Cidofovir Activity against Poxvirus Infections

Mpox Virus and its ocular surface manifestations

The Mpox virus (MPXV) is the causative agent of human Mpox disease - a debilitating rash illness similar to smallpox. Although Clade I MPXV has remained endemic to West and Central Africa, Clade II MPXV has been responsible for many outbreaks worldwide. The most recent outbreak in 2022 resulted from the rapid spread of a new clade of MPXV, classified into Clade IIb - a distinct lineage from the previously circulating viral strains. The rapid spread and increased severity of Mpox disease by the Clade IIb strain have raised the serious public health imperative of better understanding the host and viral determinants during MPXV infection. In addition to typical skin rashes, including in the periorbital area, MPXV causes moderate to severe ophthalmic manifestations - most commonly, ocular surface complications (e.g., keratitis, conjunctivitis, blepharitis). While ocular manifestations of Clade I Mpox within the Congo basin have been well-reported, global incidence trends of ocular Mpox cases by Clade IIb are still emerging. Given the demonstrated ability of all MPXV strains to auto-inoculate ocular tissue, alongside the enhanced transmissibility of the Clade IIb virus, there is an urgent need to elucidate the mechanisms by which MPXV causes ocular anomalies. In this review, we discuss the viral and genomic structures of MPXV, the epidemiology, and pathology of systemic and ocular Mpox, as well as potential prophylactic and therapeutic interventions.

Machine learning and classical MD simulation to identify inhibitors against the P37 envelope protein of monkeypox virus

Monkeypox virus (MPXV) outbreak is a serious public health concern that requires international attention. P37 of MPXV plays a pivotal role in DNA replication and acts as one of the promising targets for antiviral drug design. In this study, we intent to screen potential analogs of existing FDA approved drugs of MPXV against P37 using state-of-the-art machine learning and computational biophysical techniques. AlphaFold2 guided all-atoms molecular dynamics simulations optimized P37 structure is used for molecular docking and binding free energy calculations. Similar to members of Phospholipase-D family , the predicted P37 structure also adopts a β-α-β-α-β sandwich fold, harbouring strongly conserved HxKxxxxD motif. The binding pocket comprises of Tyr48, Lys86, His115, Lys117, Ser130, Asn132, Trp280, Asn240, His325, Lys327 and Tyr346 forming strong hydrogen bonds and dense hydrophobic contacts with the screened analogs and is surrounded by positively charged patches. Loops connecting the two domains and C-terminal region exhibit high degree of flexibility. In some structural ensembles, the partial disorderness in the C-terminal region is presumed to be due to its low confidence score, acquired during structure prediction. Transition from loop to β-strands (244-254 aa) in P37-Cidofovir and its analog complexes advocates the need for further investigations. MD simulations support the accuracy of the molecular docking results, indicating the potential of analogs as potent binders of P37. Taken together, our results provide preferable understanding of molecular recognition and dynamics of ligand-bound states of P37, offering opportunities for development of new antivirals against MPXV. However, the need of in vitro and in vivo assays for confirmation of these results still persists.Communicated by Ramaswamy H. Sarma.

Potential use of cidofovir, brincidofovir, and tecovirimat drugs in fighting monkeypox infection: recent trends and advancements

Recent years have witnessed the rise of more recent pandemic outbreaks including COVID-19 and monkeypox. A multinational monkeypox outbreak creates a complex situation that necessitates countermeasures to the existing quo. The first incidence of monkeypox was documented in the 1970s, and further outbreaks led to a public health emergency of international concern. Yet as of right now, neither vaccines nor medicines are certain to treat monkeypox. Even the inability of conducting human clinical trials has prevented thousands of patients from receiving effective disease management. The current state of the disease's understanding, the treatment options available, financial resources, and lastly international policies to control an epidemic state are the major obstacles to controlling epidemics. The current review focuses on the epidemiology of monkeypox, scientific ideas, and available treatments, including potential monkeypox therapeutic methods. As a result, a thorough understanding of monkeypox literature will facilitate in the development of new therapeutic medications for the prevention and treatment of monkeypox.

Monkeypox: An outbreak of a rare viral disease

Monkeypox is a viral zoonotic disease rarely found outside Africa. Monkeypox can be spread from person to person through close contact with an infected person, and the rate of transmission is not very high. In addition, monkeypox and variola virus are both pox viruses, and the spread of monkeypox virus was also controlled to some extent by the smallpox campaign, so monkeypox was not widely paid attention to. However, as smallpox vaccination is phased out in various countries or regions, people's resistance to orthopoxviruses is decreasing, especially among people who have not been vaccinated against smallpox. This has led to a significant increase in the frequency and geographical distribution of human monkeypox cases in recent years, and the monkeypox virus has become the orthopoxvirus that poses the greatest threat to public health. Since the last large-scale monkeypox infection was detected in 2022, the number of countries or territories affected has exceeded 100. Many confirmed and suspected cases of monkeypox have been found in individuals who have not travelled to affected areas, and the route of infection is not obvious, making this outbreak of monkeypox a cause for concern globally. The purpose of this systematic review is to further understand the pathophysiological and epidemiological characteristics of monkeypox, as well as existing prevention and treatment methods, with a view to providing evidence for the control of monkeypox.

Molecular Virology of Orthopoxviruses with Special Reference to Monkeypox Virus

Poxviruses are large (200-450 nm) and enveloped viruses carrying double-stranded DNA genome with an epidermal cell-specific adaptation. The genus Orthopoxvirus within Poxviridae family constitutes several medically and veterinary important viruses including variola (smallpox), vaccinia, monkeypox virus (MPXV), and cowpox. The monkeypox disease (mpox) has recently emerged as a public health emergency caused by MPXV. An increasing number of human cases of MPXV have been documented in non-endemic nations without any known history of contact with animals brought in from endemic and enzootic regions, nor have they involved travel to an area where the virus was typically prevalent. Here, we review the MPXV replication, virus pathobiology, mechanism of viral infection transmission, virus evasion the host innate immunity and antiviral therapies against Mpox. Moreover, preventive measures including vaccination were discussed and concluded that cross-protection against MPXV may be possible using antibodies that are directed against an Orthopoxvirus. Despite the lack of a specialised antiviral medication, several compounds such as Cidofovir and Ribavirin warrant consideration against mpox.

The Overview of Potential Antiviral Bioactive Compounds in Poxviruses

Poxviruses belong to the family of double-stranded DNA viruses, and it is pathogenic for humans and spread worldwide. These viruses cause infections and various diseases in human. So, it is required to develop new drugs for the treatment of smallpox or other poxvirus infections. Very few potential compounds for the treatment of poxvirus such as smallpox, chickenpox, and monkeypox have been reported. Most of the compounds has used as vaccines. Cidofovir is most commonly used as a vaccine for the treatment of poxviruses. There are no phytochemicals reported for the treatment of poxviruses. Very few phytochemicals are under investigation for the treatment of poxviruses.

Biological Characteristics and Pathogenesis of Monkeypox Virus: An Overview

Although the smallpox virus has been eradicated worldwide, the World Health Organization (WHO) has issued a warning about the virus's potential to propagate globally. The WHO labeled monkeypox a world public health emergency in July 2022, requiring urgent prevention and treatment. The monkeypox virus is a part of the Poxviridae family, Orthopoxvirus genus, and is accountable for smallpox, which has killed over a million people in the past. Natural hosts of the virus include squirrels, Gambian rodents, chimpanzees, and other monkeys. The monkeypox virus has transmitted to humans through primary vectors (various animal species) and secondary vectors, including direct touch with lesions, breathing particles from body fluids, and infected bedding. The viral particles are ovoid or brick-shaped, 200-250 nm in diameter, contain a single double-stranded DNA molecule, and reproduce only in the cytoplasm of infected cells. Monkeypox causes fever, cold, muscle pains, headache, fatigue, and backache. The phylogenetic investigation distinguished between two genetic clades of monkeypox: the more pathogenic Congo Basin clade and the West Africa clade. In recent years, the geographical spread of the human monkeypox virus has accelerated despite a paucity of information regarding the disease's emergence, ecology, and epidemiology. Using lesion samples and polymerase chain reaction (PCR), the monkeypox virus was diagnosed. In the USA, the improved Ankara vaccine can now be used to protect people who are at a higher risk of getting monkeypox. Antivirals that we have now work well against smallpox and may stop the spread of monkeypox, but there is no particular therapy for monkeypox.

