach than antivirals against severe SARS-CoV-2 pneumonia. Likewise, although both antivirals, especially Nirmatrelvir/Ritonavir, were more likely than standard of care and Sotrovimab to reduce viral shedding time (VST) in high-risk SARS-CoV-2 patients, vaccination had an independent and stronger effect on viral clearance. However, the effect of antivirals or COVID-19 vaccination on VST should be considered a secondary benefit. Indeed, recommending Nirmatrelvir/Ritonavir in order to control VST in high-risk COVID-19 patients is rather questionable since other cheap, large spectrum and harmless nasal disinfectants such as hypertonic saline solutions are available on the market with proven efficacy in containing VST.