A tale of two clades: monkeypox viruses

A functional approach to analyze the genetic basis for differences in virulence of monkeypox virus clades

Mpox, the disease caused by monkeypox virus (MPXV) is increasing in Africa and in 2022 spread to more than 100 countries sickening more than 100,000 individuals. Four clades of MPXV have been recognized with differences in severity of disease and extent of human-to-human transmission. Determination of the genetic basis for these differences could help to develop improved therapeutics and vaccines. The Castaneous (CAST) mouse is highly susceptible to MPXV and virulence differences of MPXV clades are statistically significant mimicking their relative severities in humans. The present study was intended to evaluate the CAST mouse as a model for investigating genomic differences by replacing genes of Zaire-1979 005 (Z-79) clade Ia MPXV with homologous gene sequences of the less virulent and less transmissible USA-2003 clade IIa MPXV. The expectation was that some gene replacements would reduce the virulence of Z-79 chimera. Recombinant viruses expressing firefly luciferase were constructed in which partially overlapping Z-79 DNA segments of 5,000 to 13,000 bp containing ∼ 40 genes in total from the two ends of MPXV-79 were replaced with corresponding segments of USA-2003. Virulence was determined by live animal imaging in addition to weight loss and survival. Although there were statistical differences in survival and viral luminescence between the clade Ia and clade IIa MPXVs, no significant difference was found by replacing individual or multiple genes of clade Ia Z-79 with corresponding genes of clade IIa USA-2003. The absence of a significant reduction in virulence can have several explanations that would inform future experiments.

Mpox virus (MPXV): comprehensive analysis of pandemic risks, pathophysiology, treatments, and mRNA vaccine development

Mpox, formerly known as monkeypox, is a zoonotic disease caused by the Mpox virus (MPXV), which has recently attracted global attention due to its potential for widespread outbreaks. Initially identified in 1958, MPXV primarily spreads to humans through contact with infected wild animals, particularly rodents. Historically confined to Africa, the virus has expanded beyond endemic regions, with notable outbreaks in Europe and North America in 2022, especially among men who have sex with men (MSM). The World Health Organization (WHO) has declared the current Mpox outbreak a Public Health Emergency of International Concern. This review explores the epidemiology, pathophysiology, and clinical manifestations of MPXV, along with current treatment strategies and the role of mRNA vaccines. It emphasizes the importance of understanding the changing dynamics of Mpox transmission, which are influenced by factors such as waning immunity from smallpox vaccinations and increased global interconnectedness. The potential for developing multi-epitope vaccines that can stimulate robust immune responses is highlighted, showcasing how bioinformatics can facilitate the identification of immunogenic antigens. Continued research and investment in vaccine development are crucial to address the urgent need for effective candidates that can protect at-risk populations. In summary, this review underscores the necessity for proactive public health measures and collaborative efforts among healthcare authorities, researchers, and communities to mitigate the impact of Mpox and enhance global preparedness for future outbreaks.

Emergence of mpox in Oman: investigating the first cluster and its implications, October 2023

Objectives

The mpox virus, a member of the orthopoxvirus genus of the Poxviridae family, is the source of this newly recognized viral zoonotic illness. Before October 2023, no mpox cases were reported in Oman. This study describes the first confirmed case of mpox and a related family cluster from North Batinah Governorate. This study aimed to describe the clinical and epidemiologic investigations of the first mpox case and cluster in Oman, including the identification of infection sources; assessing the transmission prevention measures in place for health care settings and the community; and providing recommendations for improving public health measures for the prevention, detection, and response to the emerging threat of mpox.

Methods

An outbreak investigation study was conducted involving all three confirmed cases of mpox in October 2023 in North Batinah Governorate, using a previously prepared form for epidemiological investigation of the cases and another form for detailed contact tracing.

Results

The results showed that all three cases were from the same family from Sohar Willayat infected with mpox clade IIb. The possible source of infection for the index case was not declared but was potentially travel-related. Transmission to secondary cases occurs through droplets, direct contact, and bedding within households. All contacts were identified and followed up for 21 days, and no secondary cases occurred outside the household.

Conclusions

Travel-related exposure appeared to be a significant factor in the outbreak of clade IIb in Oman. This investigation serves as a practical exercise for public health preparedness, emphasizing the importance of an adaptive health system. Ensuring robust detection and response measures while accounting for patient privacy, cultural contexts, and available resources, such as institutional quarantine for contacts, is crucial for effectively managing emerging infectious diseases.