Treatment and Vaccination for Smallpox and Monkeypox

The smallpox infection with the variola virus was one of the most fatal disorders until a global eradication was initiated in the twentieth century. The last cases were reported in Somalia 1977 and as a laboratory infection in the UK 1978; in 1980, the World Health Organization (WHO) declared smallpox for extinct. The smallpox virus with its very high transmissibility and mortality is still a major biothreat, because the vaccination against smallpox was stopped globally in the 1980s. For this reason, new antivirals (cidofovir, brincidofovir, and tecovirimat) and new vaccines (ACAM2000, LC16m8 and Modified Vaccine Ankara MVA) were developed. For passive immunization, vaccinia immune globulin intravenous (VIGIV) is available. Due to the relationships between orthopox viruses such as vaccinia, variola, mpox (monkeypox), cowpox, and horsepox, the vaccines (LC16m8 and MVA) and antivirals (brincidofovir and tecovirimat) could also be used in the mpox outbreak with positive preliminary data. As mutations can result in drug resistance against cidofovir or tecovirimat, there is need for further research. Further antivirals (NIOCH-14 and ST-357) and vaccines (VACΔ6 and TNX-801) are being developed in Russia and the USA. In conclusion, further research for treatment and prevention of orthopox infections is needed and is already in progress. After a brief introduction, this chapter presents the smallpox and mpox disease and thereafter full overviews on antiviral treatment and vaccination including the passive immunization with vaccinia immunoglobulins.

Poxviruses in Children

The family Poxviridae is a large family of viruses with a ubiquitous distribution, subdivided into two subfamilies: Chordopoxvirinae (poxviruses of vertebrates) and Entomopoxvirinae (poxviruses of insects). Only three species from the first subfamily, Orthopoxvirus (OPV), Molluscipoxvirus and Parapoxvirus, can infect the human being. In the paediatric population, viruses belonging to the first two subfamilies have the greatest importance. Following the eradication of smallpox in 1980, vaccination of the general population was discontinued after careful consideration of the risks and benefits. However, nearly all children and most of the world's population had little to no protection against OPV. The aim of this chapter is to review the current evidence on the aetiology, clinical manifestations, diagnosis and management of Poxviridae infections in children.

Mpox (formerly monkeypox): pathogenesis, prevention, and treatment

In 2022, a global outbreak of Mpox (formerly monkeypox) occurred in various countries across Europe and America and rapidly spread to more than 100 countries and regions. The World Health Organization declared the outbreak to be a public health emergency of international concern due to the rapid spread of the Mpox virus. Consequently, nations intensified their efforts to explore treatment strategies aimed at combating the infection and its dissemination. Nevertheless, the available therapeutic options for Mpox virus infection remain limited. So far, only a few numbers of antiviral compounds have been approved by regulatory authorities. Given the high mutability of the Mpox virus, certain mutant strains have shown resistance to existing pharmaceutical interventions. This highlights the urgent need to develop novel antiviral drugs that can combat both drug resistance and the potential threat of bioterrorism. Currently, there is a lack of comprehensive literature on the pathophysiology and treatment of Mpox. To address this issue, we conducted a review covering the physiological and pathological processes of Mpox infection, summarizing the latest progress of anti-Mpox drugs. Our analysis encompasses approved drugs currently employed in clinical settings, as well as newly identified small-molecule compounds and antibody drugs displaying potential antiviral efficacy against Mpox. Furthermore, we have gained valuable insights from the process of Mpox drug development, including strategies for repurposing drugs, the discovery of drug targets driven by artificial intelligence, and preclinical drug development. The purpose of this review is to provide readers with a comprehensive overview of the current knowledge on Mpox.

Comprehensive overview of 2022 human monkeypox outbreak and its pathology, prevention, and treatment: A strategy for disease control

The 2022 Monkeypox virus, an evolved DNA strain originating in Africa, exhibits heightened human-to-human transmissibility and potential animal transmission. Its host remains unidentified. While its initial slow transmission rate restrained global impact, 2022 saw a surge in cases, causing widespread concern in over 103 countries by September. This virus's distinctive human-to-human transmission marks a crucial shift, demanding a prompt revaluation of containment strategies. However, the host source for this shift requires urgent research attention. Regrettably, no universal preventive or curative methods have emerged for this evolved virus. Repurposed from smallpox vaccines, only some vaccinations offer a partial defense. Solely one therapeutic drug is available. The article's essence is to provide a comprehensive grasp of the virus's epidemiology, morphology, immune invasion mechanisms, and existing preventive and treatment measures. This knowledge equips researchers to devise strategies against its spread and potential public health implications.

Mpox and HIV-Collision of Two Diseases

PURPOSE OF REVIEW

The global outbreak of mpox has brought renewed attention to a previously neglected disease which is particularly severe in people with underlying untreated HIV co-infection. For this population, the disease is progressive, severe, and often lethal. In this review, we examine the pathogenesis of mpox disease and its collision with co-existent HIV infection and discuss key considerations for management as well as emerging clinical dilemmas and areas for future research.

RECENT FINDINGS

Co-existent untreated HIV infection characterized by severe immunocompromise potentiates the nefarious effects of monkeypox virus infection leading to severe manifestations of mpox. Treating mpox in the context of HIV requires mpox-directed therapies, supportive care, and HIV-specific treatment to restore immune function. Preventative measures for PWH are like those in healthy individuals, but the effectiveness and durability of protection conferred by existing vaccines in PWH remain to be fully characterized. Mpox is an important opportunistic infection in PWH. Clinicians should be aware of the unique features of the disease in this population and approaches to care and management of mpox in PWH.

Addressing the resurgence of global monkeypox (Mpox) through advanced drug delivery platforms

Monkeypox (Mpox) is a transmissible infection induced by the Monkeypox virus (a double-stranded DNA virus), recognised under the family orthopoxvirus genus. Monkeypox, like endemic diseases, is a substantial concern worldwide; thus, comprehending the pathogenesis and mutagenesis of amino acids is indispensable to combat the infection. According to the World Health Organization's report, about 89 thousand cases with 160 mortalities have been reported from 114 countries worldwide. The conventional orthopoxvirus vaccines developed on live attenuated viruses exempted any clinical validation from combating monkeypox due to inadequate immunogenicity, toxicity, instability, and multiple doses. Therefore, novel drug delivery systems come into the conception with high biological and mechanical characteristics to address the resurgence of Global Monkeypox. The edges of metallic biomaterials, novel molecules, and vaccine development in targeted therapy increase the modulation of the immune response and blockage of host-virus interaction, with enhanced stability for the antigens. Thus, this review strives to comprehend the viral cell pathogenesis concerning amino acid mutagenesis and current epidemiological standards of the Monkeypox disease across the globe. Furthermore, the review also recapitulates the various clinical challenges, current therapies, and progressive nanomedicine utilisation in the Monkeypox outbreak reinforced by various clinical trial reports. The contemporary challenges of novel drug delivery systems in Monkeypox treatment cannot be overlooked, and thus, authors have outlined the future strategies to develop successful nanomedicine to combat monkeypox. Future pandemics are inevitable but can be satisfactorily handled if we comprehend the crises, innovate, and develop cutting-edge technologies, especially by delving into frontiers like nanotechnology.

Brincidofovir: A Novel Agent for the Treatment of Smallpox

OBJECTIVE

This article reviews the published data encompassing the development, pharmacology, efficacy, and safety of brincidofovir, a nucleotide analogue DNA polymerase inhibitor developed for the treatment of smallpox.

DATA SOURCES

A literature review was conducted in PubMed, MEDLINE, and Clinicaltrials.gov from inception up to December 2022, using terms Tembexa, brincidofovir, CMX001, smallpox treatment, and variola treatment.

STUDY SELECTION AND DATA EXTRACTION

Data were limited to studies published in English language, which evaluated the efficacy and safety of brincidofovir.

