WO2021224646A1 - Method for the treatment of rna virus involved diseases - Google Patents

Abstract

The present invention relates to a nucleoside analogue for use in the treatment of an RNA virus involved infections and associated diseases in a human, wherein the nucleoside analogue is selected from the group consisting of methylation inhibitors, 1'-cyano substituted nucleosides, flaviviral methyltransferase and rigid amphipathic nucleosides, ribavirin and other nucleoside synthesis inhibitors and rigid amphipathic nucleosides.

Description

METHOD FOR THE TREATMENT OF RNA VIRUS INVOLVED DISEASES

BACKGROUND OF THE INVENTION

[1] The continuous growth of the human population closely linked to globalization, trade, and habitat fragmentation increasingly promote contact between people, domestic animals, and wildlife populations. Such contact between formerly isolated populations increases the risk of transmission of viruses to which they had not been exposed before. Virus-associated epidemics have significantly altered and reshaped human history. Numbers of the most devastating human diseases caused by RNA viruses including the common cold (Rhinoviruses), influenza (Influenza A, B and C virus), severe acute respiratory syndrome or SARS (SARS-CoV-1 virus), coronavirus disease 2019 or COVID-19 (SARS-CoV-2 virus), hepatitis C (HCV), hepatitis E (HEV), West Nile fever (WNV), Ebola (EBOV, BDBV, TAFV and SUDV), rabies (Lyssaviruses), poliomyelitis (Poliovirus) and measles (MeV). The increasing human interaction with wild environments has induced number of pandemics originated from wildlife reservoirs, as was seen with the emergence of the Human Immunodeficiency Virus (HIV), H1N1 influenza, the highly pathogenic H5N1 avian influenza Nipah, Hendra, the Severe Acute Respiratory Syndrome Coronavirus (SARS, MERS, COVID-19), and the recent Ebola virus (EBOV).

[2] RNA viruses have become important zoonotic agents originating from wildlife. Studies from the last decades have placed RNA viruses as primary etiological agents of human emerging pathogens, occupying up to 44% of all emerging infectious diseases (Binder et al. 1999; Jones et al. 2008; Morens et al. 2004; Woolhouse and Gowtage-Sequeria 2005). RNA viruses have higher probabilities to infect new host species because of their exceptionally shorter generation times and their faster evolutionary rates. The rapid evolutionary rates of RNA viruses build from frequent error-prone replication cycles (Holmes 2009). Mutation rates of RNA viruses can occur - roughly - at rates of six orders of magnitude greater than those of their cellular hosts (Holmes 2009). Moreover, their mutability can even surpass that of some DNA viruses by up to five orders of magnitude (e.g., 1.5 ^c 10 ³ mutations per nucleotide, per genomic replication [m/n/gr] in the single-stranded RNA phage QP10, versus 1.8 x 10 ⁸ m/n/gr in the double-stranded DNA virus herpes simplex virus type 1 (Duffy et al. 2008). [3] By definition RNA virus is a virus that has RNA (ribonucleic acid) as its genetic material. RNA viral genomes can be double-stranded RNA genomes (dsRNA) (Reoviridae) or single-stranded RNA genomes (ssRNA) (most RNA viruses) or positive-sense RNA viruses (+ssRNA) (e.g., Retroviridae, Togaviridae, Flaviviridae, Coronaviridae, Hepeviridae, Caliciviridae, Picornaviridae) or negative-sense RNA viruses (-ssRNA) (e.g., Arenaviridae, Bunyaviridae, Paramyxoviridae, Orthomyxoviridae, Filoviridae, Rhabdoviridae). However, there are significant differences regarding their life cycles it is a common point that ribonucleotides are building units of every RNA virus genomes (Figure 1).

[4] A virus can only survive within a host cell and depends on it for replication and metabolic processes, e.g., protein synthesis. Virion is the infective form of a virus when present outside of cells, which consists of DNA or RNA, a protein capsid, and sometimes an envelope.

[5] Viruses replicate by synthesizing and assembling their individual components within the host cell. Steps are (1) attachment to the host cell in which the viruses use host cell surface proteins and receptors for entry (see receptors used by viruses below), (2) penetration into the host cell: nonenveloped viruses via endocytosis or transmembrane transport or enveloped viruses via endocytosis or fusion with host cell's cell membrane, (3) uncoating of the nucleic acid, (4) replication of the nucleic acid and formation of virus proteins by transcription and translation (in retroviruses, RNA is initially transcribed into DNA): (a) early mRNA is for the synthesis of proteins to shut down host cell defense mechanisms or proteins for genome replication (e.g., viral RNA polymerase) and (b) late mRNA is for the synthesis of viral structural proteins, (5) assembly of virus components, (6) viral release: (a) enveloped viruses: released via budding or (b) nonenveloped viruses: released via host cell lysis (Figure 1).

[6] Viruses use host cell surface proteins and receptors to attach and penetrate the cells. Receptors used by viruses are CMV: integrins (e.g., heparan sulfate), EBV: CD21, HIV: CD4,

CXCR4, CCR5, Parvovirus B19: P antigen on erythrocytes, Rhabdovirus: nicotinic acetylcholine receptor, Rhinovirus: ICAM-1.

[7] Mechanisms by which viruses cause infection in the host are (1) cytolysis: viral replication results in the destruction of host cell release of virus (nonenveloped viruses and some enveloped viruses) or (2) immunopathological host reactions: cellular immune response to the invading virus is triggered by cytotoxic T cells destruction of infected cells (e.g., HBV); the virus, however, is not cytopathogenic or (3) transfer of genetic material: bacteriophages may transfer virulence factors (e.g., exotoxins). [8] Course of viral infection can be abortive (no viral replication or cell damage), acute, chronic, persistent, latent (inactive; no replication): virus remains dormant in infected cells, productive (viral replication occurs, dormant infection with few or no signs of infection) and transforming (virus may or may not replicate): triggers malignant transformation (e.g., EBV, HPV).

[9] The human body has multiple defense mechanisms to inactivate and eliminate viruses: (1) innate immune response can be (a) physical, biological, and chemical defenses such as keratinocytes are impermeable to viruses or mucociliary clearance of respiratory tract (transports viruses towards the throat) or production of acid and viral replication inhibitors by commensal organisms; (b) RNA interference (only against RNA viruses), (c) natural killer cells, (d) complement system, (e) interferon: IFN-alpha and IFN-beta: produced by infected cells or triggers damage and death of infected cells or inhibit viral replication and viral protein synthesis (RNA endonucleases: cleave phosphodiester bonds between nucleotides or phosphorylation of protein kinases inactivation of eIF2 inhibition of protein synthesis); (2) Adaptive immune response: (a) immunoglobulins or (b) T cells.

[10] Medical efforts to control viral diseases comprise a variety of strategies at different levels, ranging from the design of drug substances to field surveillance. However, control of RNA viral diseases has been difficult because their high adaptive rates enable them to rapidly acquire genetic resistance against traditional control measures (e.g., vaccination or single drug therapies). Thus, modern technologies must also “diversify and evolve” at fast rates to control these rapidly evolving pathogenic agents. Additionally, surveillance and control of a diversity of host populations and reservoirs in the field also plays a key role in overall control measures.

[11] Coronavirus disease 2019 (COVID-19) is defined as illness caused by a novel coronavirus now called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; formerly called 2019-nCoV), which was first identified amid an outbreak of respiratory illness cases in Wuhan City, Hubei Province, China.

[12] There are no specific clinical features that can yet reliably distinguish COVID-19 from other viral respiratory infections. The incubation period for COVID-19 is thought to be within 14 days following exposure, with most cases occurring approximately four to five days after exposure. Dyspnea (shortness of breath) can be suggestive several days after the onset of initial symptoms. Pneumonia appears to be the most frequent serious manifestation of infection, characterized primarily by fever, cough, dyspnea, and bilateral infiltrates on chest imaging. However, other features, including upper respiratory tract symptoms, myalgias (muscle aches), diarrhea, and smell or taste disorders, are also common. Severe illness can occur in otherwise healthy individuals of any age, but it predominantly occurs in adults with advanced age or underlying medical comorbidities. Comorbidities that have been associated with severe illness are cardiovascular disease, hypertension, chronic lung and kidney diseases, cancer and obesity.

[13] Although the primary COVID-19 pathogenesis was thought as pulmonary type II pneumocyte injury, viral pneumonia, acute respiratory distress syndrome (ARDS) or macrophage activating like syndrome complicating ARDS leading to disseminated intravascular coagulation (DIC). COVID-19 may predispose to both venous and arterial thromboembolic disease due to excessive inflammation, hypoxia, immobilization and DIC. Symptomatic acute pulmonary embolism (PE), deep-vein thrombosis (DVT), ischemic stroke, myocardial infarction or systemic arterial embolism were reported as comorbidities in COVID19 infected patients {Kloket al. 2020).

[14] SARS-CoV-2, the coronavirus that causes COVID-19, may cause neurological disorders by directly infecting the brain or as a result of the strong activation of the immune system. Cells in the human brain express the ACE2 protein on their surface. ACE2 is a protein involved in blood pressure regulation and is the receptor the virus uses to enter and infect cells. ACE2 is also found on endothelial cells that line blood vessels. Infection of endothelial cells may allow the virus to pass from the respiratory tract to the blood and then across the blood-brain barrier into the brain. Once in the brain, replication of the virus may cause neurological disorders. SARS-CoV-2 infection also results in a very strong response by the immune system.

[15] COVID-19 results in neurological damage likely by two mechanisms; hypoxic brain injury and an immune mediated damage to the CNS. Hypoxic brain injury, where severe pneumonia can result in systemic hypoxia leading to brain damage. The contributory factors include peripheral vasodilatation, hypercarbia, hypoxia, and anaerobic metabolism with accumulation of toxic compounds. These can result in neuronal swelling and brain edema which ultimately results in neurological damage. 2. Immune mediated injury is mainly due to the cytokine storms with increased levels of inflammatory cytokines and activation of T lymphocytes, macrophages, and endothelial cells. Further release of Interleukins 6 causes vascular leakage, activation of complement and coagulation cascade, disseminated intravascular coagulation and end organ damage.

[16] The neurological manifestations and complications of COVID-19 can be divided into central such as dizziness, headache, acute cerebrovascular disease, impaired consciousness, transverse myelitis, acute hemorrhagic necrotizing encephalopathy, encephalopathy encephalitis, epilepsy, ataxia and peripheral such as hypogeusia, hyposmia, neuralgia, Guillain Barre syndrome, skeletal muscle injury (Ahmad et al. 2020).

[17] Other cases studies have described severe COVID-19 encephalitis (brain inflammation and swelling) and stroke in healthy young people with otherwise mild COVID-19 symptoms

(Rossman, 2020).

[18] Unusual numbers of children and teenagers tested positive for COVID-19 have developed an inflammatory condition (officially called Multisystem Inflammatory Syndrome in Children, or MIS-C) that looks a lot like Kawasaki disease. It is deadlier than Kawasaki disease, but both conditions share number of symptoms with MIS-C, including fever, red eyes, skin rash and body pains. Some doctors believe it may be some kind of delayed reaction of the child's immune system that is abnormal and unusually aggressive. Doctors speculate that while trying to fight off the virus, children's immune systems overreact and start damaging normal, healthy cells, like those in their organs. They suggest this also could be what leads to the dangerous drop in blood pressure often observed. Since then, doctors have reported clusters of pediatric COVID-19 cases that presented with Kawasaki disease (PDF) and related symptoms, such as persistent fever, reddened eyes, skin rash and joint and abdominal pain (Smith, 2020).