Mpox: Characterization and clinical outcomes of patients in Colombian healthcare institutions

Introduction

In 2022, the world experienced a monkeypox outbreak caused by the Clade IIb strain of the virus. While this outbreak had widespread effects, more information is needed on mpox's specific impact in Colombia, particularly regarding how it is managed, its burden, and its epidemiology. This research seeks to examine the medical context, clinical presentation, and health outcomes of individuals diagnosed with mpox infection, with a particular focus on those with HIV in Colombia.

Methods

This retrospective study was conducted in fourteen Health institutions in Colombia based on computerized clinical records from Jan 2022 to Dec 2023. Clinical and epidemiological characteristics were collected from diagnosis until discharge (or death). Participants in the study were diagnosed through molecular methods (PCR) and their clinical evolution was tracked through hospital and/or outpatient medical records. Registered variables were based on the mpox 2023 Case Report Form (2023 - CRF) proposed by the World Health Organization.

Results

One thousand four hundred thirteen (1413, 97.2 % male) individuals, including 2.6 % identified as healthcare workers, were included in this study. The majority (54 %, 764/1413 individuals) were persons living with HIV (PWH) and almost one-third of them (30.1 %, n = 284) of participants had concomitant sexually transmitted diseases and HIV, with syphilis being the most prevalent (20.4 %), followed by Neisseria gonorrhoeae (16.4 %). Complications were infrequent, with cellulitis being the most common, and no individuals received mpox-specific treatment or vaccination. Although all individuals had skin lesions distributed across various body regions, differences were noted in lesion distribution among women. Those living with HIV showed higher emergency department attendance and reported having known mpox contacts. While complications were rare, with cellulitis being the most common, women living with HIV showed a higher rate of emergency room visits and known mpox contacts. Although not statistically significant, gastrointestinal, musculoskeletal, psychological, respiratory, and STI symptoms, including syphilis and urethritis, were more common in the virologically non-suppressed HIV group. At the same time, proctitis was more prevalent in the suppressed group. No significant differences were found based on CD4 count, using 200 cells/mm3 in PWH.

Conclusion

Over half of the participants were people living with HIV (PWH), with a significant presence of STIs like syphilis. While skin lesions and complications varied, no significant differences were linked to CD4 count or viral load suppression. Mpox symptomatology was not significantly associated with unsuppressed viral loads or low CD4 levels, highlighting the need for further research.

[From endemic to pandemic Mpox virus infection]

The Mpox virus is an Orthopoxvirus that typically causes benign pustular skin lesions, but can also lead to rare cases of invasive disease. In 2022, clade IIb of this zoonotic virus, endemic to West and Central Africa, spread globally, resulting in 99,176 cases across 116 countries. In 2024, a rapid surge in clade Ib infections in Central Africa, followed by the first European cases - most notably in France on January 6, 2025 - raised concerns about the risk of a new pandemic outbreak. This review article aims to summarize current knowledge on Mpox virus infection, providing insights that may prove valuable in the event of a confirmed pandemic.

Mpox multiprotein virus-like nanoparticle vaccine induces neutralizing and protective antibodies in mice and non-human primates

The upsurge of mpox in Africa and the recent global outbreak have stimulated the development of new vaccines and therapeutics. We describe the construction of virus-like particle (VLP) vaccines in which modified M1, A35 and B6 proteins from monkeypox virus (MPXV) clade Ia are conjugated individually or together to a scaffold that accommodates up to 60 ligands using the SpyTag/SpyCatcher nanoparticle system. Immunisation of female mice with VLPs induces higher anti-MPXV and anti-vaccinia virus (VACV) neutralizing antibodies than their soluble protein (SP) counterparts or modified VACV Ankara (MVA). Vaccination with individual single protein VLPs provides partial protection against lethal respiratory infections with VACV or MPXV clade IIa, whereas combinations or a chimeric VLP with all three antigens provide complete protection that is superior to SPs. Additionally, the VLP vaccine reduces the replication and spread of the virus at intranasal and intrarectal sites of inoculation. VLPs induce higher neutralizing activity than the Jynneos vaccine in rhesus macaques, and the VLP-induced antiserum provides better protection against MPXV and VACV than the Jynneos-induced antiserum when passively transferred to female mice. These data demonstrate that an mpox VLP vaccine derived from three MPXV clade Ia proteins protects against clade IIa MPXV and VACV, indicating cross-reactivity for orthopoxviruses.