DATA SYNTHESIS

Two surrogate animal models were included in the Food and Drug Administration's (FDA) decision to approve brincidofovir: ectromelia virus in mice and rabbitpox in rabbits. Phases 2 and 3 studies established safety for approval. Brincidofovir biweekly for the treatment of disseminated adenovirus disease resulted in all-cause mortality, ranging from 13.8% to 29%. In a study for cytomegalovirus prophylaxis, patients with clinically significant cytomegalovirus infection through week 24 posttransplant was 51.2% with brincidofovir and 52.3% with placebo.

CONCLUSIONS

Brincidofovir adds a second oral agent to treat smallpox, with a different mechanism of action than tecovirimat. In the event of a smallpox outbreak, prompt treatment will be necessary to contain its spread. Brincidofovir shows efficacy in surrogate animal models. In healthy volunteers and individuals treated, or used as prophylaxis, for cytomegalovirus or adenovirus, the primary adverse events were gastrointestinal in addition to transient hepatotoxicity. Additionally, excessive deaths were observed in hematopoietic cell transplant patients receiving it as cytomegalovirus prophylaxis, requiring a black box warning.

Identification of In Vitro Inhibitors of Monkeypox Replication

Monkeypox virus (MPXV) infections in humans have historically been restricted to regions of endemicity in Africa. However, in 2022, an alarming number of MPXV cases were reported globally, with evidence of person-to-person transmission. Because of this, the World Health Organization (WHO) declared the MPXV outbreak a public health emergency of international concern. The supply of MPXV vaccines is limited, and only two antivirals, tecovirimat and brincidofovir, approved by the U.S. Food and Drug Administration (FDA) for the treatment of smallpox, are currently available for the treatment of MPXV infection. Here, we evaluated 19 compounds previously shown to inhibit different RNA viruses for their ability to inhibit orthopoxvirus infections. We first used recombinant vaccinia virus (rVACV) expressing fluorescence (mScarlet or green fluorescent protein [GFP]) and luciferase (Nluc) reporter genes to identify compounds with antiorthopoxvirus activity. Seven compounds from the ReFRAME library (antimycin A, mycophenolic acid, AVN-944, pyrazofurin, mycophenolate mofetil, azaribine, and brequinar) and six compounds from the NPC library (buparvaquone, valinomycin, narasin, monensin, rotenone, and mubritinib) showed inhibitory activity against rVACV. Notably, the anti-VACV activity of some of the compounds in the ReFRAME library (antimycin A, mycophenolic acid, AVN-944, mycophenolate mofetil, and brequinar) and all the compounds from the NPC library (buparvaquone, valinomycin, narasin, monensin, rotenone, and mubritinib) were confirmed with MPXV, demonstrating their inhibitory activity in vitro against two orthopoxviruses. IMPORTANCE Despite the eradication of smallpox, some orthopoxviruses remain important human pathogens, as exemplified by the recent 2022 monkeypox virus (MPXV) outbreak. Although smallpox vaccines are effective against MPXV, access to those vaccines is limited. In addition, current antiviral treatment against MPXV infections is limited to the use of the FDA-approved drugs tecovirimat and brincidofovir. Thus, there is an urgent need to identify novel antivirals for the treatment of MPXV infection and other potentially zoonotic orthopoxvirus infections. Here, we show that 13 compounds, derived from two different libraries, previously found to inhibit several RNA viruses, also inhibit VACV. Notably, 11 compounds also displayed inhibitory activity against MPXV.

Identification of IMP Dehydrogenase as a Potential Target for Anti-Mpox Virus Agents

Mpox virus (formerly monkeypox virus [MPXV]) is a neglected zoonotic pathogen that caused a worldwide outbreak in May 2022. Given the lack of an established therapy, the development of an anti-MPXV strategy is of vital importance. To identify drug targets for the development of anti-MPXV agents, we screened a chemical library using an MPXV infection cell assay and found that gemcitabine, trifluridine, and mycophenolic acid (MPA) inhibited MPXV propagation. These compounds showed broad-spectrum anti-orthopoxvirus activities and presented lower 90% inhibitory concentrations (0.026 to 0.89 μM) than brincidofovir, an approved anti-smallpox agent. These three compounds have been suggested to target the postentry step to reduce the intracellular production of virions. Knockdown of IMP dehydrogenase (IMPDH), the rate-limiting enzyme of guanosine biosynthesis and a target of MPA, dramatically reduced MPXV DNA production. Moreover, supplementation with guanosine recovered the anti-MPXV effect of MPA, suggesting that IMPDH and its guanosine biosynthetic pathway regulate MPXV replication. By targeting IMPDH, we identified a series of compounds with stronger anti-MPXV activity than MPA. This evidence shows that IMPDH is a potential target for the development of anti-MPXV agents. IMPORTANCE Mpox is a zoonotic disease caused by infection with the mpox virus, and a worldwide outbreak occurred in May 2022. The smallpox vaccine has recently been approved for clinical use against mpox in the United States. Although brincidofovir and tecovirimat are drugs approved for the treatment of smallpox by the U.S. Food and Drug Administration, their efficacy against mpox has not been established. Moreover, these drugs may present negative side effects. Therefore, new anti-mpox virus agents are needed. This study revealed that gemcitabine, trifluridine, and mycophenolic acid inhibited mpox virus propagation and exhibited broad-spectrum anti-orthopoxvirus activities. We also suggested IMP dehydrogenase as a potential target for the development of anti-mpox virus agents. By targeting this molecule, we identified a series of compounds with stronger anti-mpox virus activity than mycophenolic acid.

A systematic review to identify novel clinical characteristics of monkeypox virus infection and therapeutic and preventive strategies to combat the virus

Since May 2022, there has been a global increase in the number of Mpox virus (MPXV) cases in countries that were previously considered non-endemic. In July 2022, the World Health Organization (WHO) declared this outbreak a public health emergency of international concern. The objective of this systematic review is to examine the novel clinical features of Mpox and to assess the available treatment options for managing the disease in patients who are afflicted with it. We conducted a systematic search in several databases, including PubMed, Google Scholar, Cochrane Library, and the grey literature, from May 2022 to February 2023. We identified 21 eligible studies, which included 18,275 Mpox cases, for final qualitative analysis. The majority of cases were reported in men who have sex with men (MSM) and immunocompromised individuals with HIV (36.1%). The median incubation period was 7 days (IQR: 3-21). The novel clinical manifestations include severe skin lesions on the palms, oral and anogenital regions, as well as proctitis, penile edema, tonsillitis, ocular disease, myalgia, lethargy, and sore throat, without any preceding prodromal symptoms or systemic illness. In addition, fully asymptomatic cases were documented, and various complications, including encephalomyelitis and angina, were noted. Clinicians must be familiar with these novel clinical characteristics, as they can aid in testing and tracing such patients, as well as asymptomatic high-risk populations such as heterosexuals and MSM. In addition to supportive care, currently, there are several effective prophylactic and treatment strategies available to combat Mpox, including the vaccines ACAM2000 and MVA-BN7, as well as the immunoglobulin VIGIV and the antivirals tecovirimat, brincidofovir, and cidofovir against severe Mpox infection.

Monkeypox: A New Challenge for Global Health System?

The COVID-19 pandemic, starting in 2020, has presented a major challenge in terms of early diagnosis and the subsequent containment and management of severe cases. The spread of viruses such as monkeypox in non-endemic countries is now creating new difficulties for healthcare professionals. Proper case definition and clinical examination are crucial for the early identification of suspected cases. For this reason, we performed a review of the literature in order to report the first signs, which are useful for healthcare providers for early case identification. Since 2022 to date, 86,930 laboratory-confirmed cases and 1051 probable cases have been reported worldwide, and of these, 116 were fatal cases and, for the first time, most of the cases were registered in countries that have not historically reported monkeypox and that lack direct or immediate epidemiological links to areas of West or Central Africa where the disease is endemic. Patients with Monkeypox experience prodromal symptoms, such as fever, fatigue, headache, muscle aches, and a rash after an incubation period of 5-21 days. The disease is usually self-limiting within 2-4 weeks but can lead to complications, such as pneumonia, encephalitis, kidney injury, and myocarditis in children, pregnant individuals, and those with weakened immune systems. The case-fatality ratio is between 1 and 10%. Today, prevention campaigns and the control of human monkeypox are the best weapons to prevent infection and stop transmission. Prevention strategies, such as avoiding contact with sick or dead animals, and the proper preparation of all foods containing animal meat or parts, should be adopted. Furthermore, close contact with infected people or contaminated materials should be avoided to prevent human-to-human transmission.