[19] Emerging reports suggest that as many as one third of patients with severe COVID-19 infection requiring intensive care may also be battling another life-threatening infection: invasive aspergillosis, a deadly fungal superinfection caused by Aspergillus mold. This infection is caused by microscopic Aspergillus spores, which are typically present in the air we breathe. Poorly controlled aspergillosis can disseminate through the blood stream to cause widespread organ damage. The person may develop kidney failure, liver failure and further increasing breathing difficulties (Ben-Ami, 2021). People who, for example, are severely immunocompromised as a result of cancer treatment or immunosuppressive medications can become seriously ill after breathing in this dangerous fungal pathogen, with mortality rates ranging from 40 to 90 percent even after treatment with existing antifungal therapies. Acinetobacter baumannii , Klebsiella pneumoniae , and Aspergillus flavus , Candida glabrata, Candida albicans , Enterobacter cloacae , Acinetobacter baumannii and Legionella pneumophillia have been also identified in patients with COVID-19 infection (Rawson et al. 2020).

[20] SARS-CoV2 infection can be divided into 3 consecutive stages. Stage 1 is the initial 1-2 days with no sign of infection (i.e., asymptomatic state). The inhaled virus SARS-CoV-2 binds to epithelial cells in the nasal cavity and starts replicating. ACE2 is the main receptor for SARS-CoV2 and after internalization there is local propagation of the virus with a limited innate immune response. At this stage the virus can be already detected by nasal swabs using RT-PCR. In Stage 2, the virus propagates and migrates down the respiratory tract along the conducting airways, and infects epithelial cells triggering a more robust innate immune response. Virus infected epithelial cells are expressing beta and lambda interferons, however, about 20% of the infected patients will progress to stage 3 disease and will develop pulmonary infiltrates and some of these will develop severe disease acute respiratory distress syndrome (ARDS). The virus now reaches the gas exchange units of the lung and infects alveolar type II cells wherein it can replicate, and large number of viral particles are released. This high virus load and appearance of virus-specific antibodies can trigger more immune- pathological processes such as antibody-dependent enhancement and faulty Th2 reaction leading to virus infection of immune cells and expression of high level of inflammatory cytokines (cytokine storm), which is characteristic for ARDS. Infected cells undergo apoptosis and result is serious alveolar damage with fibrin rich hyaline membranes and a few multinucleated giant cells. High cytokine level also triggers severe inflammation that affects blood vessels, triggering clots formation that might lead to stroke. The lung will likely lose most of their type II cells, and epithelial regeneration will be triggered. The aberrant wound healing may lead to more severe scaring and fibrosis than other forms of ARDS.

[21] The microbial diagnosis of COVID-19 is made by detection of SARS-CoV-2 RNA by reverse transcription polymerase chain reaction (RT-PCR). Various RT-PCR assays are used around the world; different assays amplify and detect different regions of the SARS-CoV-2 genome. Common gene targets include nucleocapsid (N), envelope (E), spike (S), and RNA- dependent RNA polymerase (RdRp), as well as regions in the first open reading frame.

[22] Theoretically, each step of virus life cycle can be a potential target for anti-virus therapy. However, the two most frequent targets are (1) virus adsorption/penetration, which is linked to the activation of adaptive immune system or (2) intracellular events leading to effective virus maturation. Such events include inhibition of virus genome replication or transcription, viral mRNA translation, virus enzyme catalysis or virus maturation. Nucleotides are building blocks of viral RNA and their analogs can interfere with virus replication, transcription and translation. Many of the compounds have been investigated stem from anti cancer treatment studies and proved to be clinically useful as antiviral and anticancer drugs.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows RNA virus life cycles. Each type of virus replication goes thought some RNA intermediates.

Figure 2 shows virus infection-induced adaptive immune responses. A) Successful cellular immune response. Host cell with appropriate virus receptors is infected. Cytotoxic T lymphocytes (TLCs) eliminate virus infected host cells. Virus-specific antibody (IgG) expression grows in host leading to elimination of viruses and virus-infected cells by members of adaptive and innate immune systems. B) Unsuccessful cellular immune response. Virus-specific IgGs cover viruses and immune cells with Fc receptors (FcRs) adsorb and internalize viruses leading to elevated inflammatory cytokine expression (i.e., cytokine storm). Cytokine storm-induces hyperactive immune reaction and immune cells spread beyond infected body parts and start attacking healthy tissues (ADE). Blood vessels may get so leaky that the lungs fill with fluid, blood clots are formed, and blood flow is compromised leading a person go into shock, risking organ damage or death. C) Dual-acting agent (5- azacitidine and its derivative) blocking virus replication and IgG production. After blocking agent treatment, RNA-dependent polymerases incorporate modified ribonucleotides into viral RNA leading to blocked virus replication and production. At the same time, dual-acting agent interferes with B cell development leading to reduced antibody production, which acts against cytokine storm and other permanent adverse effects.

BRIEF DESCRIPTION OF THE INVENTION [23] 1. A nucleoside analogue for use in treating an RNA virus involved infections and associated diseases in a human, wherein the use comprises administering therapeutically effective amount of the nucleoside analogue, wherein the nucleoside analogue is selected from the group of methylation inhibitors, V- cyano substituted nucleosides, flaviviral methyltransferase and rigid amphipathic nucleosides, ribavirin and other nucleoside synthesis inhibitors and rigid amphipathic nucleosides, wherein the methylation inhibitors are 5-azacitidine, 5-aza-2'-deoxycytidine, 5-fluoro-2'- deoxycytidine, and zebularine; and wherein l’-cyano substituted nucleosides are selected from l’-cyano substituted C-nucleoside derived from 4-aza-7,9-dideazaadenosine, 2’-C-methyladenosine, 7-deaza-2’-C-methyl- adenosine, phosphoramidate prodrug of 6-0-methyl-2’-C-methylguanosine, 2’-C- methylcytidine, 2’-C-methyluridine, 2’ -C-ethynyl adenosine, Sofosbuvir, 7-deaza derivative of 2’-C-ethynyladenosine, 2’-ethynyl modified derivative of 7-deaza derivative of 2’-C- ethynyladenosine, isobutyryl ester prodrug of 2’-ethynyl modified derivative of 7-deaza derivative of 2’-C-ethynyladenosine, 4’-C-azidocytidine, Balapiravir, RO-9187, BCX4430, T- 1106, 6-Methyl-7-deazaadenosine, N6-(9-antranylmethyl) adenosine, N6-(l-pyrenylmethyl) adenosine, N6-benzyl-5’-0-triisopropylsilyl adenosine, N6-benzyl-5’-0-trityl adenosine, N6- benzyl-5 ’ -O-tert-butyldimethylsilyl-adenosine, T , 5 ’ -di-O-trityluridine, 3 ’ ,5 ’ -di-O- trityluridine; and wherein the ribavirin and other nucleoside synthesis inhibitors are selected from ribavirin, 1- beta-D-ribofuranosyl-3-ethynyl-[l,2,4]triazole and 6-azauridine; and wherein the rigid amphipathic nucleosides are selected from 5-(perylen-3-yl)ethynyl-arabino- uridine, 5-(perylen-3-yl)ethynyl-2’-deoxy-uridine and 5-(pyren-l-yl)ethynyl-20-deoxy- uridine.

[24] 2. The nucleoside analogue for use of point 1, wherein the nucleoside analogue is 5- azacitidine.

[25] 3. The nucleoside analogue for use of point 1, wherein said therapeutically effective amount of a nucleoside analogue is 5-75 mg/m2 or 0.1-2.5 mg/kg dose.

[26] 4. The nucleoside analogue for use of point 1, wherein said RNA virus is a positive- sense RNA virus (+ssRNA) and selected from the group of coronaviridae, flaviviridae and togaviridae, wherein the coronaviridae are selected from the group of 29E (alpha coronavirus), NL63 (alpha coronavirus), OC43 (beta coronavirus), HKU1 (beta coronavirus), MERS-CoV (the beta coronavirus that causes Middle East Respiratory Syndrome, or MERS), SARS-CoV (the beta coronavirus that causes Severe Acute Respiratory Syndrome, or SARS) and SARS-CoV- 2 (the novel coronavirus that causes coronavirus disease 2019, or COVID-19).

[27] 5. The nucleoside analogue for use of point 4, wherein the coronaviridae are selected from MERS-CoV (the beta coronavirus or MERS), SARS-CoV (the beta coronavirus or SARS) and SARS-CoV-2 (COVID-19).

[28] 6. The nucleoside analogue for use of point 1, wherein the RNA virus involved diseases are Middle East Respiratory Syndromes and Severe Acute Respiratory Syndromes.

[29] 7. The nucleoside analogue for use of point 1, wherein the therapeutically effective amount of the nucleoside analogue is administered as add-on therapy to standard of care.

[30] 8. The nucleoside analogue for use of point 1, wherein the therapeutically effective amount of the nucleoside analogue is administered subcutaneously or intravenously at 5-75 mg/m² or 0.1-2.5 mg/kg dose for 3-14 days. [31] 9. The nucleoside analogue for use of point 1, wherein the RNA virus involved and associated diseases are selected from the group of upper respiratory tract viral infection showing nonspecific symptoms such as fever, fatigue, cough, anorexia, malaise, muscle pain, sore throat, dyspnea, nasal congestion, or headache; and/or have pneumonia with no signs of severe pneumonia and no need for supplemental oxygen; and/or have severe pneumonia; and/or infection related complications, such as acute respiratory distress syndrome (ARDS), acute respiratory failure, cardiovascular complications including venous and arterial thromboembolic diseases such as symptomatic acute pulmonary embolism, deep-vein thrombosis, stroke, ischemic stroke, myocardial infarction or systemic arterial embolism, acute liver injury, cytokine release syndrome including multisystem inflammatory syndrome and Kawasaki disease, septic shock, disseminated intravascular coagulation, venous thromboembolism, secondary infection, acute kidney injury, pancreatic injury, neurologic complications including hypoxic brain injury, where severe pneumonia can result in systemic hypoxia leading to brain damage and immune mediated injury that causes vascular leakage, activation of complement and coagulation cascade, dizziness, headache, acute cerebrovascular disease, impaired consciousness, transverse myelitis, acute hemorrhagic necrotizing encephalopathy, ancephalopathy ancephalitis, apilepsy, ataxia and peripheral such as hypogeusia, hyposmia, neuralgia, Guillian Barre syndrome, skeletal muscle injury, disseminated intravascular coagulation and end organ damage, rhabdomyolysis, pregnancy- related complications and secondary infections including aspergillosis, Acinetobacter baumannii , Klebsiella pneumoniae , Aspergillus flavus , Candida glabrata, Candida albicans , Enterobacter cloacae , Acinetobacter baumannii and Legionella pneumophillia.

[32] 10. A nucleoside analogue for use in the treatment of post-acute syndromes of RNA viruses involved infections and associated diseases in a human, wherein the use comprisesadministering therapeutically effective amount of the nucleoside analogue.