Genomic Evolution and Epidemiological Impact of Ongoing Clade Ib MPox Disease: A Narrative Review

Clade 1b of the MPox virus has emerged as a highly virulent strain, causing significant public health challenges globally. Initially endemic to Central Africa, this strain has spread to nonendemic regions, including Europe, Asia, and the Americas. With its high transmission rate and severe outcomes, especially among vulnerable populations like children, Clade 1b has raised global concerns. The Africa Center for Disease Control and Prevention (CDC) has declared it a public health emergency of international concern. Clade 1b MPox shows a higher case fatality rate and increased transmissibility compared to other strains. It has moved beyond traditional zoonotic transmission to widespread human-to-human transmission. The variant's spread to countries such as Sweden and Thailand demonstrates its global reach. Public health efforts, including cross-border coordination, rapid response teams, and awareness campaigns, have been essential in containing the outbreaks. However, barriers such as limited resources, vaccine shortages, and logistical challenges in conflict-affected areas have hindered effective control, particularly in low-resource regions. The spread and severity of Clade 1b MPox highlight the need for global cooperation to strengthen surveillance, improve diagnostic capabilities, and expand healthcare infrastructure in affected areas. Enhancing access to vaccines and treatments, along with educating the public on preventive measures, will be key to controlling transmission. Ongoing research and monitoring are essential to mitigate future outbreaks and minimize the virus's global impact.

Differences in Mpox and Vaccinia Immunity Induced by Non-Replicating and Replicating Vaccinia-Based Vaccines

Background: The recent global outbreak with clade IIb and the concurrent emergence of clade I mpox virus in Africa show that mpox is a challenging problem. MVA-BN induces low-level mpox-neutralizing antibody responses that wane rapidly. This study was conducted to compare the mpox immunity induced by a replication-competent smallpox vaccine and non-replicating MVA-BN. Methods: Stored sera (n = 302) and PBMCs (n = 244) collected pre-vaccination and at five post-vaccination time points in MVA-BN and six post-vaccination time points in Dryvax clinical trials were used. Antibody titers that neutralized at least 50% of mpox in cell culture were determined by the focus reduction neutralization test (FRNT) 50, and the mpox-specific T cell responses were measured using an IFN-γ ELISPOT assay. Results: The peak geometric fold rise (95% CI) (i.e., the maximum GMFR across all study visits) in the mpox FRNT50 for subcutaneous (SC) MVA-BN, intradermal (ID) MVA-BN, and Dryvax was 22.1 (8.3, 59.1), 18.5 (8.0, 43.1), and 245.8 (100.4, 601.6), respectively. The GMFR at day 180 post-vaccination for MVA-BN (SC), MVA-BN (ID), and Dryvax was 2.4, 2.7, and 64, respectively. The mean (95% CI) peak number of mpox-specific IFN-γ-producing SFCs was 127 (43.1, 238.3), 87.3 (46, 137), and 61.2 (44.3, 77.7) for MVA-BN (SC), MVA-BN (ID), and Dryvax, respectively. On day 180, the mean SFCs in the three groups decreased to 10.8 (-34.4, 3.8), 3.3 (-6.2, 18.6), and 2.2 (-9, 12.5), respectively. Conclusions: The peak mpox-neutralizing antibody titer was >10-fold lower in MVA-BN recipients compared to those who received a replication-competent smallpox vaccine, and the level at day 180 was >20 times lower in MVA-BN recipients. MVA-BN induced similar or higher T cell responses.

Drug screen reveals new potent host-targeted antivirals against Mpox virus

Mpox virus (MPXV), a re-emerging zoonotic threat, has caused outbreaks in non-endemic regions through respiratory, sexual, and close-contact transmission. The increased transmissibility of Clade IIb fueled the 2022 global outbreak, with 2024 Clade Ib spread in the Democratic Republic of Congo further escalating concern. Both outbreaks were declared public health emergencies by the WHO. Although tecovirimat (TPOXX) has been used off-label for Mpox, its limited effectiveness highlights the critical need for newer antivirals for MPXV. We conducted high-throughput antiviral drug screening using a host-directed kinase inhibitor library composed of 2,750 compounds against 2022 Clade IIb MPXV. Our primary screen identified 138 compounds preventing MPXV cytopathic effects, including multiple inhibitors of EGFR, PI3K-mTOR, and Ras/Raf, as well as apoptosis and autophagy regulators. Secondary and tertiary screenings yielded a shortlist of potent, nontoxic antiviral compounds that inhibited MPXV replication. Three selected compounds, IRAK4-IN-6, SM-7368, and KRAS inhibitor-10, reduced MPXV-induced cell death in primary human epidermal keratinocytes. IRAK4-IN-6 and SM-7368 were also found to modulate NF-κB and STING signaling. Furthermore, these compounds were found effective in reducing skin lesions and viral burden in a mouse model of MPXV skin infection. Together, our study reveals new classes of antiviral compounds against MPXV, offering promising candidates for future clinical development.