Computational studies on searching potential phytochemicals against DNA polymerase activity of the monkeypox virus

Objectives

The outbreak of monkeypox virus (MPXV) is an emerging epidemic of medical concern with 65353 confirmed cases of infection and a fatality of 115 worldwide. Since May 2022, MPXV has been rapidly disseminating across the globe through various modes of transmission, including direct contact, respiratory droplets, and consensual sex. Because of the limited medical countermeasures available to treat MPXV, the present study aimed to identify potential phytochemicals (limonoids, triterpenoids, and polyphenols) as antagonists to target the DNA polymerase protein of MPXV with the ultimate goal to inhibit the viral DNA replication mechanism and immune-mediated responses.

Methods

The protein-DNA and protein-ligand molecular docking were performed with the help of computational programs AutoDock Vina, iGEMDOCK and HDOCK server. The BIOVIA Discovery studio and ChimeraX were used to evaluate the protein-ligand interactions. The GROMACS 2021 was used for the molecular dynamics simulations. The ADME and toxicity properties were computed by using online servers SwissADME and pKCSM.

Results

Molecular docking of 609 phytochemicals and molecular dynamics simulations of lead phytochemicals glycyrrhizinic acid and apigenin-7-O-glucuronide generated useful data that supported the ability of phytochemicals to obstruct the DNA polymerase activity of the monkeypox virus.

Conclusions

The computational results supported that appropriate phytochemicals can be used to formulate an adjuvant therapy for the monkeypox virus.

Ophthalmic manifestations of monkeypox infection

After the global COVID-19 pandemic, there has been an alarming concern with the monkeypox (mpox) outbreak, which has affected more than 110 countries worldwide. Monkeypox virus is a doublestranded DNA virus of the genus Orthopox of the Poxviridae family, which causes this zoonotic disease. Recently, the mpox outbreak was declared by the World Health Organization (WHO) as a public health emergency of international concern (PHEIC). Monkeypox patients can present with ophthalmic manifestation and ophthalmologists have a role to play in managing this rare entity. Apart from causing systemic involvement such as skin lesions, respiratory infection and involvement of body fluids, Monkeypox related ophthalmic disease (MPXROD) causes varied ocular manifestations such as lid and adnexal involvement, periorbital and lid lesion, periorbital rash, conjunctivitis, blepharocounctivitis and keratitis. A detailed literature review shows few reports on MPXROD infections with limited overview on management strategies. The current review article is aimed to provide the ophthalmologist with an overview of the disease with a spotlight on ophthalmic features. We briefly discuss the morphology of the MPX, various modes of transmission, an infectious pathway of the virus, and the host immune response. A brief overview of the systemic manifestations and complications has also been elucidated. We especially highlight the detailed ophthalmic manifestations of mpox, their management, and prevention of vision threatening sequelae.

Human Orf with Immune-Mediated Reactions: A Systematic Review

Background: Orf is a highly contagious zoonosis caused by Orf virus (ORFV), which is endemic in sheep and goats worldwide. Human Orf is usually a self-limiting disease, but potential complications, including immune-mediated reactions, may occur. Methods: We included all articles regarding Orf-associated immunological complications published in peer-reviewed medical journals. We conducted a literature search of the United States National Library of Medicine, PubMed, MEDLINE, PubMed Central, PMC, and the Cochrane Controlled Trials. Results: A total of 16 articles and 44 patients were included, prevalently Caucasian (22, 95.7%) and female (22, 57.9%). The prevailing immunological reaction was erythema multiforme (26, 59.1%), followed by bullous pemphigoid (7, 15.9%). In most cases, the diagnosis was made on the basis of clinical and epidemiological history (29, 65.9%), while a biopsy of secondary lesions was performed in 15 patients (34.1%). A total of 12 (27.3%) patients received a local or systemic treatment for primary lesions. Surgical removal of primary lesion was described in two cases (4.5%). Orf-immune-mediated reactions were treated in 22 cases (50.0%), mostly with topical corticosteroids (12, 70.6%). Clinical improvement was reported for all cases. Conclusions: Orf-related immune reactions can have a varied clinical presentation, and it is important for clinicians to be aware of this in order to make a prompt diagnosis. The main highlight of our work is the presentation of complicated Orf from an infectious diseases specialist's point of view. A better understanding of the disease and its complications is essential to achieve the correct management of cases.

Antivirals against monkeypox infections

Monkeypox virus (MPXV) infection in humans are historically restricted to endemic regions in Africa. However, in 2022, an alarming number of MPXV cases have been reported globally with evidence of person-to-person transmission. Because of this, the World Health Organization (WHO) declared the MPXV outbreak a public health emergency of international concern. MPXV vaccines are limited and only two antivirals, tecovirimat and brincidofovir, approved by the United States (US) Food and Drug Administration (FDA) for the treatment of smallpox, are currently available for the treatment of MPXV infection. Here, we evaluated 19 compounds previously shown to inhibit different RNA viruses for their ability to inhibit Orthopoxvirus infections. We first used recombinant vaccinia virus (rVACV) expressing fluorescence (Scarlet or GFP) and luciferase (Nluc) reporter genes to identify compounds with anti-Orthopoxvirus activity. Seven compounds from the ReFRAME library (antimycin A, mycophenolic acid, AVN- 944, pyrazofurin, mycophenolate mofetil, azaribine, and brequinar) and six compounds from the NPC library (buparvaquone, valinomycin, narasin, monensin, rotenone, and mubritinib) showed antiviral activity against rVACV. Notably, the anti-VACV activity of some of the compounds in the ReFRAME library (antimycin A, mycophenolic acid, AVN- 944, mycophenolate mofetil, and brequinar) and all the compounds from the NPC library (buparvaquone, valinomycin, narasin, monensin, rotenone, and mubritinib) were confirmed with MPXV, demonstrating the broad-spectrum antiviral activity against Orthopoxviruses and their potential to be used for the antiviral treatment of MPXV, or other Orthopoxvirus, infections.

IMPORTANCE

Despite the eradication of smallpox, some Orthopoxviruses remain important human pathogens, as exemplified by the recent 2022 monkeypox virus (MPXV) outbreak. Although smallpox vaccines are effective against MPXV, there is presently limited access to those vaccines. In addition, current antiviral treatment against MPXV infections is limited to the use of the FDA-approved drugs tecovirimat and brincidofovir. Thus, there is an urgent need to identify novel antivirals for the treatment of MPXV, and other potentially zoonotic Orthopoxvirus infections. Here, we show that thirteen compounds, derived from two different libraries, previously found to inhibit several RNA viruses, exhibit also antiviral activity against VACV. Notably, eleven compounds also displayed antiviral activity against MPXV, demonstrating their potential to be incorporated into the therapeutic armamentarium to combat Orthopoxvirus infections.

An Overview of Antivirals against Monkeypox Virus and Other Orthopoxviruses

The current monkeypox outbreaks during the COVID-19 pandemic have reignited interest in orthopoxvirus antivirals. Monkeypox belongs to the Orthopoxvirus genus of the Poxviridae family, which also includes the variola virus, vaccinia virus, and cowpox virus. Two orally bioavailable drugs, tecovirimat and brincidofovir, have been approved for treating smallpox infections. Given their human safety profiles and in vivo antiviral efficacy in animal models, both drugs have also been recommended to treat monkeypox infection. To facilitate the development of additional orthopoxvirus antivirals, we summarize the antiviral activity, mechanism of action, and mechanism of resistance of orthopoxvirus antivirals. This perspective covers both direct-acting and host-targeting antivirals with an emphasis on drug candidates showing in vivo antiviral efficacy in animal models. We hope to speed the orthopoxvirus antiviral drug discovery by providing medicinal chemists with insights into prioritizing proper drug targets and hits for further development.