[33] 11. The nucleoside analogue for use of point 10, wherein the post-acute syndromes of RNA viruses involved infections includes highest risk for long-term pulmonary complications, including persistent diffusion impairment and radiographic pulmonary abnormalities (such as pulmonary fibrosis), thromboprophylaxis including segmental pulmonary embolism, intracardiac thrombus, thrombosed arteriovenous fistula and ischemic stroke, postural orthostatic tachycardia syndrome and inappropriate sinus tachycardia, chronic malaise, diffuse myalgia, depressive symptoms and non-restorative sleep, ischemic or hemorrhagic stroke, hypoxic-anoxic damage, posterior reversible encephalopathy syndrome and acute disseminated myelitis, myopathy and neuropathies, renal sequelae, subacute thyroiditis with clinical thyrotoxicosis, latent thyroid autoimmunity, new-onset Hashimoto’s thyroiditis or Graves’ disease, significant gastrointestinal and hepatobiliary sequelae, neurological complications, such as headache, altered mental status, encephalopathy, cranial nerve palsies, stroke, seizure, reduced reflexes, muscle weakness and Guillain Barre Syndrome.

[34] 12. The nucleoside analogue for use of point 10, wherein the nucleoside analogue is 5- azacitidine.

[35] 13. A nucleoside analogue for use in treating the symptoms of short- and long-term adverse events and related diseases following immunization by vaccine to prevent RNA viruses involved infections and associated diseases in a human, wherein the use comprises administering therapeutically effective amount of the nucleoside analogue.

[36] 14. The nucleoside analogue for use of point 13, wherein the nucleoside analogue is 5- azacitidine.

[37] 15. A method of treating an RNA virus involved infections and associated diseases in a human by administering therapeutically effective amount of a nucleoside analogue, wherein the nucleoside analogue is selected from the group of methylation inhibitors, G-cyano substituted nucleosides, flaviviral methyltransferase and rigid amphipathic nucleosides, ribavirin and other nucleoside synthesis inhibitors and rigid amphipathic nucleosides, wherein the methylation inhibitors are 5-azacitidine, 5-aza-2'-deoxycytidine, 5-fluoro-2'- deoxycytidine, and zebularine; and wherein G-cyano substituted nucleosides are selected from G-cyano substituted C-nucleoside derived from 4-aza-7,9-dideazaadenosine, 2’-C-methyladenosine, 7-deaza-2’-C-methyl- adenosine, phosphoramidate prodrug of 6-0-methyl-2’-C-methylguanosine, 2’-C- methylcytidine, 2’-C-methyluridine, 2 ’-C-ethynyl adenosine, Sofosbuvir, 7-deaza derivative of 2’-C-ethynyladenosine, 2’-ethynyl modified derivative of 7-deaza derivative of 2’-C- ethynyladenosine, isobutyryl ester prodrug of 2’-ethynyl modified derivative of 7-deaza derivative of 2’-C-ethynyladenosine, 4’-C-azidocytidine, Balapiravir, RO-9187, BCX4430, T-1106, 6-Methyl-7-deazaadenosine, N6-(9-antranylmethyl) adenosine, N6-(l- pyrenylmethyl) adenosine, N6-benzyl-5’-0-triisopropylsilyl adenosine, N6-benzyl-5’-0-trityl adenosine, N6-benzyl-5’-0-tert-butyldimethylsilyl-adenosine, 2’,5’-di-0-trityluridine, 3’,5’- di-O-trityluridine; and wherein the ribavirin and other nucleoside synthesis inhibitors are selected from ribavirin, 1- beta-D-ribofuranosyl-3-ethynyl-[l,2,4]triazole and 6-azauridine; and wherein the rigid amphipathic nucleosides are selected from 5-(perylen-3-yl)ethynyl-arabino- uridine, 5-(perylen-3-yl)ethynyl-2’-deoxy-uridine and 5-(pyren-l-yl)ethynyl-20-deoxy- uridine.

[38] 16. The method of point 15, wherein the nucleoside analogue is 5-azacitidine.

[39] 17. The method of point 15, wherein said therapeutically effective amount of a nucleoside analogue is 5-75 mg/m² or 0.1-2.5 mg/kg dose.

[40] 18. The method of point 15, wherein said RNA virus is a positive-sense RNA virus (+ssRNA) and selected from the group of coronaviridae, flaviviridae and togaviridae, wherein the coronaviridae are selected from the group of 29E (alpha coronavirus), NL63 (alpha coronavirus), OC43 (beta coronavirus), HKU1 (beta coronavirus), MERS-CoV (the beta coronavirus that causes Middle East Respiratory Syndrome, or MERS), SARS-CoV (the beta coronavirus that causes Severe Acute Respiratory Syndrome, or SARS) and SARS-CoV- 2 (the novel coronavirus that causes coronavirus disease 2019, or COVID-19).

[41] 19. The method of point 18, wherein the coronaviridae are selected from MERS-CoV (the beta coronavirus or MERS), SARS-CoV (the beta coronavirus or SARS) and SARS- CoV-2 (COVID-19).

[42] 20. The method of point 15, wherein the RNA virus involved diseases are Middle East Respiratory Syndromes and Severe Acute Respiratory Syndromes.

[43] 21. The method of point 15, wherein the nucleoside analogue treatment has immunosuppressive effect, which stems from compromised B cell maturation in secondary lymphoid organs reducing the antibody-dependent enhancement (ADE) associated with RNA virus infections and maintenance the cellular immunity.

[44] 22. The method of point 15, wherein the nucleoside analogue treatment can block virus replication in all three stages of COVID-19 virus infection and associated diseases, wherein stage 1 is the initial 1-2 days with no sign of infection; in stage 2, the virus propagates and migrates down the respiratory tract along the conducting airways, and infects epithelial cells triggering a more robust innate immune response; and in stage 3, disease will develop pulmonary infiltrates and some of these will develop severe disease acute respiratory distress syndrome (ARDS) and the virus-specific antibodies can trigger more immune- pathological processes such as antibody-dependent enhancement and faulty Th2 reaction leading to virus infection of immune cells and expression of high level of inflammatory cytokines (cytokine storm). [45] 23. The method of point 15, wherein the nucleoside analogue treatment at the early periods of the RNA virus infection halt disease progression and prevent to enter the 3rd life threatening stage.

[46] 24. The method of point 15, wherein the administration of the nucleoside analogue to a human in the 2nd and 3rd stage of COVID-19 virus infection and associated diseases interferes with B cell maturation leads to antibody production and antibody-dependent enhancement (ADE).

[47] 25. The method of point 15, wherein the administration of the nucleoside analogue to a human counteracts with elevated immune cell proliferation and blocks high level of cytokine release.

[48] 26. The method of point 15, wherein the therapeutically effective amount of the nucleoside analogue is administered as add-on therapy to standard of care.

[49] 27. The method of point 15, wherein the therapeutically effective amount of the nucleoside analogue is administered subcutaneously or intravenously at 5-75 mg/m² or 0.1- 2.5 mg/kg dose for 3-14 days.

[50] 28. The method of point 15, wherein the RNA virus involved and associated diseases are selected from the group of upper respiratory tract viral infection showing nonspecific symptoms such as fever, fatigue, cough, anorexia, malaise, muscle pain, sore throat, dyspnea, nasal congestion, or headache; and/or have pneumonia with no signs of severe pneumonia and no need for supplemental oxygen; and/or have severe pneumonia; and/or infection related complications, such as acute respiratory distress syndrome (ARDS), acute respiratory failure, cardiovascular complications including venous and arterial thromboembolic diseases such as symptomatic acute pulmonary embolism, deep-vein thrombosis, stroke, ischemic stroke, myocardial infarction or systemic arterial embolism, acute liver injury, cytokine release syndrome including multisystem inflammatory syndrome and Kawasaki disease, septic shock, disseminated intravascular coagulation, venous thromboembolism, secondary infection, acute kidney injury, pancreatic injury, neurologic complications including hypoxic brain injury, where severe pneumonia can result in systemic hypoxia leading to brain damage and immune mediated injury that causes vascular leakage, activation of complement and coagulation cascade, dizziness, headache, acute cerebrovascular disease, impaired consciousness, transverse myelitis, acute hemorrhagic necrotizing encephalopathy, ancephalopathy ancephalitis, apilepsy, ataxia and peripheral such as hypogeusia, hyposmia, neuralgia, Guillian Barre syndrome, skeletal muscle injury, disseminated intravascular coagulation and end organ damage, rhabdomyolysis, pregnancy-related complications and secondary infections including aspergillosis, Acinetobacter baumannii , Klebsiella pneumoniae , Aspergillus flavus , Candida glabrata, Candida albicans , Enterobacter cloacae , Acinetobacter baumannii and Legionella pneumophillia.

[51] 29. The method of point 15, wherein the nucleoside analogue treatment at the early periods of the RNA virus infection prevents or halts RNA virus infection associated diseases or RNA virus infection associated disease progression and prevents to enter life threatening stage.

[52] 30. The nucleoside analogue of point 29 is 5-azacitidine.

[53] 31. A method for the treatment of post-acute syndromes of RNA viruses involved infections and associated diseases in a human by administering therapeutically effective amount of a nucleoside analogue.

[54] 32. The method of point 31, wherein the post-acute syndromes of RNA viruses involved infections includes highest risk for long-term pulmonary complications, including persistent diffusion impairment and radiographic pulmonary abnormalities (such as pulmonary fibrosis), thromboprophylaxis including segmental pulmonary embolism, intracardiac thrombus, thrombosed arteriovenous fistula and ischemic stroke, postural orthostatic tachycardia syndrome and inappropriate sinus tachycardia, chronic malaise, diffuse myalgia, depressive symptoms and non-restorative sleep, ischemic or hemorrhagic stroke, hypoxic-anoxic damage, posterior reversible encephalopathy syndrome and acute disseminated myelitis, myopathy and neuropathies, renal sequelae, subacute thyroiditis with clinical thyrotoxicosis, latent thyroid autoimmunity, new-onset Hashimoto’s thyroiditis or Graves’ disease, significant gastrointestinal and hepatobiliary sequelae, neurological complications, such as headache, altered mental status, encephalopathy, cranial nerve palsies, stroke, seizure, reduced reflexes, muscle weakness and Guillain Barre Syndrome. [55] 33. The method of point 31, wherein the nucleoside analogue is 5-azacitidine.

[56] 34. A method of treating the symptoms of short- and long-term adverse events and related diseases following immunization by vaccine to prevent RNA viruses involved infections and associated diseases in a human by administering therapeutically effective amount of a nucleoside analogue. [57] 35. The method of point 34, wherein the nucleoside analogue is 5-azacitidine.

[58] Provided here is a method of treating an RNA virus involved infections and associated diseases in a human by administering therapeutically effective amount of a nucleoside analogue. [59] The nucleoside analogue of the invention is selected from the group of methylation inhibitors, -cyano substituted nucleosides, flaviviral methyltransferase and rigid amphipathic nucleosides, ribavirin and other nucleoside synthesis inhibitors and rigid amphipathic nucleosides. [60] The methylation inhibitors of the present invention are 5-azacitidine, 5-aza-2'- deoxycytidine, 5-fluoro-2'-deoxycytidine, and zebularine; and -cyano substituted nucleosides are selected from -cyano substituted C-nucleoside derived from 4-aza-7,9- dideazaadenosine, 2’-C-methyladenosine, 7-deaza-2’-C-methyl-adenosine, phosphoramidate prodrug of 6-O-methyl -2’ -C-methylguanosine, 2’-C-methylcytidine, 2’-C-methyluridine, T - C-ethynyladenosine, Sofosbuvir, 7-deaza derivative of 2’ -C-ethynyladenosine, 2’-ethynyl modified derivative of 7-deaza derivative of 2’ -C-ethynyladenosine, isobutyryl ester prodrug of 2’-ethynyl modified derivative of 7-deaza derivative of T -C-ethynyladenosine, 4’-C- azidocytidine, Balapiravir, RO-9187, BCX4430, T-1106, 6-methyl-7-deazaadenosine, N6-(9- antranylmethyl) adenosine, N6-(l-pyrenylmethyl) adenosine, N6-benzyl-5’-0- triisopropyl silyl adenosine, N6-benzyl-5’-0-trityl adenosine, N6-benzyl-5’-0-tert- butyldimethylsilyl-adenosine, 2^,,5’-di-0-trityluridine, 3 ’ , 5 ’ -di -O-trityl uri di ne.

