Search Results (6)

Monkeypox (Mpox), a zoonotic viral disease caused by the Monkeypox Virus (MPXV), has gained significant attention in recent years due to its increasing incidence and the grave threat it poses to global health. MPXV has spread at a rapid pace during the COVID-19 pandemic, causing 10,000+ confirmed cases and ~300 fatalities in 122 countries. This virus comprises two major clades, Clade I (Central African), which is evidently more virulent, and Clade II (West African), which has caused the recent outbreaks across the world and caused fewer deaths. Clinically, Mpox presents as a milder form with fever, lymphadenopathy, and vesiculopustular rash similar to smallpox. Diagnostic measures such as polymerase chain reaction (PCR) are the main diagnostic confirmatory tools. Advanced diagnostics involve electronic microscopy, serology, and immunohistochemistry. Alternative drugs like tecovirimat and brincidofovir have demonstrated potential for treating smallpox, but there is scanty evidence on their efficacy against MPXV. Most recent advancements in the study of vaccines have resulted in the creation and introduction of MVA-BN (JYNNEOS/Imvanex/Imvamune) and ACAM2000 vaccines, which conferred cross-protection against MPXV. MVA-BN is suggested to perform better than other types due to its enhanced safety and immunogenicity. Researchers are also developing DNA and protein subunit vaccines against Mpox to induce specific immune responses by presenting viral proteins. The discovery of novel vaccine candidates and antiviral treatments will be needed to prevent future outbreaks and reduce the global health burden of Mpox. This review focuses on the characterization of MPXV, summarizing current knowledge on its genomic structure, pathogenesis, replication, potential targets of anti-MPXV drugs, clinical features, and epidemiological patterns, along with recent advances in vaccine development. Full article

Introduction: Despite the impressive progress carried out in the field of biomedical sciences in recent decades, the incidence of emerging and neglected lethal viral infections mainly belonging to the Coronaviridae, Filoviridae, Arenaviridae, Bunyaviridae, and Paramyxoviridae families has considerably impaired human health. The worldwide vaccination campaign at the end of the 1970s determined the eradication of smallpox. However, the growing number of cases of diseases linked to orthopoxvirus diseases, such as the recent epidemic of monkeypox zoonosis in various countries around the world, has increased the need for knowledge of these viral pathogens. To date, there is no specific treatement for Monkeypox virus (MPXV) infection. However, several antiviral drugs used to treat Smallpox and other viral infections could also be beneficial for Monkeypox disease. In this study we report the design and synthesis of new, variously substituted benzimidazole derivatives and the evaluation of their cytotoxicity and antiviral activity against representatives of the Orthopoxvirus genus, Vaccinia Virus (VV), closely related to variola virus and MPXV. Methods: A combination of cell-based assays and experimental techniques was used to investigate the cytotoxicity, antiviral activity, and mechanisms of action of the most interesting compound. Results: In our study, new, variously substituted benzimidazoles showed interesting EC₅₀ values against vaccinia and MPXV and a cytotoxic profile in the high micromolar range. Conclusions: Our work shows that the new tested benzimidazole derivatives possess appealing activity and selectivity, accompanied by low cytotoxicity. These results set a valid foundation with which to identify potent and selective anti-Poxvirus agents. Full article

Viruses are minuscule infectious agents that reproduce exclusively within the living cells of an organism and are present in almost every ecosystem. Their continuous interaction with humans poses a significant threat to the survival and well-being of everyone. Apart from the common cold or seasonal influenza, viruses are also responsible for several important diseases such as polio, rabies, smallpox, and most recently COVID-19. Besides the loss of life and long-term health-related issues, clinical viral infections have significant economic and social impacts. Viral enzymes, especially proteases which are essential for viral multiplication, represent attractive drug targets. As a result, screening of viral protease inhibitors has gained a lot of interest in the development of anti-viral drugs. Despite the availability of anti-viral therapeutics, there is a clear need to develop novel curative agents that can be used against a given virus or group of related viruses. This review highlights the importance of yeasts as an in vivo model for screening viral enzyme inhibitors. We also discuss the advantages of yeast-based screening platforms over traditional assays. Therefore, in the present article, we discuss why yeast is emerging as a model of choice for in vivo screening of anti-viral molecules and why yeast-based screening will become more relevant in the future for screening anti-viral and other molecules of clinical importance. Full article