Mpox in pregnancy: Unraveling the maternal-fetal risks of a re-emerging disease, a narrative review

Mpox has re-emerged, particularly with the spread of Clade Ib in 2024 and recent outbreaks have raised concerns about its impact on pregnant women. Limited data suggest increased risks of adverse outcomes such as stillbirths and miscarriages, but understanding of mpox in pregnancy remains incomplete. A narrative review of literature was conducted, focusing on maternal-fetal transmission and the implications of different MPXV clades. The spread of Clade Ib, first identified in 2023, has heightened concerns about vertical transmission, particularly in rural African regions where access to diagnostic tools and treatments is limited. The risk of vertical transmission has become a pressing concern, considering the high transmission rates of Clade Ib. Despite limited data, maternal-fetal transmission has been documented, with serious fetal outcomes such as stillbirths and hydrops fetalis. Continued research and surveillance are critical to developing effective clinical guidelines and public health interventions, especially for managing mpox in pregnancy.

Mpox and the impact on people with HIV

PURPOSE OF REVIEW

This review explores the intersection of Mpox and HIV, highlighting clinical manifestations, immune evasion mechanisms, epidemiological challenges, and prevention strategies. People with HIV (PWH), particularly those with low CD4 + cell count, face severe Mpox outcomes. Prevention relies on education, vaccination, and early detection. Integrating Mpox management into HIV care systems is vital.

RECENT FINDINGS

Since May 2022, Mpox caused by Orthopoxvirus monkeypox (MPV) Clade IIb, has affected 126 countries. In 2024, Clade Ib emerged in the Democratic Republic of Congo, leading to its declaration as a Public Health Emergency of International Concern (PHEIC). Research on MPV-HIV co-infections has provided genomic insights and protective strategies for PWH. Antivirals like tecovirimat show promise despite emerging resistance concerns.

SUMMARY

The global Mpox outbreak caused by Clade IIb and the emergence of Clade Ib underscores its growing threat. Mpox disproportionately impacts PWH, leading to severe outcomes and higher fatality rates. This review emphasizes clinical challenges, genomic advances, and prevention strategies. Enhanced surveillance, vaccination, and tailored therapies are essential to addressing this evolving health crisis.

Isolation and Characterization of E8 Monoclonal Antibodies from Donors Vaccinated with Recombinant Vaccinia Vaccine with Efficient Neutralization of Authentic Monkeypox Virus

BACKGROUND/OBJECTIVES

Monkeypox, twice declared a public health emergency of international concern by the WHO, currently lacks approved targeted therapeutics. This study focused on the development of monkeypox virus (MPXV) E8-specific human monoclonal antibodies (mAbs) derived from recipients of the recombinant vaccinia vaccine (rTV), with subsequent evaluation of their cross-neutralizing activity against orthopoxviruses, including the vaccinia virus (VACV) and MPXV.

METHODS

Three mAbs (C5, C9, and F8) were isolated from rTV vaccinees. Structural mapping characterized their binding domains on the MPXV E8 and VACV D8 proteins. Neutralization potency was assessed against the VACV TianTan strain and MPXV clade IIb. A combo was further evaluated in a VACV-infected mice model for clinical recovery and viral load reduction. Complement-dependent enhancement mechanisms were also investigated in vitro.

RESULTS

C9 targets the virion surface region of E8 and both the virion surface region and intravirion region of D8, showing cross-neutralization activity against the MPXV (IC50 = 3.0 μg/mL) and VACV (IC50 = 51.1 ng/mL) in vitro. All three antibodies demonstrated potent neutralization against the VACV in vitro: C5 (IC50 = 3.9 ng/mL), C9 (IC50 = 51.1 ng/mL), and F8 (IC50 = 101.1 ng/mL). Notably, complement enhanced neutralization against the VACV by >50-fold, although no enhancement was observed for the MPXV. In vivo administration accelerated clinical recovery by 24 h and achieved significant viral clearance (0.9-log reduction).