[61] The ribavirin and other nucleoside synthesis inhibitors of the present invention are selected from ribavirin, l-beta-D-ribofuranosyl-3-ethynyl-[l,2,4]triazole, 6-azauridine; and the rigid amphipathic nucleosides are selected from 5-(perylen-3-yl)ethynyl-arabino-uridine, 5-(perylen-3-yl)ethynyl-2’-deoxy-uridine, 5-(pyren-l-yl)ethynyl-20-deoxy-uridine.

[62] The nucleoside analogue disclosed here is 5-azacitidine.

[63] The therapeutically effective amount of a nucleoside analogue described here is 5-75 mg/m² or 0.1-2.5 mg/kg dose.

[64] RNA virus of the present invention is a positive-sense RNA virus (+ssRNA) and selected from the group of coronaviridae, and flaviviridae and togaviridae.

[65] The coronaviridae described here are selected from the group of 29E (alpha coronavirus), NL63 (alpha coronavirus), OC43 (beta coronavirus), HKU1 (beta coronavirus), MERS-CoV (the beta coronavirus that causes Middle East Respiratory Syndrome, or MERS), SARS-CoV (the beta coronavirus that causes Severe Acute Respiratory Syndrome, or SARS) and SARS-CoV-2 (the novel coronavirus that causes coronavirus disease 2019, or COVID- 19). [66] The coronaviridae of the present invention are selected from MERS-CoV (the beta coronavirus or MERS), SARS-CoV (the beta coronavirus or SARS) and SARS-CoV-2 (COVID-19).

[67] The RNA virus involved diseases disclosed here are Middle East Respiratory Syndromes and Severe Acute Respiratory Syndromes.

[68] The nucleoside analogue treatment of the present invention has immunosuppressive effect, which stems from compromised B cell maturation in secondary lymphoid organs reducing the antibody-dependent enhancement (ADE) associated with RNA virus infections and maintenance the cellular immunity. [69] The nucleoside analogue treatment of the present invention can block virus replication in all three stages of COVID-19 virus infection and associated diseases, wherein stage 1 is the initial 1-2 days with no sign of infection; in stage 2, the virus propagates and migrates down the respiratory tract along the conducting airways, and infects epithelial cells triggering a more robust innate immune response; and in stage 3, disease will develop pulmonary infiltrates and some of these will develop severe disease acute respiratory distress syndrome (ARDS) and the virus-specific antibodies can trigger more immune-pathological processes such as antibody-dependent enhancement and faulty Th2 reaction leading to virus infection of immune cells and expression of high level of inflammatory cytokines (cytokine storm).

[70] The nucleoside analogue treatment of the present invention at the early periods of the RNA virus infection halt disease progression and prevent to enter the 3rd life threatening stage.

[71] The administration of the nucleoside analogue to a human in the 2nd and 3rd stage of COVID-19 virus infection and associated diseases interferes with B cell maturation leads to antibody production and antibody-dependent enhancement (ADE). [72] The administration of the nucleoside analogue of the present invention to a human counteracts with elevated immune cell proliferation and blocks high level of cytokine release.

[73] The therapeutically effective amount of the nucleoside analogue of the invention is administered as add-on therapy to standard of care.

[74] The therapeutically effective amount of a nucleoside analogue of the present invention is administered subcutaneously or intravenously at 5-75 mg/m² or 0.1-2.5 mg/kg dose for 3-

14 days.

[75] The RNA virus involved and associated diseases disclosed here are selected from the group of upper respiratory tract viral infection showing nonspecific symptoms such as fever, fatigue, cough, anorexia, malaise, muscle pain, sore throat, dyspnea, nasal congestion, or headache; and/or have pneumonia with no signs of severe pneumonia and no need for supplemental oxygen; and/or have severe pneumonia; and/or infection related complications, such as acute respiratory distress syndrome (ARDS), acute respiratory failure, cardiovascular complications including venous and arterial thromboembolic diseases such as symptomatic acute pulmonary embolism, deep-vein thrombosis, stroke, ischemic stroke, myocardial infarction or systemic arterial embolism, acute liver injury, cytokine release syndrome including multisystem inflammatory syndrome and Kawasaki disease, septic shock, disseminated intravascular coagulation, venous thromboembolism, secondary infection, acute kidney injury, pancreatic injury, neurologic complications including hypoxic brain injury, where severe pneumonia can result in systemic hypoxia leading to brain damage and immune mediated injury that causes vascular leakage, activation of complement and coagulation cascade, dizziness, headache, acute cerebrovascular disease, impaired consciousness, transverse myelitis, acute hemorrhagic necrotizing encephalopathy, ancephalopathy ancephalitis, apilepsy, ataxia and peripheral such as hypogeusia, hyposmia, neuralgia, Guillian Barre syndrome, skeletal muscle injury, disseminated intravascular coagulation and end organ damage, rhabdomyolysis, pregnancy-related complications and secondary infections including aspergillosis, acinetobacter baumannii, klebsiella pneumoniae, aspergillus flavus, Candida glabrata, Candida albicans, enterobacter cloacae, acinetobacter baumannii and legionella pneumophillia. [76] The nucleoside analogue treatment of the present invention at the early periods of the

RNA virus infection prevents or halts RNA virus infection associated diseases or RNA virus infection associated disease progression and prevents to enter life threatening stage.

[77] The nucleoside analogue of the invention is 5-azacitidine.

[78] The treatment of post-acute syndromes of RNA viruses involved infections and associated diseases in a human by administering therapeutically effective amount of a nucleoside analogue.

[79] The post-acute syndromes of RNA viruses involved infections of the invention includes but not limited to highest risk for long-term pulmonary complications, including persistent diffusion impairment and radiographic pulmonary abnormalities (such as pulmonary fibrosis), thromboprophylaxis including segmental pulmonary embolism, intracardiac thrombus, thrombosed arteriovenous fistula and ischemic stroke, postural orthostatic tachycardia syndrome and inappropriate sinus tachycardia, chronic malaise, diffuse myalgia, depressive symptoms and non-restorative sleep, ischemic or hemorrhagic stroke, hypoxic-anoxic damage, posterior reversible encephalopathy syndrome and acute disseminated myelitis, myopathy and neuropathies, renal sequelae, subacute thyroiditis with clinical thyrotoxicosis, latent thyroid autoimmunity, new-onset Hashimoto’s thyroiditis or Graves’ disease, significant gastrointestinal and hepatobiliary sequelae, neurological complications, such as headache, altered mental status, encephalopathy, cranial nerve palsies, stroke, seizure, reduced reflexes, muscle weakness and Guillain Barre Syndrome.

[80] A method provided here is the treatment of the symptoms of short and long term adverse events and related diseases following immunization by vaccine to prevent RNA viruses involved infections and associated diseases in a human by administering therapeutically effective amount of a nucleoside analogue.

DETAILED DESCRIPTION OF THE INVENTION

[81] RNA virus induced diseases are complex pathologies that affect multiple cell types, cellular factors, and mechanisms. Accordingly, the effective therapy of COVID-19 must address multiple segments of the pathology. COVID-19 therapies that proved to be ineffective in clinical trials are usually very specific for certain factors or mechanisms.

[82] Promising drug targets include nonstructural proteins (e.g., 3-chymotrypsin-like protease, papain-like protease, RNA-dependent RNA polymerase), which share homology with other novel coronaviruses (nCoVs). Additional drug targets include viral entry and immune regulation pathways.

[83] Anti-malaria and autoimmune disease therapeutics include chloriquine and hydroxychloroquine altering optimal lysosomal pH in antigen-presenting cells and block TLR9 pathway in dendritic cells, which is involved in inflammation. Despite these promising results of the clinical trials conducted so far, the studied had several major limitations that were coupled with concerns of additive cardiotoxicity with combination therapy. Both agents can cause rare and serious adverse effects, including QTc prolongation, hypoglycemia, neuropsychiatric effects, and retinopathy.

[84] Antiretroviral therapeutics including lopinavir and ritonavir that are protease inhibitors that block cleavage of a retrovirus specific protein precursor, which is essential for efficient virus replication. Current clinical data suggest a limited role for lopinavir/ritonavir in COVID- 19 treatment. Adverse effects of ritonavir/1 opinavir include gastrointestinal distress such as nausea and diarrhea and hepatotoxicity. In patients with COVID-19, these adverse effects may be exacerbated by combination therapy or viral infection because approximately 20% to 30% of patients have elevated transaminases at presentation with COVID-19. Approximately 50% of ritonavir/lopinavir patients experienced an adverse effect and 14% of patients discontinued therapy due to gastrointestinal adverse effects (Sanders et.al., 2020).

[85] Anti -Influenza A and B therapeutics such as umifenovir which is an inhibitor of virus envelope and cell membrane fusion resulting in impaired entry of cells and oseltamir which is a glycosylase-specific inhibitor, which is essential for releasing of assembled viruses from the infected cells. Oseltamir has no role in the management of COVID-19 once influenza has been excluded. Observational data cannot establish the efficacy of umifenovir for COVID-19.

[86] Anti-Ebola therapeutics including remdesivir, an investigational compound is a modified ribonucleoside that inhibits virus RNA synthesis by causing premature termination of RNA synthesis. This compound thought to be one of the best options for treating Covid-19, however it is failed to have any effect in the first full trial.

[87] Anticytokine or immunomodulatory therapeutics that are monoclonal antibodies directed against key inflammatory cytokines or other aspects of the innate immune response represent another potential class of adjunctive therapies for COVID-19. The rationale for their use is that the underlying pathophysiology of significant organ damage in the lungs and other organs is caused by an amplified immune response and cytokine release, or “cytokine storm”. Tocilizumab, a monoclonal antibody IL-6 receptor antagonist to treat cytokine release syndrome following chimeric antigen receptor T-cell therapy. Several clinical trials using tocilizumab, alone or in combination, in patients with COVID-19 with severe pneumonia are ongoing. Sarilumab (IL-6 receptor antagonist), bevacizumab (anti-vascular endothelial growth factor medication), fmgolimod (immunomodulator) and eculizumab (antibody inhibiting terminal complement) are under investigation.

[88] Until now, 13 COVID-19 vaccines were authorized for emergency use by at least one national regulatory authority for public use: two RNA vaccines (the Pfizer-BioNTech vaccine and the Moderna vaccine), five conventional inactivated vaccines (BBIBP-CorV, CoronaVac, Covaxin, WIBP-CorV and CoviVac), four viral vector vaccines (Sputnik V, the Oxford- AstraZeneca vaccine, Convidecia, and the Johnson & Johnson vaccine), and two protein subunit vaccines (EpiVacCorona and RBD-Dimer). Some people who received the vaccine and were later exposed to the virus developed more severe disease than those who had not been vaccinated. This immune backfiring is called immune enhancement, which might be caused two different ways such as antibody-dependent enhancement (ADE) and cell-based enhancement (CBE) process.