Therapeutics for treating mpox in humans

BACKGROUND

Mpox was declared a Public Health Emergency of International Concern (PHEIC) by the World Health Organization (WHO) on 23 July 2022, following the identification of thousands of cases in several non-endemic countries in previous months. There are currently no licenced therapeutics for treating mpox; however, some medications may be authorized for use in an outbreak. The efficacy and safety of possible therapeutic options has not been studied in humans with mpox. There is a need to investigate the evidence on safety and effectiveness of treatments for mpox in humans; should any therapeutic option be efficacious and safe, it may be approved for use around the world.

OBJECTIVES

There are two parts to this Cochrane Review: a review of evidence from randomized controlled trials (RCTs), and a narrative review of safety data from non-randomized studies. Randomized controlled trials review To systematically review the existing evidence on the effectiveness of therapeutics for mpox infection in humans compared to: a) another different therapeutic for mpox, or b) placebo, or c) supportive care, defined as the treatment of physical and psychological symptoms arising from the disease. Non-randomized studies review To assess the safety of therapeutics for mpox infection from non-randomized studies (NRS).

SEARCH METHODS

Randomized controlled trials review We searched the following databases up to 25 January 2023: MEDLINE (OVID), Embase (OVID), Biosis previews (Web of Science), CAB Abstracts (Web of science), and Cochrane CENTRAL (Issue 1 2023). We conducted a search of trial registries (Clinicaltrials.gov and International Clinical Trials Registry Platform (ICTRP)) on 25 January 2023. There were no date or language limits placed on the search. We undertook a call to experts in the field for relevant studies or ongoing trials to be considered for inclusion in the review. Non-randomized studies review We searched the following databases on 22 September 2022: Cochrane Central Register of Controlled Trials (CENTRAL; Issue 9 of 12, 2022), published in the Cochrane Library; MEDLINE (Ovid); Embase (Ovid); and Scopus (Elsevier). We also searched the WHO International Clinical Trials Registry Platform and ClinicalTrials.gov for trials in progress.

SELECTION CRITERIA

For the RCT review and the narrative review, any therapeutic for the treatment of mpox in humans was eligible for inclusion, including tecovirimat, brincidofovir, cidofovir, NIOCH-14, immunomodulators, and vaccine immune globulin. Randomized controlled trials review Studies were eligible for the main review if they were of randomized controlled design and investigated the effectiveness or safety of therapeutics in human mpox infection. Non-randomized studies review Studies were eligible for inclusion in the review of non-randomized studies if they were of non-randomized design and contained data concerning the safety of any therapeutic in human mpox infection.

DATA COLLECTION AND ANALYSIS

Randomized controlled trials review Two review authors independently applied study inclusion criteria to identify eligible studies. If we had identified any eligible studies, we planned to assess the risk of bias, and report results with 95% confidence intervals (CI). The critical outcomes were serious adverse events, development of disease-related complications, admission to hospital for non-hospitalized participants, pain as judged by any visual or numerical pain scale, level of virus detected in clinical samples, time to healing of all skin lesions, and mortality. We planned to perform subgroup analysis to explore whether the effect of the therapeutic on the planned outcomes was modified by disease severity and days from symptom onset to therapeutic administration. We also intended to explore the following subgroups of absolute effects: immunosuppression, age, and pre-existing skin disease. Non-randomized studies review One review author applied study inclusion criteria to identify eligible studies and extracted data. Studies of a non-randomized design containing data on the safety of therapeutics could not be meta-analyzed due to the absence of a comparator; we summarized these data narratively in an appendix.

MAIN RESULTS

Randomized controlled trials review We did not identify any completed RCTs investigating the effectiveness of therapeutics for treating mpox for the main review. We identified five ongoing trials that plan to assess the effectiveness of one therapeutic option, tecovirimat, for treating mpox in adults and children. One of these ongoing trials intends to include populations with, or at greater risk of, severe disease, which will allow an assessment of safety in more vulnerable populations. Non-randomized studies review Three non-randomized studies met the inclusion criteria for the narrative review, concerning data on the safety of therapeutics in mpox. Very low-certainty evidence from non-randomized studies of small numbers of people indicates no serious safety signals emerging for the use of tecovirimat in people with mpox infection, but a possible safety signal for brincidofovir. All three participants who received brincidofovir had raised alanine aminotransferase (ALT), but not bilirubin, suggesting mild liver injury. No study reported severe drug-induced liver injury with brincidofovir.

AUTHORS' CONCLUSIONS

Randomized controlled trials review This review found no evidence from randomized controlled trials concerning the efficacy and safety of therapeutics in humans with mpox. Non-randomized studies review Very low-certainty evidence from non-randomized studies indicates no serious safety signals emerging for the use of tecovirimat in people with mpox infection. In contrast, very low-certainty evidence raises a safety signal that brincidofovir may cause liver injury. This is also suggested by indirect evidence from brincidofovir use in smallpox. This warrants further investigation and monitoring. This Cochrane Review will be updated as new evidence becomes available to assist policymakers, health professionals, and consumers in making appropriate decisions for the treatment of mpox.

Risk profile and mode of transmission of Mpox: A rapid review and individual patient data meta-analysis of case studies

Since May 2022, an outbreak of Mpox in non-endemic countries has become a potential public health threat. The objective of this rapid review was to examine the risk profile and modes of transmission of Mpox. PubMed, Web of Science, and Scopus were searched from inception through July 30 to collect case reports/series on patients with Mpox infection. For meta-analysis, data on the total number of participants and deaths by binary categories of exposure (age, sex, country, other co-infections or existing conditions, and mode of contagion) were used. A total of 62 studies (4659 cases) were included. Most cases came from Africa (84.3%), followed by Europe (13.9%). In 63.6% of the cases, the mode of contagion was human contact, while 22.8% of the cases were by animal contact, and 13.5% were unknown or not reported. The mortality rate was 6.5% throughout these studies. The risk of mortality was higher in the younger age group (risk difference: 0.19; 95% CI: 0.02-0.36), in cases with other co-infections or current chronic conditions (risk difference: 0.03; 95% CI: 0.01-0.05) and in the category of low- and middle-income countries (risk difference: 0.06; 95% CI: 0.05-0.08). There were no significant differences with respect to sex or mode of contagion. These results help to understand the major infection pathways and mortality risk profiles of Mpox and underscores the importance of preventing outbreaks in specific settings, especially in settings densely populated by children, such as day care centres and schools.

Nasal monkeypox virus infection successfully treated with cidofovir in a patient newly diagnosed with HIV

Monkeypox (MPXV) usually causes a mild and self-limited infection. To date there are no data about cidofovir for the treatment for MPXV in humans. We report a case of a 25 years-old Brazilian man with a concurrent diagnosis of acute HIV (human immunodeficiency virus) infection, primary syphilis and MPXV infection with a nasal lesion successfully treated with intravenous cidofovir.

Use of cidofovir in a patient with severe mpox and uncontrolled HIV infection

A 48-year-old man with poorly controlled HIV presented with severe human monkeypox virus (hMPXV) infection, having completed 2 weeks of tecovirimat at another hospital. He had painful, ulcerating skin lesions on most of his body and oropharyngeal cavity, with subsequent Ludwig's angina requiring repeated surgical interventions. Despite commencing a second, prolonged course of tecovirimat, he did not objectively improve, and new lesions were still noted at day 24. Discussion at the UK National Health Service England High Consequence Infectious Diseases Network recommended the use of 3% topical and then intravenous cidofovir, which was given at 5 mg/kg; the patient made a noticeable improvement after the first intravenous dose. He received further intravenous doses at 7 days and 21 days after the dose and was discharged at day 52. Cidofovir is not licensed for use in treatment of hMPXV infection. Data for cidofovir use in hMPXV are restricted to studies in animals. Four other documented cases of cidofovir use against hMPXV have been reported in the USA in 2022, but we present its first use in the UK. The scarcity of studies into the use of cidofovir in this condition clearly shows the need for robust studies to assess efficacy, optimum dosage, timing, and route of administration.

Monkeypox: a review of the 2022 outbreak

INTRODUCTION

In May 2022, the World Health Organisation declared a multi-country monkeypox outbreak in non-endemic countries following cases reported from 12 member states that were not endemic for monkeypox virus.