CONCLUSIONS

E8-targeting mAbs exhibited broad-spectrum neutralization against orthopoxviruses, demonstrating therapeutic potential against both historical (VACV) and emerging (MPXV) pathogens. However, MPXV's resistance to complement-dependent enhancement highlights the necessity for pathogen-adapted optimization. These findings establish E8 as a critical conserved target for pan-poxvirus VACV and MPXV countermeasure development.

Comparative pathogenicity of vaccinia virus and mpox virus infections in CAST/EiJ mice: Exploring splenomegaly and transcriptomic profiles

BACKGROUND

Vaccinia virus (VACV) and mpox virus (MPXV) belong to the orthopoxvirus genus and share high genetic similarity, making VACV widely used in the mpox pandemic. CAST/EiJ mice have been widely used for studying orthopoxvirus infection. However, the histopathological features of CAST/EiJ mice with mpox virus (MPXV) and vaccinia virus (VACV) infections have not been fully elucidated.

METHODS

Four group of CAST/EiJ mice were challenged with low-dose VACV (103 PFU, VACV-L), high-dose VACV (106 PFU, VACV-H), MPXV (106 PFU) or PBS via intraperitoneal route, and the disease signs and body weight were monitored daily. Subsequently, viral loads and titers in the blood and spleen of CAST/EiJ mice were analyzed via qPCR and TCID50 assay. Finally, the spleen samples were analyzed for histopathological, immunohistochemical and RNA-seq.

RESULTS

Herein, we found that VACV-L and MPXV caused splenomegaly via the intraperitoneal route, whereas VACV-H caused rapid lethality with limited splenomegaly. Transcriptome analysis from spleen revealed significant differences in gene expression between VACV-L and VACV-H groups, but the differentially expressed genes induced by splenomegaly between VACV-L and MPXV groups were highly similar. Furthermore, pathway enrichment analysis demonstrated that the VACV-L, VACV-H, and MPXV groups were all associated with the calcium, MAPK, and PI3K-Akt signaling pathway. Compared to the lethal infection observed in VACV-H group, the splenomegaly in the VACV-L and MPXV groups was characterized by extramedullary hematopoiesis and increased macrophages infiltration in the red pulp. Transcriptome analysis of the spleen demonstrated that the Wnt, tumor necrosis factor (TNF), and transforming growth factor β (TGF-β) signaling pathways may promote splenomegaly by modulating granulocyte infiltration and inflammatory responses. Compared to VACV-L group, the limited splenomegaly but lethality in VACV-H-infected mice might be associated with extensive splenic necrosis, diffuse congestion, and hemorrhage in the red pulp, as well as changes in the cGMP-PKG, Ras signaling, and Fc gamma R-mediated phagocytosis pathways.

CONCLUSIONS

Our findings systematically compared the pathogenicity of VACV and MPXV in CAST/EiJ mice, incorporating splenic transcriptome analysis to provide insights into the potential molecular mechanism behind orthopoxvirus-induced splenomegaly in CAST/EiJ mice.

Emergence and evolution of monkeypox virus: Epidemiology, pathology, clinical symptoms, preventative and treatment measures

As the COVID-19 pandemic situation was on an end, a new monkeypox menace has been discovered in several places of the world. The most comforting thing is that the fatality rate of monkeypox is unlike Covid-19. But the recent global outbreaks and the rise in the number of cases has drawn attention of world towards it. The number of cases in multiple countries have already surpassed 25,000, according to the WHO report released on July 25, 2022. The zoonotic disease monkey-pox virus causes a feverish sickness in humans, with characteristic skin rashes and is similar to smallpox in structure, clinical presentation, and response to antiviral medicine. This review offers important insights on the evolution of the monkeypox virus and its different modes of transmission. It also discusses epidemiology, clinical findings, management, challenges, and current strategies for the disease, as well as the implications of the current epidemic on public health. Comprehensive research on the pathophysiology and management of monkeypox is still lacking. In order to solve this problem, we reviewed the pathology and virology of monkeypox infection and provided an overview of the most recent developments in anti-monkeypox medications.