[89] Although many vaccines are still being tested in clinical trials and community-wide (mass) vaccinations have been started recently, there is some information about the mid- and long-term side effects of COVID-19 vaccines. Some blood coagulation abnormalities including abnormal clot formation appeared in brain and abdomen within two weeks of receiving Oxford-AstraZeneca vaccine (D’Agostino et al., 2021; Wolf et al., 2021). Autoimmune reactions to vaccinations may rarely be induced in predisposed individuals by molecular mimicry or bystander activation mechanisms (Segal & Shoenfeld, 2018). Autoimmune reactions reliably considered vaccine-associated, include Guillain-Barre syndrome after 1976 swine influenza vaccine, immune thrombocytopenic purpura after measles/mumps/rubella vaccine, and myopericarditis after smallpox vaccination, whereas the suspected association between hepatitis B vaccine and multiple sclerosis has not been further confirmed, even though it has been recently reconsidered, and the one between childhood immunization and type 1 diabetes seems by now to be definitively gone down (Salemi & D’Amelio, 2010). In case of COVID-19 vaccine, this matter is further complicated by the nucleic acid formulation (Aldosari et al., 2021) and the accelerated development process imposed by the emergency pandemic situation. Currently, lipid nanoparticle-formulated mRNA vaccines coding for the SARS-CoV-2 full-length spike protein have shown the highest level of evidence according to the efficacy and safety profile in clinical trials, being therefore authorized and recommended for use (Aldosari et al., 2021). Although the results from phase I and II/III studies have not raised serious safety concerns, the time of observation was extremely short, and the target population not defined. Reported local and systemic adverse events seemed to be dose-dependent and more common in participants aged under 55 years. These results presumably depend on the higher reactogenicity occurring in younger people that may confer greater protection towards viral antigens but also predispose to a higher burden of immunological side effects. The reactogenicity of COVID-19 mRNA vaccine in individuals suffering from immune-mediated diseases and having therefore a pre-existent dysregulation of the immune response has not been investigated. It is hypothesized that immunosuppressive agents pre-scribed to these patients mitigate or even prevent side effects related to vaccine immunogenicity. Besides the mechanism of molecular mimicry, mRNA vaccines may give rise to a cascade of immunological events eventually leading to the aberrant activation of the innate and acquired immune system. [90] An RNA vaccine contains RNA which, when introduced into a tissue, acts as messenger RNA (mRNA) to cause the cells to build the foreign protein and stimulate an adaptive immune response which teaches the body how to identify and destroy the corresponding pathogen or cancer cells. RNA vaccines often, but not always, use nucleoside- modified messenger RNA. The delivery of mRNA is achieved by a coformulation of the molecule into lipid nanoparticles which protect the RNA strands and help their absorption into the cells. Adenovirus vector vaccines are examples of non-replicating viral vector vaccines, using an adenovirus shell containing DNA that encodes a SARS-CoV-2 protein. The viral vector-based vaccines against COVID-19 are non-replicating, meaning that they do not make new virus particles, but rather produce only the antigen which elicits a systemic immune response. Inactivated vaccines consist of virus particles that have been grown in culture and then are killed using a method such as heat or formaldehyde to lose disease producing capacity, while still stimulating an immune response. Subunit vaccines present one or more antigens without introducing whole pathogen particles. The antigens involved are often protein subunits but can be any molecule that is a fragment of the pathogen.

[91] There are increasing reports of prolonged effects after acute COVID-19 disease. Post acute COVID-19 syndrome characterized by persistent symptoms and/or delayed or long-term complications beyond 4 weeks from the onset of symptoms. Post-acute syndromes can be divided into two categories: (1) subacute or ongoing symptomatic COVID-19, which includes symptoms and abnormalities present from 4-12 weeks beyond acute COVID-19; and (2) chronic or post-COVID-19 syndrome, which includes symptoms and abnormalities persisting or present beyond 12 weeks of the onset of acute COVID-19 and not attributable to alternative diagnoses. Potential mechanisms include virus-specific pathophysiologic changes; immunologic aberrations and inflammatory damage in response to the acute infection; and expected sequelae of post-critical illness. Syndromes includes but not limited to highest risk for long-term pulmonary complications, including persistent diffusion impairment and radiographic pulmonary abnormalities (such as pulmonary fibrosis), thromboprophylaxis including segmental pulmonary embolism, intracardiac thrombus, thrombosed arteriovenous fistula and ischemic stroke, postural orthostatic tachycardia syndrome and inappropriate sinus tachycardia, chronic malaise, diffuse myalgia, depressive symptoms and non-restorative sleep, ischemic or hemorrhagic stroke, hypoxic-anoxic damage, posterior reversible encephalopathy syndrome and acute disseminated myelitis, myopathy and neuropathies, renal sequelae, subacute thyroiditis with clinical thyrotoxicosis, latent thyroid autoimmunity, new-onset Hashimoto’s thyroiditis or Graves’ disease, significant gastrointestinal and hepatobiliary sequelae, neurological complications, such as headache, altered mental status, encephalopathy, cranial nerve palsies, stroke, seizure, reduced reflexes, muscle weakness and Guillain Barre Syndrome (Nalbandian et.al.,2021).

[92] Survivors of acute COVID-19 may be at increased risk of infections with bacterial, fungal (pulmonary aspergillosis) or other pathogens. [93] Aspergillosis is frequently associated with RNA virus-induced including influenza, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and COVID-19-associated pulmonary aspergillosis (CAPA) as a secondary or super-infections. Voriconazole is recommended as a primary treatment (Neely et al. 2017). Other therapies include liposomal Amphotericin B (Chapman et al. 2011), isavuconazole (Miceli et al. 2015), echinocandins (Denning et al. 20012) (micafungin or caspofungin) can be also used. Combination antifungal therapy with voriconazole and an echinocandin may be considered. Antifungal treatment must be continued for a minimum of 6-12 weeks.

[94] The currently available antifungal drugs have significant limitations, including the potential for life-threatening drug interactions and serious side effects such as kidney or liver toxicity, and with reports that severe COVID-19 infection alone can cause damage to multiple organ systems including the liver, kidney and heart, these safety concerns become even more problematic. Compounding the problem further, resistance to currently approved medicines has been developing in some fungal pathogens, rendering these antifungal drugs not only unsafe, but ineffective in many cases (Kennedy 2020; Verweij et al. 2020).

[95] Currently, there is no evidence from randomized clinical trials that any potential therapy improves outcomes in patients with either suspected or confirmed COVID-19. There are no clinical trial data supporting any prophylactic therapy. More than 300 active clinical treatment trials are underway. [96] As used in the present specification, the following words and phrases are generally intended to have the meanings as set forth below, except to the extent that the context in which they are used indicates otherwise.

[97] ADMINISTERING: As used herein, “administering” means to provide a compound or other therapy, remedy, or treatment such that an individual internalizes a compound. [98] CO-ADMINISTER: As used herein, “co-administer“ and “co-administration” and variants thereof mean the administration of at least two drugs to a patient either subsequently, simultaneously, or consequently proximate in time to one another (e.g., within the same day, or week or period of 30 days, or sufficiently proximate that each of the at least two drugs can be simultaneously detected in the blood plasma). When co-administered, two or more active agents can be co-formulated as part of the same composition or administered as separate formulations. This also may be referred to herein as “concomitant” administration or variants thereof.

[99] TREAT, TREATING, OR TREATMENT: As used herein, the term “treat,” “treating”, or “treatment” means the administration of therapy to an individual who already manifests at least one symptom of a disease or condition or who has previously manifested at least one symptom of a disease or condition. For example, “treating” can include alleviating, abating or ameliorating a disease or condition symptoms, preventing additional symptoms, ameliorating the underlying metabolic causes of symptoms, inhibiting the disease or condition, e.g., arresting the development of the disease or condition, relieving the disease or condition, causing regression of the disease or condition, relieving a condition caused by the disease or condition, or stopping the symptoms of the disease or condition. For example, the term “treating” in reference to a disorder means a reduction in severity of one or more symptoms associated with that particular disorder. Therefore, treating a disorder does not necessarily mean a reduction in severity of all symptoms associated with a disorder and does not necessarily mean a complete reduction in the severity of one or more symptoms associated with a disorder.

[100] IN NEED OF TREATMENT and IN NEED THEREOF: As used herein, “in need of treatment” and “in need thereof’ when referring to treatment are used interchangeably to mean a judgment made by a caregiver (e.g. physician, nurse, nurse practitioner, etc.) that an individual requires or will benefit from treatment. This judgment is made based on a variety of factors that are in the realm of a caregiver’s expertise, but that includes the knowledge that the individual is ill, or will become ill, as the result of a disease, condition or disorder that is treatable by the compounds of the invention. Accordingly, the compounds of the invention can be used in a protective or preventive manner; or compounds of the invention can be used to alleviate, inhibit or ameliorate the disease, condition or disorder.

[101] THERAPEUTICALLY EFFECTIVE AMOUNT: As used herein, "therapeutically effective amount" of an agent, compound, drug, composition or combination is an amount which is nontoxic and effective for producing some desired therapeutic effect upon administration to a subject or patient (e.g., a human subject or patient). The precise therapeutically effective amount for a subject may depend upon, e.g., the subject’s size and health, the nature and extent of the condition, the therapeutics or combination of therapeutics selected for administration, and other variables known to those of skill in the art. The effective amount for a given situation is determined by routine experimentation and is within the judgment of the clinician. In some embodiments, the therapeutically effective amount is the standard dose.

[102] DOSE: As used herein, “dose” means a quantity of an active ingredient given to the individual for treating or preventing the disease or disorder at one specific time. [103] STANDARD DOSE: As used herein, “standard dose” means the dose of the active ingredient that is given to the individual for treating or preventing the disease or disorder. The target dose may vary depending on the nature and severity of the disease to be treated.

[104] When an integer is used in a method disclosed herein, the term “about” can be inserted before the integer.

[105] Throughout this specification, unless the context requires otherwise, the word “comprise”, or variations such as “comprises” or “comprising” will be understood to imply the inclusion of a stated step or element or integer or group of steps or elements or integers but not the exclusion of any other step or element or integer or group of elements or integers. [106] Those skilled in the art will appreciate that the invention(s) described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention(s) includes all such variations and modifications. The invention(s) also includes all the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations or any two or more of said steps or features unless specifically stated otherwise.

[107] The present invention(s) is not to be limited in scope by the specific embodiments described herein, which are intended for the purpose of exemplification only. Functionally equivalent products, compositions, and methods are clearly within the scope of the invention(s), as described herein. [108] It is appreciated that certain features of the invention(s), which are, for clarity, described in the context of separate embodiments, can also be provided in combination in a single embodiment. Conversely, various features of the invention(s), which are, for brevity, described in the context of a single embodiment, can also be provided separately or in any suitable subcombination. For example, a method that recites prescribing and/or administering a given compound can be separated into two methods; one method reciting prescribing the compound and the other method reciting administering the compound. In addition, for example, a method that recites prescribing a compound and a separate method of the invention reciting administering a compound can be combined into a single method reciting prescribing and/or administering the compound. [109] Provided are compounds and method for the treatment of RNA virus involved diseases.