SOURCES OF DATA

Pubmed search.

AREAS OF AGREEMENT

The virology, epidemiology, transmission, incubation and aspects of infection control are described. Clinical features of previous and current outbreaks are described, with growing observations that the current outbreak presents with clinical features distinct from previous outbreaks.

AREAS OF CONTROVERSY

There are variations in clinical presentations seen in the current outbreak that have not been seen in prior outbreaks. More research is needed to investigate the reasons for these differences.

GROWING POINTS

The higher numbers of HIV-positive patients in the current outbreak has allowed better description of the disease in patients co-infected with HIV and monkeypox. The absence of more severe symptoms in HIV-positive patients in the current outbreak could possibly be due to the fact that most of these patients had well-controlled HIV, although further characterization of this cohort of patients would be useful.

AREAS FOR DEVELOPING RESEARCH

Current treatment and vaccination options have been extrapolated from studies of other Orthopox viruses. There remains a need for more data on the safety and efficacy of these options in the context of monkeypox infections.

The use of antivirals in the treatment of human monkeypox outbreaks: a systematic review

OBJECTIVES

Human monkeypox virus (MPXV) infection is a recently declared public health emergency of international concern by the World Health Organization. Besides, there is scant literature available on the use of antivirals in MPXV infection. This systematic review compiles all evidence of various antivirals used on their efficacy and safety and summarizes their mechanisms of action.

METHODS

A review was done of all original studies mentioning individual patient data on the use of antivirals in patients with MPXV infection.

RESULTS

Of the total 487 non-duplicate studies, 18 studies with 71 individuals were included. Tecovirimat was used in 61 individuals, followed by cidofovir in seven and brincidofovir (BCV) in three individuals. Topical trifluridine was used in four ophthalmic cases in addition to tecovirimat. Of the total, 59 (83.1%) were reported to have complete resolution of symptoms; one was experiencing waxing and waning of symptoms, only one (1.8%) had died, and the others were having a resolution of symptoms. The death was thought unrelated to tecovirimat. Elevated hepatic panels were reported among all individuals treated with BCV (leading to treatment discontinuation) and five treated with tecovirimat.

CONCLUSION

Tecovirimat is the most used and has proven beneficial in several aggravating cases. No major safety concerns were detected upon its use. Topical trifluridine was used as an adjuvant treatment option along with tecovirimat. BCV and cidofovir were seldom used, with the latter often being used due to the unavailability of tecovirimat. BCV was associated with treatment discontinuation due to adverse events.

Arabinofuranosyl Thymine Derivatives-Potential Candidates against Cowpox Virus: A Computational Screening Study

Cowpox is caused by a DNA virus known as the cowpox virus (CPXV) belonging to the Orthopoxvirus genus in the family Poxviridae. Cowpox is a zoonotic disease with the broadest host range among the known poxviruses. The natural reservoir hosts of CPXV are wild rodents. Recently, the cases of orthopoxviral infections have been increasing worldwide, and cowpox is considered the most common orthopoxviral infection in Europe. Cowpox is often a self-limiting disease, although cidofovir or anti-vaccinia gammaglobulin can be used in severe and disseminated cases of human cowpox. In this computational study, a molecular docking analysis of thymine- and arabinofuranosyl-thymine-related structures (1-21) on two cowpox-encoded proteins was performed with respect to the cidofovir standard and a 3D ligand-based pharmacophore model was generated. Three chemical structures (PubChem IDs: 123370001, 154137224, and 90413364) were identified as potential candidates for anti-cowpox agents. Further studies combining in vitro and in silico molecular dynamics simulations to test the stability of these promising compounds could effectively improve the future design of cowpox virus inhibitors, as molecular docking studies are not sufficient to consider a ligand a potential drug.

Synthesis of esters and amides of 2-aryl-1-hydroxy-4-methyl-1H-imidazole-5-carboxylic acids and study of their antiviral activity against orthopoxviruses

Smallpox was eradicated >40 years ago but it is not a reason to forget forever about orthopoxviruses pathogenic to humans. Though in 1980 the decision of WHO to cease vaccination against smallpox had seemed logical, it led to the decrease of cross immunity against other infections caused by orthopoxviruses. As a result, in 2022 the multi-country monkeypox outbreak becomes a topic of great concern. In spite of existing FDA-approved drugs for the treatment of such diseases, the search for new small-molecule orthopoxvirus inhibitors continues. In the course of this search a series of novel 2-aryl-1-hydroxyimidazole derivatives containing ester or carboxamide moieties in position 5 of heterocycle has been synthesized and tested for activity against Vaccinia virus in Vero cell culture. Some of the compounds under consideration revealed a selectivity index higher than that of the reference drug Cidofovir. The highest selectivity index SI = 919 was exhibited by ethyl 1-hydroxy-4-methyl-2-[4-(trifluoromethyl)phenyl]-1H-imidazole-5-carboxylate 1f. The most active compound also demonstrated inhibitory activity against the cowpox virus (SI = 20) and the ectromelia virus (SI = 46).

Insights into monkeypox pathophysiology, global prevalence, clinical manifestation and treatments

On 23rd July 2022, the World Health Organization (WHO) recognized the ongoing monkeypox outbreak as a public medical crisis. Monkeypox virus (MPV), the etiological agent of monkeypox, is a zoonotic, linear, double-stranded DNA virus. In 1970, the Democratic Republic of the Congo reported the first case of MPV infection. Human-to-human transmission can happen through sexual contact, inhaled droplets, or skin-to-skin contact. Once inoculated, the viruses multiply rapidly and spread into the bloodstream to cause viremia, which then affect multiple organs, including the skin, gastrointestinal tract, genitals, lungs, and liver. By September 9, 2022, more than 57,000 cases had been reported in 103 locations, especially in Europe and the United States. Infected patients are characterized by physical symptoms such as red rash, fatigue, backache, muscle aches, headache, and fever. A variety of medical strategies are available for orthopoxviruses, including monkeypox. Monkeypox prevention following the smallpox vaccine has shown up to 85% efficacy, and several antiviral drugs, such as Cidofovir and Brincidofovir, may slow the viral spread. In this article, we review the origin, pathophysiology, global epidemiology, clinical manifestation, and possible treatments of MPV to prevent the propagation of the virus and provide cues to generate specific drugs.

Potential therapeutic targets for Mpox: the evidence to date

INTRODUCTION

The global Mpox (MPX) disease outbreak caused by the Mpox virus (MPXV) in 2022 alarmed the World Health Organization (WHO) and health regulation agencies of individual countries leading to the declaration of MPX as a Public Health Emergency. Owing to the genetic similarities between smallpox-causing poxvirus and MPXV, vaccine JYNNEOS, and anti-smallpox drugs Brincidofovir and Tecovirimat were granted emergency use authorization by the United States Food and Drug Administration. The WHO also included cidofovir, NIOCH-14, and other vaccines as treatment options.

AREAS COVERED

This article covers the historical development of EUA-granted antivirals, resistance to these antivirals, and the projected impact of signature mutations on the potency of antivirals against currently circulating MPXV. Since a high prevalence of MPXV infections in individuals coinfected with HIV and MPXV, the treatment results among these individuals have been included.

EXPERT OPINION

All EUA-granted drugs have been approved for smallpox treatment. These antivirals show good potency against Mpox. However, conserved resistance mutation positions in MPXV and related poxviruses, and the signature mutations in the 2022 MPXV can potentially compromise the efficacy of the EUA-granted treatments. Therefore, MPXV-specific medications are required not only for the current but also for possible future outbreaks.

Monkeypox treatment: Current evidence and future perspectives

As of September 11, 2022, 57 669 reports of monkeypox infection raised global concern. Previous vaccinia virus vaccination can protect from monkeypox. However, after smallpox eradication, immunization against that was stopped. Indeed, therapeutic options following the disease onset are of great value. This study aimed to review the available evidence on virology and treatment approaches for monkeypox and provide guidance for patient care and future studies. Since no randomized clinical trials were ever performed, we reviewed monkeypox animal model studies and clinical trials on the safety and pharmacokinetics of available medications. Brincidofovir and tecovirimat were the most studied medications that got approval for smallpox treatment according to the Animal Rule. Due to the conserved virology among Orthopoxviruses, available medications might also be effective against monkeypox. However, tecovirimat has the strongest evidence to be effective and safe for monkeypox treatment, and if there is a choice between the two drugs, tecovirimat has shown more promise so far. The risk of resistance should be considered in patients who failed to respond to tecovirimat. Hence, the target-based design of novel antivirals will enhance the availability and spectrum of effective anti-Orthopoxvirus agents.