Understanding the resurgence of mpox: key drivers and lessons from recent outbreaks in Africa

Mpox has re-emerged as a significant public health threat, particularly in Africa. This study explores the key drivers behind the recent resurgence, focusing on epidemiological trends, transmission dynamics, and lessons learned from recent outbreaks. The research involved a comprehensive review of recent mpox outbreaks, analyzing factors, such as socio-economic conditions, environmental influences, and genetic evolution. Findings indicate that the resurgence is linked to the cessation of smallpox vaccination, increased human-wildlife interactions, and rapid urbanization in endemic regions. The virus, which was previously confined to rural areas, has now spread to urban populations, and crossed national borders, driven by high population mobility and socio-economic instability. A notable shift in transmission dynamics has been observed, with increased human-to-human transmission, particularly among men who have sex with men (MSM), contributing to more severe and widespread outbreaks. The study highlights the urgent need to strengthen health systems in Africa, particularly in the areas of diagnostics, surveillance, and public health preparedness. Challenges such as inadequate laboratory infrastructure and delayed response mechanisms have exposed vulnerabilities in current public health frameworks. To prevent future outbreaks, targeted strategies must be implemented, including enhanced community engagement, improved access to vaccines and treatments, and timely, accurate reporting of cases. Coordinated global action is essential to prevent mpox from becoming a more persistent and widespread public health threat. This research discusses the importance of proactive measures and international cooperation in addressing the ongoing threat posed by mpox, particularly in regions with limited healthcare resources.

Monkeypox Virus and Pregnancy

Human monkeypox (Mpox) is a zoonotic disease caused by monkeypox virus (MPXV) present in western Africa and exported sporadically worldwide. MPXV causes illness in individuals and pregnant women which constitute a population at risk with obstetrical and fetal complications including miscarriage, stillbirth and premature delivery. There are accumulated data suggesting a vertical transmission of MPXV from mother to fetus. This review provides an overview of the literature on MPXV infection in pregnant women with a specific focus on vertical transmission.

Clinical characteristics of suspected cases of human mpox (monkeypox) in Katako-Kombe, Democratic Republic of the Congo 2023: challenges and key responses

OBJECTIVES

This study aimed to describe the clinical and epidemiologic characteristics of suspected cases of human mpox in one of the most affected health zones, Katako-Kombe, Sankuru Province, in the Democratic Republic of the Congo. Also, to identify key challenges to prevent and improve the health of the affected community.

METHODS

Between January 26, 2023 and November 30, 2023, the DRC reported its highest incidence of mpox cases,with a total of 12,569 suspected cases in 156 health zones from 22 of the 26 country's provinces. The Katako-Kombe Health Zone registered 369 suspected cases and 17 deaths, making it one of the hotspots of the outbreak.

RESULTS

Ten villages and centres were affected, with an attack rate (AT) of 2.15‰ and a case fatality rate (CFR) of 4.6%. Epi-curves showed an increase in clinical cases from January to May 2023, followed by a decrease until August 2023 and a resurgence of cases in September 2023, with a reproduction rate of 1.29. Furthermore, the occurrence of complications appeared to increase the CFR with 7 (14%), 11 (18.03%), and 9 (23.68%) for encephalitis, anemia, and pulmonary complications, respectively.

CONCLUSIONS

AT, CFR, and transmission rate appeared to be lower in the current epidemic than in previous outbreaks and in Clade I. Critically, delayed medical care increases the incidence of complications and CFR. Therefore, mpox requires early diagnosis and prompt public health response. Including the possibility of mpox in the differential diagnosis of patients presenting with a vesicular or pustular rash is suggested.

An overview of the progress made in research into the Mpox virus

Mpox is a zoonotic illness caused by the Mpox virus (MPXV), a member of the Orthopoxvirus family. Although a few cases have been reported outside Africa, it was originally regarded as an endemic disease limited to African countries. However, the Mpox outbreak of 2022 was remarkable in that the infection spread to more than 123 countries worldwide, causing thousands of infections and deaths. The ongoing Mpox outbreak has been declared as a public health emergency of international concern by the World Health Organization. For a better management and control of the epidemic, this review summarizes the research advances and important scientific findings on MPXV by reviewing the current literature on epidemiology, clinical characteristics, diagnostic methods, prevention and treatment measures, and animal models of MPXV. This review provides useful information to raise awareness about the transmission, symptoms, and protective measures of MPXV, serving as a theoretical guide for relevant institutions to control MPXV.