[110] In an embodiment, the compounds are nucleoside analogues. [111] In an embodiment, nucleoside analogues are selected from the group of methylation inhibitors, -cyano substituted nucleosides, flaviviral methyltransferase and rigid amphipathic nucleosides.

[112] In an embodiment, the methylation inhibitors are 5-azacitidine, 5-aza-2'-deoxycitidine, 5-fluoro-2'-deoxycytidine, and zebularine.

[113] In an embodiment, the -cyano substituted nucleosides are selected from -cyano substituted C-nucleoside derived from 4-aza-7,9-dideazaadenosine, 2’-C-methyladenosine, 7- deaza-2’-C-methyl-adenosine, phosphoramidate prodrug of 6-O-methyl -2’ -C- methylguanosine, 2’ -C-m ethyl cyti dine, 2’-C-methyluridine, 2’-C-ethynyladenosine, Sofosbuvir, 7-deaza derivative of 2’-C-ethynyladenosine, 2’-ethynyl modified derivative of 7- deaza derivative of 2’-C-ethynyladenosine, isobutyryl ester prodrug of 2’-ethynyl modified derivative of 7-deaza derivative of T -C-ethynyl adenosine, 4’-C-azidocytidine, Balapiravir, RO-9187, BCX4430, T-1106, 6-methyl-7-deazaadenosine, N6-(9-antranylmethyl) adenosine, N6-(l-pyrenylmethyl) adenosine, N6-benzyl-5’-0-triisopropylsilyl adenosine, N6-benzyl-5’- O-trityl adenosine, N6-benzyl-5’-0-tert-butyldimethylsilyl-adenosine, 2^,,5’-di-0-trityluridine, 3 ’ , 5 ’ -di -O -trityluri dine,

[114] In an embodiment, the nucleoside analogues are ribavirin and other nucleoside synthesis inhibitors.

[115] In an embodiment, the ribavirin and other nucleoside synthesis inhibitors are selected from ribavirin, l-beta-D-ribofuranosyl-3-ethynyl-[l,2,4]triazole, 6-azauridine.

[116] In an embodiment, the rigid amphipathic nucleosides are selected from 5-(perylen-3- yl)ethynyl-arabino-uridine, 5-(perylen-3-yl)ethynyl-2’-deoxy-uridine, 5-(pyren-l-yl)ethynyl- 20-deoxy-uridine.

[117] In an embodiment, the compound is 5-azacitidine.

[118] 5-azacitidine is a pyrimidine nucleoside analog of cyti dine. 5-azacitidine is 4-amino- 1- P-D-ribofuranosyl-s-triazin-2(lH)-one. The structural formula is as follows:

[119] The empirical formula is C H N O . The molecular weight is 244. 5-azacitidine is a white to off-white solid. It is marketed under the trade name of VIDAZA® and supplied in a sterile form for reconstitution as a suspension for subcutaneous injection or reconstitution as a solution with further dilution for intravenous infusion. Vials of VIDAZA® contain 100 mg of 5-azacitidine and 100 mg mannitol as a sterile lyophilized powder.

[120] 5-azacitidine can be incorporated into RNA by RNA polymerases including both DNA- and RNA-dependent polymerases. Since viral RNA synthesis uses the same cellular ribonucleotide pool as cellular mRNAs, 5-azacitidine is also built in viral genomes interfering with virus replication, transcription and translation. 5-azacitidine blocks mouse corona virus replication by 2 orders of magnitude in tissue cultures (Graepel et.al; 2017). RNA virus studies with influenza H5N1 virus demonstrated that acute lung injury score was significantly decreased in mice after 5-azacitidine treatment. More specifically, lung edema was reduced, the wet-to-dry weight ratio of lung tissue was improved, and survival rate of 5-azacitidine- treated animals was significantly higher than in control groups.

[121] In and embodiment, 5-azacitidine is a DNA hypomethylating agent incorporating into the replicating DNA and then recognizing by DNA methyltrasf erases (DNMTs) conducting epigenetic modification of DNA. 5-azacitidine generates covalent bonds with DNMTs resulting in trapped enzymes that ultimately lead to rapid enzyme depletion and DNA hypomethylation. 5-azacitidine is mostly involved in DNA hypomethylation by direct blocking of DNMTs.

[122] 5-azacitidine is ribonucleoside analogues and mostly incorporated into RNA (~ 90%). Only a small portion (-10%) of 5-azacitidine is built into DNA. 5-azacitidine carrying non coding RNAs is implicated in DNA hypomethylation and work through an RNA-mediated mechanism. Moreover, 5-azacitidine inhibits the accumulation of ribosomal RNAs and formation of the 80S ribosomal subunit in cytoplasm. Disaggregation of polyribosomes was also observed in 5-azacitidine-treated cells that explains the compromised protein synthesis. In the light of these data, present invention directed to the therapeutic application of 5- azacitidine in other diseases such as RNA virus mediated devastating infections.

[123] In an embodiment, 5-azacitidine works through an RNA-mediated mechanism incorporating into the replicating virus RNA and interferes with the subsequent viral transcription, translation, and replication.

[124] In an embodiment, the host cells’ translation machinery is also (transiently) compromised by 5-azacitidine, therefore, the cytokine storm induced cell proliferation (CBE) can be attenuated. [125] In embodiment, 5-azacitidine is an efficient epigenetic compound and incorporates into DNA and reactivates DNA methylation-inactivated cellular genes that encode protective factors.

[126] In an embodiment, 5-azacitidine inhibits antibody production by blocking B cell maturation in secondary lymphoid organs providing treatment option for reducing virus- induced antibody-dependent enhancement (ADE), which is a risk factor for COVID-19.

[127] B cell-mediated immunity is not necessarily beneficial for all virus-associated diseases. For example: antibody-dependent enhancement (ADE), sometimes referred to disease enhancement, occurs when antibodies facilitate virus entry into cells that do not have the usual receptors on their surfaces that viruses use to gain entry. In case of ADE, immune cells with antibody binding Fc receptors internalize antibody coated viruses. RNA virus entry into immune cells induces elevated expression of inflammatory cytokines (Cytokine storm), which leads to fatal tissue damage and ultimately death.

[128] In and embodiment, 5-azacitidine is a dual-acting agent blocking virus replication and IgG production: (a) after blocking agent treatment, RNA-dependent polymerases incorporate modified ribonucleotides into viral RNA leading to blocked virus replication and production and (b) at the same time, dual-acting agent interferes with B cell development leading to reduced antibody production, which acts against cytokine storm and other permanent adverse effects (Figure 2).

[129] These observations lead to the conclusion that 5-azacitidine treatment can be beneficial for RNA virus infected individuals.

[130] In an embodiment, 5-azacitidine treatment have immunosuppressive effect, which stems from compromised B cell maturation in secondary lymphoid organs reducing the antibody-dependent enhancement (ADE) associated with RNA virus infections and maintenance the cellular immunity.

[131] In an embodiment, 5-azacitidine is a ribonucleoside analogue are efficiently transported through the membrane with significantly decreased cytotoxicity.

[132] In an embodiment, 5-azacitidine treatment counteracts with blood coagulation and reduces thrombogenesis by reducing platelet number and platelet activation.

[133] In an embodiment, 5-azacitidine treatment reduces thrombogenesis by activating expression of protein factors are involved in fibrinolysis.

[134] In an embodiment, 5-azacitidine treatment triggers Treg cell biogenesis by hypom ethylating genomic region governs Foxp3 gene expression. [135] In an embodiment, 5-azacitidine hinders generation of critically high antibody level leading to antibody-dependent enhancement (ADE).

[136] In an embodiment, 5-azacitidine an effective anti-covid and post-covid drug because it exerts its effect independently of the actual RNA virus or its mutant derivatives (i.e., virus progeny).

[137] In an embodiment, present invention provides a method for the treatment of RNA viruses involved infections and associated diseases in a human administering therapeutically effective amount of 5-azacitidine.

[138] In an embodiment, present invention provides a method for the treatment of post-acute syndromes of RNA viruses involved infections and associated diseases in a human administering therapeutically effective amount of 5-azacitidine.

[139] In an embodiment, post-acute syndromes of RNA viruses involved infections includes but not limited to highest risk for long-term pulmonary complications, including persistent diffusion impairment and radiographic pulmonary abnormalities (such as pulmonary fibrosis), thromboprophylaxis including segmental pulmonary embolism, intracardiac thrombus, thrombosed arteriovenous fistula and ischemic stroke, postural orthostatic tachycardia syndrome and inappropriate sinus tachycardia, chronic malaise, diffuse myalgia, depressive symptoms and non-restorative sleep, ischemic or hemorrhagic stroke, hypoxic-anoxic damage, posterior reversible encephalopathy syndrome and acute disseminated myelitis, myopathy and neuropathies, renal sequelae, subacute thyroiditis with clinical thyrotoxicosis, latent thyroid autoimmunity, new-onset Hashimoto’s thyroiditis or Graves’ disease, significant gastrointestinal and hepatobiliary sequelae, neurological complications, such as headache, altered mental status, encephalopathy, cranial nerve palsies, stroke, seizure, reduced reflexes, muscle weakness and Guillain Barre Syndrome.

[140] In an embodiment, present invention provides a method for the treatment of the symptoms of short- and long-term adverse events and related diseases following immunization by vaccine to prevent RNA viruses involved infections and associated diseases in a human administering therapeutically effective amount of 5-azacitidine.

[141] In an embodiment, therapeutically effective amount of 5-azacitidine and its derivative is 5-75 mg/m² dose or 0.1-2.5 mg/kg.

[142] In an embodiment, the therapeutically effective amount of 5-azacitidine is administered subcutaneously or intravenously for 3-14 days. [143] In an embodiment, the present invention provides a method for the treatment of RNA viruses involved infections and associated diseases in a human co-administering therapeutically effective amount of 5-azacitidine as an add-on therapy to standard of care.

[144] In an embodiment, RNA viruses are positive-sense RNA viruses (+ssRNA).

[145] In an embodiment, said (+) ssRNA type viruses are coronaviridae, such as infectious bronchitis virus, mouse hepatitis virus and flaviviridae, such as yellow fever virus, tick-borne encephalitis virus, Dengue virus type 2 and togaviridae, such as sindbis virus, semliki forest virus.

[146] In an embodiment, said corona viruses are 29E (alpha coronavirus), NL63 (alpha coronavirus), OC43 (beta coronavirus), HKU1 (beta coronavirus), MERS-CoV (the beta coronavirus that causes Middle East Respiratory Syndrome, or MERS), SARS-CoV (the beta coronavirus that causes severe acute respiratory syndrome, or SARS) and SARS-CoV-2 (the novel coronavirus that causes coronavirus disease 2019, or COVID-19).

[147] In an embodiment, said corona viruses are MERS-CoV (the beta coronavirus or MERS), SARS-CoV (the beta coronavirus or SARS) and SARS-CoV-2 (COVID-19).

[148] In an embodiment, said RNA virus involved diseases are Middle East Respiratory Syndromes and severe acute respiratory syndromes.

[149] In an embodiment, patients infected by said RNA viruses have uncomplicated upper respiratory tract viral infection showing nonspecific symptoms such as fever, fatigue, cough, anorexia, malaise, muscle pain, sore throat, dyspnea, nasal congestion, or headache.

[150] In an embodiment, patients infected by said RNA viruses have pneumonia with no signs of severe pneumonia and no need for supplemental oxygen.