Monkeypox Virus Infections in Humans

Human monkeypox is a viral zoonosis endemic to West and Central Africa that has recently generated increased interest and concern on a global scale as an emerging infectious disease threat in the midst of the slowly relenting COVID-2019 disease pandemic. The hallmark of infection is the development of a flu-like prodrome followed by the appearance of a smallpox-like exanthem. Precipitous person-to-person transmission of the virus among residents of 100 countries where it is nonendemic has motivated the immediate and widespread implementation of public health countermeasures. In this review, we discuss the origins and virology of monkeypox virus, its link with smallpox eradication, its record of causing outbreaks of human disease in regions where it is endemic in wildlife, its association with outbreaks in areas where it is nonendemic, the clinical manifestations of disease, laboratory diagnostic methods, case management, public health interventions, and future directions.

Therapeutic strategies for human poxvirus infections: Monkeypox (mpox), smallpox, molluscipox, and orf

Therapeutic and vaccine development for human poxvirus infections (e.g., monkeypox (mpox) virus, variola virus, molluscum contagiosum virus, orf virus) has been largely deserted, especially after the eradication of smallpox by 1980. Human mpox is a self-limited disease confined to Central and West Africa for decades. However, since April 2022, mpox has quickly emerged as a multi-country outbreak, urgently calling for effective antiviral agents and vaccines to control mpox. Here, this review highlights possible therapeutic options (e.g., tecovirimat, brincidofovir, cidofovir) and other strategies (e.g., vaccines, intravenous vaccinia immune globulin) for the management of human poxvirus infections worldwide.

Pharmacological Agents with Antiviral Activity against Monkeypox Infection

Monkeypox infection is caused by a virus of the genus Orthopoxvirus, a member of the Poxviridae family. Monkeypox virus is transmitted from individual to individual through contact with lesions, body fluids, and respiratory droplets. The infection caused by monkeypox is usually a self-limited disease with mild symptoms lasting 2 to 4 weeks. Monkeypox typically presents with fever, rash, and enlarged lymph nodes. New vaccines have recently been authorized for the prevention of monkeypox infection, whereas there are no specific pharmacological antiviral treatments for monkeypox infection. However, because the viruses which cause adult smallpox and monkeypox are similar, antiviral drugs developed in the past have also shown efficacy against monkeypox. In this review, we highlight the in vitro and clinical evidence found in the literature on the efficacy and safety of pharmacological agents with antiviral activity against monkeypox infection and the different regulatory aspects of countries.

An Update on the Pharmacological Aspects of Vaccines and Antivirals for the Management of Monkeypox

Monkeypox is a self-limiting zoonotic disease caused by the monkeypox virus belonging to the genus of orthopox viruses. Initially considered an ‘African disease’, this infection has crossed the boundaries to affect other continents and it has raised tremendous concerns among the general public as well as the medical fraternity all over the world, particularly because of the lack of specific vaccinations and drugs for the management of the illness. Epidemiological evaluation of the current infection has reported that it is mainly transmitted through sexual contact in bisexual men, mostly whites, and in those with pre-existing human immunodeficiency virus infection. The most common presentations were skin rash, anogenital lesions, or mucosal lesions along with systemic symptoms. It has been established that the vaccines and drugs approved for the management of smallpox could be used for the management of the current monkeypox outbreak. Vaccinia Immune Globulin (VIG) and vaccines like JYNNEOS and ACAM2000 and antiviral drugs like tecovirimat, cidofovir (CDV), and brincidofovir are being considered for those patients with serious diseases. It is imperative for physicians to understand the pharmacological aspects of these drugs for delivering better care to patients with monkeypox, which is eventually essential for the containment of this infection. This review covers updates on vaccines as well as drugs for the prevention and management of monkeypox.

Mutations in the monkeypox virus replication complex: Potential contributing factors to the 2022 outbreak

Attributes contributing to the current monkeypox virus (MPXV) outbreak remain unknown. It has been established that mutations in viral proteins may alter phenotype and pathogenicity. To assess if mutations in the MPXV DNA replication complex (RC) contribute to the outbreak, we conducted a temporal analysis of available MPXV sequences to identify mutations, generated a DNA replication complex (RC) using structures of related viral and eukaryotic proteins, and structure prediction method AlphaFold. Ten mutations within the RC were identified and mapped onto the RC to infer role of mutations. Two mutations in F8L (RC catalytic subunit), and two in G9R (a processivity factor) were ∼100% prevalent in the 2022 sequences. F8L mutation L108F emerged in 2022, whereas W411L emerged in 2018, and persisted in 2022. L108 is topologically located to enhance DNA binding affinity of F8L. Therefore, mutation L108F can change the fidelity, sensitivity to nucleoside inhibitors, and processivity of F8L. Surface exposed W411L likely affects the binding of regulatory factor(s). G9R mutations S30L and D88 N in G9R emerged in 2022, and may impact the interaction of G9R with E4R (uracil DNA glycosylase). The remaining six mutations that appeared in 2001, reverted to the first (1965 Rotterdam) isolate. Two nucleoside inhibitors brincidofovir and cidofovir have been approved for MPXV treatment. Cidofovir resistance in vaccinia virus is achieved by A314T and A684V mutations. Both A314 and A684 are conserved in MPXV. Therefore, resistance to these drugs in MPXV may arise through similar mechanisms.

Clinical manifestations of human monkeypox infection and implications for outbreak strategy

Monkeypox is an orthopoxvirus-based zoonotic illness that causes symptoms similar to smallpox in humans. Health care workers around the world are making it a priority to educate themselves on the many clinical manifestations and treatment options for this virus as public health agencies strive to stop the current outbreak. The infected do not have access to any treatment at this time. However, information obtained from the smallpox pandemic has led researchers to examine vaccinia immune globulin (IVG), tecovirimat, and cidofovir as viable treatments for monkeypox. Moreover, medication like tecovirimat may be given in extreme circumstances, and supportive therapy can help with symptom relief. The European Medicines Agency (EMA) certified tecovirimat as safe and effective against monkeypox in 2022, per the World Health Organization (WHO). As there are now no established guidelines for alleviating these symptoms, the efficacy of these treatments is highly questionable. Some high-profile cases in recent years have cast doubt on the long-held belief that this illness is rare and always resolves itself without treatment. We aimed to conduct this review to get a deeper comprehension of the evolving epidemiology of monkeypox by analysing such factors as the number of confirmed, probable, and potential cases, the median age at presentation, the mortality rate, and the geographic distribution of the disease. This study offers an updated review of monkeypox and the clinical treatments that are currently available as a result of the worldwide epidemics.

The evolving epidemiology of monkeypox virus

Monkeypox, caused by the monkeypox virus (MPXV), is a zoonotic disease endemic mainly in West and Central Africa. As of 27 September 2022, human monkeypox has occurred in more than 100 countries (mostly in non-endemic regions) and caused over 66,000 confirmed cases, which differs from previous epidemics that mainly affected African countries. Due to the increasing number of confirmed cases worldwide, the World Health Organization (WHO) has declared the monkeypox outbreak as a Public Health Emergency of International Concern on July 23, 2022. The international outbreak of human monkeypox represents a novel route of transmission for MPXV, with genital lesions as the primary infection, and the emergence of monkeypox in the current outbreak is also new, as novel variants emerge. Clinical physicians and scientists should be aware of this emerging situation, which presents a different scenario from previous outbreaks. In this review, we will discuss the molecular virology, evasion of antiviral immunity, epidemiology, evolution, and detection of MPXV, as well as prophylaxis and treatment strategies for monkeypox. This review also emphasizes the integration of relevant epidemiological data with genomic surveillance data to obtain real-time data, which could formulate prevention and control measures to curb this outbreak.