A review of epidemiology, diagnosis, and management of Mpox: The role of One Health

Human monkeypox (Mpox) is an emerging zoonotic disease. Its clinical features are similar to but less severe than those of smallpox. The etiology of this disease is the monkeypox virus. This virus is a double-stranded DNA virus that is classified into the genus Orthopoxvirus and the family Poxviridae. Human monkeypox was first identified in 1970 and mainly occurred in Central and Western Africa. In 2022, outbreaks of Mpox virus infection occurred in several non-endemic countries and caused a potential threat to humans. It is urgent to take immediate action to control and prevent the outbreak of the Mpox virus infection. This paper summarizes the current status of Mpox and generated strategies for managing the Mpox epidemic. Although progress in the diagnostic methods and treatment of Mpox produces better knowledge, we argue that the sensitive surveillance for animal and human Mpox virus infection and evidence-based response and management of Mpox outbreaks is critical. This study highlights the need for further research on preventive and control strategies for Mpox disease approached through the One Health concept.

Immunogenicity of monkeypox virus surface proteins and cross-reactive antibody responses in vaccinated and infected individuals: implications for vaccine and therapeutic development

BACKGROUND

The monkeypox virus (MPXV) has raised global health concerns due to its widespread transmission. This study evaluated the MPXV immunogenic antigens and the impact of vaccinia virus (VACV) vaccination and MPXV infection on cross-reactive antibody responses to conserved proteins from representative MPXV strains that reflected the evolutionary trajectory.

METHODS

Phylogenetic analyses were first conducted to reveal the evolutionary trajectory of MPXV from 1970 to 2024. A total of 84 serum samples were collected: 42 from VACV-vaccinated individuals, 12 from MPXV-infected participants in the early stage, 13 from the late stage, and 17 from naive individuals. Demographic data, MPXV and HIV status, as well as other clinical information were collected using standardized forms. Immunogenicity, cross-reactive antibody responses, and amino acid similarity to 15 MPXV surface proteins were assessed using enzyme-linked immunosorbent assays, VACV neutralization tests, and sequence alignment. Data analysis methods included analysis of variance, Mann-Whitney U test, binary logistic regression, Pearson correlation, and linear regression, with a significance threshold of P < 0.05.

RESULTS

The 186 complete genome sequences were classified into different clades and lineages, ranging from clade Ia to clade IIb C.1.1. Individuals infected with MPXV demonstrated strong antibody responses to antigens A35R, B6R, H3L, and E8L. VACV-vaccinated individuals exhibited broader cross-reactivity, particularly against A21L (P = 0.0003), A28L (P = 0.0028), A29L (P = 0.0324), G2R (P = 0.0003), and H2R (P = 0.0008), compared to MPXV-infected individuals. Pearson correlation analysis revealed significant associations (P = 0.0049) between antibody responses and the amino acid sequence similarity with other orthopoxviruses. Furthermore, MPXV-infected individuals exhibited greater neutralizing activity against VACV than those VACV-vaccinated individuals (P < 0.0001), while the vaccinated group retained cross-protective immunity even decades post-vaccination.

CONCLUSIONS

A35R, B6R, H3L, and E8L are the main immunogenic antigens of MPXV. VACV-vaccination triggers a cross-reactive antibody response to MPXV surface proteins. Our findings suggest the need for targeted vaccines and antibody treatments for MPXV, as well as the reintroduction of smallpox vaccinations with booster doses for high-risk groups.

Strong and early monkeypox virus-specific immunity associated with mild disease after intradermal clade-IIb-infection in CAST/EiJ-mice

Monkeypox virus (MPXV) is a zoonotic poxvirus long endemic in West and Central Africa. Outbreaks, first the global spread of clade II outside Africa in 2022, and since 2023 the accelerating spread of clade I in central Africa, point to MPXV adaptations that pose the risk of it becoming more transmissible in humans. Animal models mimicking the clinical disease outcome in humans are important to better understand pathogenesis, host tropism, and the contribution of genetic mutations. Here, we demonstrate that MPXV infection via tail scarification in CAST/EiJ mice is an appropriate animal model to mimic human mpox. In our study, disease outcome is milder in clade IIb than clade IIa-infected mice, which is associated with enhanced immunogenicity early during infection. This suggests that clade IIb more efficiently activates host immune responses, highlighting how this animal model could facilitate studying new MPXV variants to help develop efficient antivirals and preventive measures.