[151] In an embodiment, patients infected by said RNA viruses have severe pneumonia.

[152] In an embodiment, complications, such as acute respiratory distress syndrome (ARDS), acute respiratory failure, cardiovascular complications, acute liver injury, cytokine release syndrome, septic shock, disseminated intravascular coagulation, venous thromboembolism, secondary infection, acute kidney injury, pancreatic injury, neurologic complications, rhabdomyolysis, pregnancy-related complications could develop in patients infected by said RNA viruses.

[153] In an embodiment, 5-azacitidine treatment can block virus replication in all three stages of COVID-19 virus infection and associated diseases.

[154] In an embodiment, 5-azacitidine treatment at the early periods of infection halt disease progression and prevent to enter the 3rd life threatening stage. [155] In an embodiment, administration of 5-azacitidine to a human in the 3rd stage of COVID-19 virus infection and associated diseases interferes with B cell maturation leads to antibody production and ADE.

[156] In an embodiment, administration of 5-azacitidine to a human counteracts with elevated immune cell proliferation and blocks high level of cytokine release.

[157] Differentially expressed genes were identified in SARS-CoV-2 infected lung tissues (Ackermann et al. 2020) and a number of genes are known for being targets of DNA methylation-mediated gene silencing (Vaidya et al. 2016). Since 5-azacitidine is a hypomethylating agent, this leads to the conclusion that these genes might be reactivated or protected from disease-promoting DNA hypermethylation after 5-azacitidine treatment.

[158] In an embodiment, the treatment using 5-azacitidine provokes thrombocytopenia (i.e., low platelet number), which counteracts with virus-induced thrombosis by reducing the number of that cell type that is mainly involved in coagulation of blood.

[159] In an embodiment, the treatment using 5-azacitidine inhibits infiltration of CD+ T cells in perivascular regions (Ackermann el al. 2020) and high level expression of cytokines and chemokines (i.e., cytokine storm) (Ye et al. 2020).

[160] 5-azacitidine is known for its ability to inhibit cytidine methylation and has an effect on gene expression (Jones et al. 20019). Studies on 5-azacitidine have indicated that this well- known DNA methyltransferase inhibitor could disturb fungal development (Wilkinson et al. 2011) and blocking aflatoxin (AF) production, which is a mutagen. In addition to gene expression modification, 5-azacitidine can cause changes in the structure of cellular and organelle membranes that interfere with normal fungal development.

[161] These observations lead to the conclusion that 5-azacitidine have therapeutic potential in aspergillosis in context of RNA virus infections.

[162] In an embodiment, 5-azacitidine has antifungal effect.

[163] In an embodiment, the antifungal effect of 5-azacitidine is an additive effect besides of blocking virus replication and suppressing B cell proliferation.

[164] In an embodiment, 5-azacitidine treatment can be superior to current anti-fungal drugs employed in the context of RNA virus-related diseases since it effects pathogeneses at pivotal points. Accordingly, 5-azacitidine (1) as ribonucleoside analogue, inhibits RNA virus replication by incorporating into viral RNA and interfering with transcription; (2) can act as a DNA hypomethylating agent by covalently binding DNA methyltransferases, and reactivating anti-viral genes and genes are involved in antigen presentation; (3) compromises B cell development leading to moderate antibody level, which might counteract with antibody- dependent enhancement (ADE); (4) reduces infiltration of neutrophils into the inflamed lung; (5) interferes with fungal lifecycle and prevents fungus-induced death of pneumocytes and overexpression of tissue factor by capillary endothelial cells; (6) induces transient decrease in platelet number after the first cycle of treatment, which reduces the chance of cloth formation leading to cardiovascular complications and (7) reactivates set of genes with anti -thrombotic effect. (8) promotes differentiation of Treg cells, which act as anti-inflammatory and anti- autoimmune regulatory T cells.

[165] In an embodiment, 5-azacitidine treatment can be effective in treatment of RNA virus- induced post-acute symptoms since it targets pivotal points of the pathogenesis. Accordingly, 5-azacitidine (1) as ribonucleoside analogue, inhibits progeny RNA virus replication by incorporating into viral RNA and interfering with transcription; (2) can act as a DNA and RNA hypomethylating agent by inactivating DNA and RNA methyltransferases, and reactivating anti-viral genes and genes are involved in antigen presentation; (3) compromises B cell development leading to moderate antibody level, which might counteract with antibody-dependent enhancement (ADE); (4) reduces infiltration of neutrophils into the inflamed lung; (5) interferes with fungal lifecycle and prevents fungus-induced death of pneumocytes and overexpression of tissue factor by capillary endothelial cells; (6) induces transient decrease in platelet number after the first cycle of treatment, which reduces the chance of cloth formation leading to cardiovascular complications and (7) reactivates set of genes with anti -thrombotic effect; (8) triggers Treg cell differentiation leading suppressed inflammation and subsequent autoimmune processes.

[166] In an embodiment, the mid- and long-term side effects of COVID-19 vaccines that can be ameliorated by 5-azacitidine treatment.

[167] In an embodiment, the 5-azacitidine can intercalate in RNA and interfere with platelet activation, with is prerequisite of effective blood coagulation and act on endothelial cells covering the inner surface of blood vessels by inhibiting activation and release of coagulation promoting factors.

[168] In an embodiment, the targeted inhibition of DNA methylation by 5-azacitidine increases the fibrinolysis leading to compromised thrombogenesis.

[169] In an embodiment, 5-azacitidine possess anti-inflammatory effect ameliorating autoimmune diseases by affecting B cell differentiation.

[170] In an embodiment, 5-azacitidine as a DNA hypomethylating agent can trigger Treg cell differentiation, which cells counteract with pathology of autoimmune diseases. Examples

Example 1: Theoretical mechanism of action of 5-azaciditine

[171] 5-azacitidine as a ribonucleoside analogue are efficiently transported through the membrane with significantly decreased cytotoxicity, therefore 5-azacitidine is an efficient epigenetic compound and incorporates into DNA and reactivates DNA methylation- inactivated cellular genes that encode protective factors. 5-azacitidine acts as a dual-acting agent blocking virus replication and IgG production: (a) after blocking agent treatment, RNA- dependent polymerases incorporate modified ribonucleotides into viral RNA leading to blocked virus replication and production and (b) at the same time, dual-acting agent interferes with B cell development leading to reduced antibody production, which acts against cytokine storm and other permanent adverse effects (Figure 2).

[172] Theoretical mechanism of action of 5-azacitidine provides effective treatment for RNA virus involved infection and related diseases to counteract with blood coagulation, reduce thrombogenesis by reducing platelet number and platelet activation, reduce thrombogenesis by activating expression of protein factors involved in fibrinolysis, trigger Treg cell biogenesis by hypomethylating genomic region governs Foxp3 gene expression.

[173] In an embodiment, 5-azacitidine hinders generation of critically high antibody level leading to antibody-dependent enhancement (ADE).

[174] 5-azacitidine (1) as ribonucleoside analogue, inhibits RNA virus replication by incorporating into viral RNA and interfering with transcription; (2) can act as a DNA hypomethylating agent by covalently binding DNA methyltransferases, and reactivating anti viral genes and genes are involved in antigen presentation; (3) compromises B cell development leading to moderate antibody level, which might counteract with antibody- dependent enhancement (ADE); (4) reduces infiltration of neutrophils into the inflamed lung; (5) interferes with fungal lifecycle and prevents fungus-induced death of pneumocytes and overexpression of tissue factor by capillary endothelial cells; (6) induces transient decrease in platelet number after the first cycle of treatment, which reduces the chance of cloth formation leading to cardiovascular complications and (7) reactivates set of genes with anti -thrombotic effect. (8) promotes differentiation of Treg cells, which act as anti-inflammatory and anti- autoimmune regulatory T cells.

[175] 5-azacitidine treatment can be effective in treatment of RNA virus-induced post-acute symptoms since it targets pivotal points of the pathogenesis. Accordingly, 5-azacitidine (1) as ribonucleoside analogue, inhibits progeny RNA virus replication by incorporating into viral RNA and interfering with transcription; (2) can act as a DNA and RNA hypomethylating agent by inactivating DNA and RNA methyltransferases, and reactivating anti-viral genes and genes are involved in antigen presentation; (3) compromises B cell development leading to moderate antibody level, which might counteract with antibody-dependent enhancement (ADE); (4) reduces infiltration of neutrophils into the inflamed lung; (5) interferes with fungal lifecycle and prevents fungus-induced death of pneumocytes and overexpression of tissue factor by capillary endothelial cells; (6) induces transient decrease in platelet number after the first cycle of treatment, which reduces the chance of cloth formation leading to cardiovascular complications and (7) reactivates set of genes with anti -thrombotic effect; (8) triggers Treg cell differentiation leading suppressed inflammation and subsequent autoimmune processes.

[176] the mid- and long-term side effects of COVID-19 vaccines that can be ameliorated by 5-azacitidine treatment.

Example 2: Phase I/II open-label study

[177] A Phase Eli open-label study for 5-azacitidine, initiated with a lead-in dose escalation pharmacokinetic Phase I/b part in the 20-50 mg/m2 range to evaluate safety in hospitalized

COVID-19 patients in severe infection with risk of progression as add-on therapy to standard of care, continued with a randomized, controlled, open-label adaptive Phase II part to determine efficacy and safety will be conducted. Phase Eb part will be a dose escalation with multiple ascending doses (MAD) part for safety to establish the recommended Phase 2 dose (MRP2D) in range of 20-50 mg/m2 when 5-azacitidine given daily s.c. on a continuous basis for 7 days as add-on to standard of care (SOC) therapy. For an additional safety measure on kinetics of s.c. administration of 5-azacitidine as add-on to SOC, samples will be obtained for the first 3 subjects for 24 hours and additional one sample on each day 3 and day 7. Phase II part will be an open label, randomized controlled interventional adaptive design study conducted with the MRP2D established as add on therapy to SOC in Stage 2 to enroll up to 40 patients, and extended to Stage 3 with additional max. 95 subjects to enroll based on interim statistical recommendation. In the Phase 2 part the patients will be randomized in a 3:2 ratio to receive standard of care plus Azacitidine or standard of care only, respectively.

[178] Primary objectives of Phase II will be to evaluate the responder rate out of subjects enrolled and completed the treatment period at day 10 of trial by the primary endpoint in each treatment group. The state “Responder”/ “Non-Responder” to be evaluated by the composite outcome criteria as follows. Subject will be defined as “Responder” at the time point of evaluation in case one of the three outcome criteria below is fulfilled: 1) No further worsening of respiratory function as defined a) Improvement of oxygen saturation >3 percentage points or >10%, with stable Fi02 or b) with a possibility to reduce Fi02 to maintain adequate saturation with 100 points; 2) Significant reduction in number of viral replicas detected as below 5% of baseline in the case of quantitative PCR was performed; or the PCR test is turned out negative at Ctl8 sensitivity limit in case of qualitative PCR test performed at baseline; 3) Change in clinical state assessed by a 6-point ordinal scale (6-POC). Clinical Improvement since start of treatment, defined as a decrease of at least 1 point from baseline on a six-point ordinal scale. If none of the above three criteria is fulfilled, then the subject will be considered as “Non-Responder” at the time point of evaluation.