Prevention and Treatment of Monkeypox: A Systematic Review of Preclinical Studies

The outbreak of monkeypox, coupled with the onslaught of the COVID-19 pandemic is a critical communicable disease. This study aimed to systematically identify and review research done on preclinical studies focusing on the potential monkeypox treatment and immunization. The presented juxtaposition of efficacy of potential treatments and vaccination that had been tested in preclinical trials could serve as a useful primer of monkeypox virus. The literature identified using key terms such as monkeypox virus or management or vaccine stringed using Boolean operators was systematically reviewed. Pubmed, SCOPUS, Cochrane, and preprint databases were used, and screening was performed in accordance with PRISMA guidelines. A total of 467 results from registered databases and 116 from grey literature databases were screened. Of these results, 72 studies from registered databases and three grey literature studies underwent full-text screening for eligibility. In this systematic review, a total of 27 articles were eligible according to the inclusion criteria and were used. Tecovirimat, known as TPOXX or ST-246, is an antiviral drug indicated for smallpox infection whereas brincidofovir inhibits the viral DNA polymerase after incorporation into viral DNA. The ability of tecovirimat in providing protection to poxvirus-challenged animals from death had been demonstrated in a number of animal studies. Non-inferior with regard to immunogenicity was reported for the live smallpox/monkeypox vaccine compared with a single dose of a licensed live smallpox vaccine. The trial involving the live vaccine showed a geometric mean titre of vaccinia-neutralizing antibodies post two weeks of the second dose of the live smallpox/monkeypox vaccine. Of note, up to the third generation of smallpox vaccines-particularly JYNNEOS and Lc16m8-have been developed as preventive measures for MPXV infection and these vaccines had been demonstrated to have improved safety compared to the earlier generations.

Monkeypox: epidemiology, pathogenesis, treatment and prevention

Monkeypox is a zoonotic disease that was once endemic in west and central Africa caused by monkeypox virus. However, cases recently have been confirmed in many nonendemic countries outside of Africa. WHO declared the ongoing monkeypox outbreak to be a public health emergency of international concern on July 23, 2022, in the context of the COVID-19 pandemic. The rapidly increasing number of confirmed cases could pose a threat to the international community. Here, we review the epidemiology of monkeypox, monkeypox virus reservoirs, novel transmission patterns, mutations and mechanisms of viral infection, clinical characteristics, laboratory diagnosis and treatment measures. In addition, strategies for the prevention, such as vaccination of smallpox vaccine, is also included. Current epidemiological data indicate that high frequency of human-to-human transmission could lead to further outbreaks, especially among men who have sex with men. The development of antiviral drugs and vaccines against monkeypox virus is urgently needed, despite some therapeutic effects of currently used drugs in the clinic. We provide useful information to improve the understanding of monkeypox virus and give guidance for the government and relative agency to prevent and control the further spread of monkeypox virus.

Reemergence of monkeypox: prevention and management

INTRODUCTION

The reemergence of monkeypox virus in the twenty-first century, calls for an urgency in its control and preventive measures. There is a long-standing concern that the reemergence of monkeypox across countries could lead to another epidemic like the COVID-19 pandemic. Understanding the disease ecology, preventing its transmission could help curbing its spread. The established treatment protocols along with development of new antiviral agents and vaccines could play a pivotal role in controlling its transmission.

AREAS COVERED

In this review, we summarize the different modes of transmission of this disease, the associated symptoms, the standard protocol of treatment, the available vaccines and use of alternative treatments. We have collated recent research on novel entities that could potentially treat monkeypox infection.

EXPERT OPINION

The One Health approach fostered by the World Health Organization (WHO) for emergent and reemerging zoonotic diseases has to be implemented with a view to curb their transmission. The growing global population and increased inter-country travel has led to rapid spread of transmissible pathogens. Stigmatization, associated with lack of knowledge can be prevented by enhancing awareness campaigns. Vaccines need to be administered to high-risk individuals, and drug discovery efforts need to be intensified to combat such diseases.

Strategy of developing nucleic acid-based universal monkeypox vaccine candidates

Until May 2022, zoonotic infectious disease monkeypox (MPX) caused by the monkeypox virus (MPXV) was one of the forgotten viruses considered to be geographically limited in African countries even though few cases outside of Africa were identified. Central and West African countries are known to be endemic for MPXV. However, since the number of human MPX cases has rapidly increased outside of Africa the global interest in this virus has markedly grown. The majority of infected people with MPXV have never been vaccinated against smallpox virus. Noteworthily, the MPXV spreads fast in men who have sex with men (MSM). Preventive measures against MPXV are essential to be taken, indeed, vaccination is the key. Due to the antigenic similarities, the smallpox vaccine is efficient against MPXV. Nevertheless, there is no specific MPXV vaccine until now. Nucleic acid vaccines deserve special attention since the emergency approval of two messenger RNA (mRNA)-based coronavirus disease 2019 (COVID-19) vaccines in 2020. This milestone in vaccinology has opened a new platform for developing more mRNA- or DNA-based vaccines. Certainly, this type of vaccine has a number of advantages including time- and cost-effectiveness over conventional vaccines. The platform of nucleic acid-based vaccines gives humankind a huge opportunity. Ultimately, there is a strong need for developing a universal vaccine against MPXV. This review will shed the light on the strategies for developing nucleic acid vaccines against MPXV in a timely manner. Consequently, developing nucleic acid-based vaccines may alleviate the global threat against MPXV.

Comprehensive Literature Review of Monkeypox

The current outbreak of monkeypox (MPX) infection has emerged as a global matter of concern in the last few months. MPX is a zoonosis caused by the MPX virus (MPXV), which is one of the Orthopoxvirus species. Thus, it is similar to smallpox caused by the variola virus, and smallpox vaccines and drugs have been shown to be protective against MPX. Although MPX is not a new disease and is rarely fatal, the current multi-country MPX outbreak is unusual because it is occurring in countries that are not endemic for MPXV. In this work, we reviewed the extensive literature available on MPXV to summarize the available data on the major biological, clinical and epidemiological aspects of the virus and the important scientific findings. This review may be helpful in raising awareness of MPXV transmission, symptoms and signs, prevention and protective measures. It may also be of interest as a basis for performance of studies to further understand MPXV, with the goal of combating the current outbreak and boosting healthcare services and hygiene practices.Trial registration: ClinicalTrials.gov identifier: NCT02977715..Trial registration: ClinicalTrials.gov identifier: NCT03745131..Trial registration: ClinicalTrials.gov identifier: NCT00728689..Trial registration: ClinicalTrials.gov identifier: NCT02080767..

Monkeypox as an emerging infectious disease: the ophthalmic implications

The 2022 outbreak of monkeypox is of worldwide significance. There has been a rapid escalation in case numbers despite efforts to contain it and the WHO has declared it a Public Health Emergency of International Concern. To date, over 51 257 laboratory-confirmed cases have been reported, the majority in non-endemic countries, with 3279 in the UK. It is vital for ophthalmologists to understand this disease and the risk it poses. Human monkeypox is a zoonotic disease caused by the monkeypox virus, a double-stranded DNA virus in the Orthopoxvirus genus of the Poxviridae family. Other orthopoxviruses include variola (smallpox), cowpox and vaccinia; all of which have significant ocular sequelae. Transmission occurs from an animal reservoir (unknown, likely rodents) to a human host, leading to secondary human-to-human spread. During the recent outbreak, a higher incidence has been found in gay, bisexual or other men who have sex with men. Clinical diagnosis may be challenging as presentation can mimic common ophthalmic diseases. A thorough history is key to identifying potential cases. Ophthalmic manifestations may include preseptal cellulitis, conjunctivitis and keratitis. The oral antiviral agent tecovirimat, which was developed to treat smallpox, is the mainstay of treatment. Trifluorothymidine (trifluridine) eye-drops can be used for ophthalmic involvement. In addition, smallpox vaccines have provided some cross-immunity. Ocular monkeypox should be managed by infectious diseases specialists, in consultation with ophthalmologists to provide the expertise needed to treat potentially vision-threatening complications. This outbreak highlights the need for healthcare providers to implement appropriate infection control measures and be familiar with the identification and treatment of both cutaneous and ocular disease.