Background: Since most of the modern human population has no anti-smallpox immunity, it is extremely important to develop and implement effective drugs for the treatment of smallpox and other orthopoxvirus infections. The objective of this study is to determine the main characteristics of the chemical substance NIOCH-14 and its safety and bioavailability in the body of laboratory animals. Methods: The safety of NIOCH-14 upon single- or multiple-dose intragastric administration was assessed according to its effect on the main hematological and pathomorphological parameters of laboratory mice and rats. In order to evaluate the pharmacokinetic parameters of NIOCH-14 administered orally, a concentration of ST-246, the active metabolite of NIOCH-14, in mouse blood and organs was determined by tandem mass spectrometry and liquid chromatography. Results: The intragastric administration of NIOCH-14 at a dose of 5 g/kg body weight caused neither death nor signs of intoxication in mice. The intragastric administration of NIOCH-14 to mice and rats at doses of 50 and 150 µg/g body weight either as a single dose or once daily during 30 days did not cause animal death or critical changes in hematological parameters and the microstructure of internal organs. The tissue availability of NIOCH-14 administered orally to the mice at a dose of 50 µg/g body weight, which was calculated according to concentrations of its active metabolite ST-246 for the lungs, liver, kidney, brain, and spleen, was 100, 69.6, 63.3, 26.8 and 20.3%, respectively. The absolute bioavailability of the NIOCH-14 administered orally to mice at a dose of 50 µg/g body weight was 22.8%. Conclusion: Along with the previously determined efficacy against orthopoxviruses, including the smallpox virus, the substance NIOCH-14 was shown to be safe and bioavailable in laboratory animal experiments. Full article

Monkeypox disease (MPX) is currently considered a global threat after COVID-19. European Medicines Agency (EMA) approved Tecovirimat in capsule dosage form (200 mg) as the first treatment for MPX in January 2022. This article highlights Tecovirimat’s development and patent literature review and is believed to benefit the scientists working on developing MPX treatments. The literature for Tecovirimat was gathered from the website of SIGA Technologies (developer of Tecovirimat), regulatory agencies (EMA, United States Food and Drug Administration (USFDA), and Health Canada), PubMed, and freely accessible clinical/patent databases. Tecovirimat was first recognized as an anti-orthopoxvirus molecule in 2002 and developed by SIGA Technologies. The USFDA and Health Canada have also recently approved Tecovirimat to treat smallpox in 2018 and 2021, respectively. The efficacy of Tecovirimat was verified in infected non-human primates (monkeys) and rabbits under the USFDA’s Animal Rule. Most clinical studies have been done on Tecovirimat’s safety and pharmacokinetic parameters. The patent literature has revealed inventions related to the capsule, injection, suspension, crystalline forms, amorphous form, and drug combinations (Tecovirimat + cidofovir) and process for preparing Tecovirimat. The authors foresee the off-label use of Tecovirimat in the USA and Canada for MPX and other orthopoxvirus infections. The authors also trust that there is immense scope for developing new Tecovirimat-based treatments (new drug combinations with other antivirals) for orthopoxvirus and other viral diseases. Drug interaction studies and drug resistance studies on Tecovirimat are also recommended. Tecovirimat is believed to handle the current MPX outbreak and is a new hope of biosecurity against smallpox or orthopoxvirus-related bioterrorism attack. Full article

Despite the eradication of smallpox four decades ago, poxviruses continue to be a threat to humans and animals. The arsenal of anti-poxvirus agents is very limited and understanding mechanisms of resistance to agents targeting viral DNA polymerases is fundamental for the development of antiviral therapies. We describe here the phenotypic and genotypic characterization of poxvirus DNA polymerase mutants isolated under selective pressure with different acyclic nucleoside phosphonates, including HPMPC (cidofovir), cHPMPC, HPMPA, cHPMPA, HPMPDAP, HPMPO-DAPy, and PMEO-DAPy, and the pyrophosphate analogue phosphonoacetic acid. Vaccinia virus (VACV) and cowpox virus drug-resistant viral clones emerging under drug pressure were characterized phenotypically (drug-susceptibility profile) and genotypically (DNA polymerase sequencing). Different amino acid changes in the polymerase domain and in the 3′-5′ exonuclease domain were linked to drug resistance. Changes in the 3′-5′ domain emerged earlier than in the polymerase domain when viruses acquired a combination of mutations. Our study highlights the importance of poxvirus DNA polymerase residues 314, 613, 684, 688, and 851, previously linked to drug resistance, and identified several novel mutations in the 3′-5′ exonuclease domain (M313I, F354L, D480Y) and in the DNA polymerase domain (A632T, T831I, E856K, L924F) associated with different drug-susceptibility profiles. Furthermore, a combination of mutations resulted in complex patterns of cross-resistance. Modeling of the VACV DNA polymerase bearing the newly described mutations was performed to understand the effects of these mutations on the structure of the viral enzyme. We demonstrated the emergence of drug-resistant DNA polymerase mutations in complex patterns to be considered in case such mutations should eventually arise in the clinic. Full article