[179] Secondary Objective of Phase 2 will be

1. To evaluate the change in clinical state compared to control group - based on Clinical improvement (assessed by a 6-point ordinal scale, 6-POC) defined as a decrease of at least by 1 point from baseline on a six-point ordinal scale as described below: 1. Not hospitalized/discharged; 2. Hospitalized, not requiring supplemental oxygen; 3. Hospitalized, requiring supplemental oxygen; 4. Hospitalized, requiring nasal high-flow oxygen therapy, noninvasive mechanical ventilation, or both; 5. Hospitalized, requiring invasive mechanical ventilation, extra-corporeal membrane oxygenation (ECMO), or both; and 6. Death. 2. To assess and demonstrate the efficacy on the virological status of SARS-CoV-2 patients by virion replicates: Significant reduction in number of viral replicas detected: as below 5% of baseline in the case of quantitative PCR was performed; or the PCR test is turned out negative at Ctl8 sensitivity limit in case of qualitative PCR test performed at baseline. 3. To assess changes of Disease Severity (DiS) by the proportion of patients: a) with

ICU admission [Time Frame: within 10 days after randomization], b) requiring mechanical ventilation [Time Frame: within 14 days after randomization], c) a need for intubation [Time Frame: 14 days after randomization], d) a change in oxygenation index [Time Frame: 14 days after randomization], e) Oxygenation index is (OI) used to assess severity of hypoxic respiratory failure. (OI calculated as

= mean airway pressure (MAP) x Fraction of inspired oxygen (Fi02) x 100÷ partial pressure of oxygen (Pa02). (This will be measured daily while subject is on mechanical ventilation up to 6 weeks), f) death [Time Frame: 21/28 days after randomization], g) by the length and duration of mechanical ventilation (days) [Time Frame: Up to day 28 after randomization upon the need of mechanical ventilation]

4. To obtain information on changes in Symptoms Severity (WHO SyS): assessed by the World Health Organization (WHO) Coronavirus Disease 2019 (COVID19) ordinal 8-point scale measured daily up to 14 days after last dose of medication starting from baseline [Time Frame: 7 and 14 days from baseline]

5. To assess the risk reduction effect of study treatment on overall mortality by the 28- day survival: a) by the risk reduction effect of study treatment on Acute Respiratory Distress Syndrome (ARDS), b) to assess the risk reduction effect of study treatment by percentage of cumulative „Responders” within the treatment groups

6. Length of stay in hospital [Time Frame: Till hospital discharge, up to 28 days] measured as duration of days from baseline to hospital discharge.

7. To obtain safety information - by detection of adverse drug reaction and assess severity profile during treatment, with a special interest to renal toxicity parameters - by frequency and distribution ADR during the treatment and in the follow-up post treatment period in both arms. It will be monitored and graded using Common Terminology Criteria Adverse Events version 5.0. 8. To evaluate the ratio of “Responders”/ “Non-Responders” after day 3, 5, 10 and 14 of randomization.

9. Time (days) to clinical improvement [Time Frame: Up to 28 days or hospital discharge] Number of days for subject that have a reduction by at least 2 points from baseline on a six -point ordinal scale: (assessed by a 6-point ordinal scale, 6- POC)

10. Routine laboratory parameters assessment: total blood count, routine chemistry, IL-6, D-dimer, ferritin, CRP, pro-BNP. [Timeframe: at baseline, then on days 1, 2, 3, 5, 7, 10, 14, 21 and 28.]

11. Evaluations of CT Image scan of the chest. [Time Frame baseline, and on day 7, 14, 21 and 28.]

12. Evaluation of cytokine status by the Multicytokine panel and FACS. [Time Frame: at baseline and on day 7, 14, 21 and 28.]

[180] Study population: Hospitalized symptomatic COVID-19 patients with confirmed SARSCoV2 infection will be included with a presence of clinical signs and a potentially progressive disease, confirmed by lab results at least one positive PCR test and a medical history of a risk group or laboratory evidence indicative for risk for progression to cytokine storm or other complications.

Claims

1. A nucleoside analogue for use in treating an RNA virus involved infections and associated diseases in a human, wherein the use comprises administering therapeutically effective amount of the nucleoside analogue, wherein the nucleoside analogue is selected from the group of methylation inhibitors, - cyano substituted nucleosides, flaviviral methyltransferase and rigid amphipathic nucleosides, ribavirin and other nucleoside synthesis inhibitors and rigid amphipathic nucleosides, wherein the methylation inhibitors are 5-azacitidine, 5-aza-2'-deoxycytidine, 5-fluoro-2'- deoxycytidine, and zebularine; and wherein G-cyano substituted nucleosides are selected from G-cyano substituted C- nucleoside derived from 4-aza-7,9-dideazaadenosine, 2’-C-methyladenosine, 7-deaza-2’- C-methyl-adenosine, phosphoramidate prodrug of 6-0-methyl-2’-C-methylguanosine, T - C-methylcytidine, 2’-C-methyluridine, 2’-C-ethynyladenosine, Sofosbuvir, 7-deaza derivative of 2’-C-ethynyladenosine, 2’-ethynyl modified derivative of 7-deaza derivative of 2’-C-ethynyladenosine, isobutyryl ester prodrug of 2’-ethynyl modified derivative of 7-deaza derivative of 2’-C-ethynyladenosine, 4’-C-azidocytidine, Balapiravir, RO-9187, BCX4430, T-1106, 6-Methyl-7-deazaadenosine, N6-(9-antranylmethyl) adenosine, N6- (1-pyrenylmethyl) adenosine, N6-benzyl-5’-0-triisopropylsilyl adenosine, N6-benzyl-5’- O-trityl adenosine, N6-benzyl-5’-0-tert-butyldimethylsilyl-adenosine, 2’,5’-di-0- trityluridine, 3 5 ’-di -O-trityl uridine; and wherein the ribavirin and other nucleoside synthesis inhibitors are selected from ribavirin, l-beta-D-ribofuranosyl-3-ethynyl-[l,2,4]triazole and 6-azauridine; and wherein the rigid amphipathic nucleosides are selected from 5-(perylen-3-yl)ethynyl- arabino-uridine, 5-(perylen-3-yl)ethynyl-2’-deoxy-uridine and 5-(pyren-l-yl)ethynyl-20- deoxy-uridine.

2. The nucleoside analogue for use of Claim 1, wherein the nucleoside analogue is 5- azacitidine.

3. The nucleoside analogue for use of Claim 1, wherein said therapeutically effective amount of a nucleoside analogue is 5-75 mg/m² or 0.1-2.5 mg/kg dose.

4. The nucleoside analogue for use of Claim 1, wherein said RNA virus is a positive-sense RNA virus (+ssRNA) and selected from the group of coronaviridae, flaviviridae and togaviridae, wherein the coronaviridae are selected from the group of 29E (alpha coronavirus), NL63 (alpha coronavirus), OC43 (beta coronavirus), HKU1 (beta coronavirus), MERS-CoV (the beta coronavirus that causes Middle East Respiratory Syndrome, or MERS), SARS- CoV (the beta coronavirus that causes Severe Acute Respiratory Syndrome, or SARS) and SARS-CoV-2 (the novel coronavirus that causes coronavirus disease 2019, or COVID-19).

5. The nucleoside analogue for use of Claim 4, wherein the coronaviridae are selected from MERS-CoV (the beta coronavirus or MERS), SARS-CoV (the beta coronavirus or SARS) and SARS-CoV-2 (COVID-19).

6. The nucleoside analogue for use of Claim 1, wherein the RNA virus involved diseases are Middle East Respiratory Syndromes and Severe Acute Respiratory Syndromes.

7. The nucleoside analogue for use of Claim 1, wherein the therapeutically effective amount of the nucleoside analogue is administered as add-on therapy to standard of care.

8. The nucleoside analogue for use of Claim 1, wherein the therapeutically effective amount of the nucleoside analogue is administered subcutaneously or intravenously at 5-75 mg/m² or 0.1-2.5 mg/kg dose for 3-14 days.

9. The nucleoside analogue for use of Claim 1, wherein the RNA virus involved and associated diseases are selected from the group of upper respiratory tract viral infection showing nonspecific symptoms such as fever, fatigue, cough, anorexia, malaise, muscle pain, sore throat, dyspnea, nasal congestion, or headache; and/or have pneumonia with no signs of severe pneumonia and no need for supplemental oxygen; and/or have severe pneumonia; and/or infection related complications, such as acute respiratory distress syndrome (ARDS), acute respiratory failure, cardiovascular complications including venous and arterial thromboembolic diseases such as symptomatic acute pulmonary embolism, deep-vein thrombosis, stroke, ischemic stroke, myocardial infarction or systemic arterial embolism, acute liver injury, cytokine release syndrome including multisystem inflammatory syndrome and Kawasaki disease, septic shock, disseminated intravascular coagulation, venous thromboembolism, secondary infection, acute kidney injury, pancreatic injury, neurologic complications including hypoxic brain injury, where severe pneumonia can result in systemic hypoxia leading to brain damage and immune mediated injury that causes vascular leakage, activation of complement and coagulation cascade, dizziness, headache, acute cerebrovascular disease, impaired consciousness, transverse myelitis, acute hemorrhagic necrotizing encephalopathy, ancephalopathy ancephalitis, apilepsy, ataxia and peripheral such as hypogeusia, hyposmia, neuralgia, Guillian Barre syndrome, skeletal muscle injury, disseminated intravascular coagulation and end organ damage, rhabdomyolysis, pregnancy-related complications and secondary infections including aspergillosis, Acinetobacter baumannii , Klebsiella pneumoniae , Aspergillus flavus , Candida glabrata, Candida albicans , Enterobacter cloacae , Acinetobacter baumannii and Legionella pneumophillia.

10. A nucleoside analogue for use in the treatment of post-acute syndromes of RNA viruses involved infections and associated diseases in a human, wherein the use comprisesadministering therapeutically effective amount of the nucleoside analogue.

11. The nucleoside analogue for use of Claim 10, wherein the post-acute syndromes of RNA viruses involved infections includes highest risk for long-term pulmonary complications, including persistent diffusion impairment and radiographic pulmonary abnormalities (such as pulmonary fibrosis), thromboprophylaxis including segmental pulmonary embolism, intracardiac thrombus, thrombosed arteriovenous fistula and ischemic stroke, postural orthostatic tachycardia syndrome and inappropriate sinus tachycardia, chronic malaise, diffuse myalgia, depressive symptoms and non-restorative sleep, ischemic or hemorrhagic stroke, hypoxic-anoxic damage, posterior reversible encephalopathy syndrome and acute disseminated myelitis, myopathy and neuropathies, renal sequelae, subacute thyroiditis with clinical thyrotoxicosis, latent thyroid autoimmunity, new-onset Hashimoto’s thyroiditis or Graves’ disease, significant gastrointestinal and hepatobiliary sequelae, neurological complications, such as headache, altered mental status, encephalopathy, cranial nerve palsies, stroke, seizure, reduced reflexes, muscle weakness and Guillain Barre Syndrome.

12. The nucleoside analogue for use of Claim 10, wherein the nucleoside analogue is 5- azacitidine.

13. A nucleoside analogue for use in treating the symptoms of short- and long-term adverse events and related diseases following immunization by vaccine to prevent RNA viruses involved infections and associated diseases in a human, wherein the use comprises administering therapeutically effective amount of the nucleoside analogue.

14. The nucleoside analogue for use of Claim 13, wherein the nucleoside analogue is 5- azacitidine.