Fluorescent Clade IIb Lineage B.1 Mpox Viruses for Antiviral Screening

The ongoing global outbreak of mpox caused by clade IIb viruses has led to more than 100,000 confirmed cases around the world, highlighting the urgent need for antiviral research to combat current and future mpox outbreaks. Reporter viruses expressing fluorescent proteins to monitor viral replication and virus spreading in cell culture provide a powerful tool for antiviral drug screening. In this work, we engineered two recombinant mpox clade IIb viruses by inserting, under the control of the vaccinia early/late promoter 7.5, the coding sequence of two different fluorescent proteins (EGFP and TurboFP635) in a previously unreported location within the viral genome. These recombinant viruses replicate in BSC-1 cells at rates similar to those of the parental virus. We show how these reporter mpox viruses allow the discrimination of infected cells by cell flow cytometry and facilitate the quantification of viral spread in cell culture. Finally, we validated these reporter viruses with two previously known inhibitors of poxvirus replication, cytosine arabinoside (AraC) and bisbenzimide.

AEDV Expert Document on the Management of Ulcerative Venereal Infections

Currently, ulcerative sexually transmitted infections, including syphilis, herpes simplex virus (HSV), lymphogranuloma venereum (LGV), chancroid, donovanosis and, more recently, monkeypox (MPOX), represent a growing challenge for health care professionals. The incidence of syphilis and LGV has increased in recent years in Spain. Additionally, HSV, syphilis and chancroid can also increase the risk of HIV acquisition and transmission. The population groups most vulnerable to these infections are young people, men who have sex with men (MSM) and commercial sex workers. It is important to make a timely differential diagnosis since genital, anal, perianal, and oral ulcerative lesions may pose differential diagnosis with other infectious and non-infectious conditions such as candidiasis vulvovaginitis, traumatic lesions, carcinoma, aphthous ulcers, Behçet's disease, fixed drug eruption, or psoriasis. For this reason, the dermatologist plays a crucial role in the diagnosis and management of sexually transmitted infections. This chapter presents the main epidemiological, clinical and therapeutic features associated with these infections.

A label-free optical biosensor-based point-of-care test for the rapid detection of Monkeypox virus

Diagnostic approaches that combine the high sensitivity and specificity of laboratory-based digital detection with the ease of use and affordability of point-of-care (POC) technologies could revolutionize disease diagnostics. This is especially true in infectious disease diagnostics, where rapid and accurate pathogen detection is critical to curbing the spread of disease. We have pioneered an innovative label-free digital detection platform that utilizes Interferometric Reflectance Imaging Sensor (IRIS) technology. IRIS leverages light interference from an optically transparent thin film, eliminating the need for complex optical resonances to enhance the signal by harnessing light interference and the power of signal averaging in shot-noise-limited operation In our latest work, we have further improved our previous 'Single-Particle' IRIS (SP-IRIS) technology by allowing the construction of the optical signature of target nanoparticles (whole virus) from a single image. This new platform, 'Pixel-Diversity' IRIS (PD-IRIS), eliminated the need for z-scan acquisition, required in SP-IRIS, a time-consuming and expensive process, and made our technology more applicable to POC settings. Using PD-IRIS, we quantitatively detected the Monkeypox virus (MPXV), the etiological agent for Monkeypox (Mpox) infection. MPXV was captured by anti-A29 monoclonal antibody (mAb 69-126-3) on Protein G spots on the sensor chips and were detected at a limit-of-detection (LOD) - of 200 PFU/mL (∼3.3 aM). PD-IRIS was superior to the laboratory-based ELISA (LOD - 1800 PFU/mL) used as a comparator. The specificity of PD-IRIS in MPXV detection was demonstrated using Herpes simplex virus, type 1 (HSV-1), and Cowpox virus (CPXV). This work establishes the effectiveness of PD-IRIS and opens possibilities for its advancement in clinical diagnostics of Mpox at POC. Moreover, PD-IRIS is a modular technology that can be adapted for the multiplex detection of pathogens for which high-affinity ligands are available that can bind their surface antigens to capture them on the sensor surface.

Suspected and confirmed mpox cases in DR Congo: a retrospective analysis of national epidemiological and laboratory surveillance data, 2010-23

BACKGROUND

DR Congo has the highest global burden of mpox, a disease caused by infection with the monkeypox virus. The incidence has risen since 1980, but recent analyses of epidemiological trends are lacking. We aimed to describe trends in suspected and confirmed mpox cases in DR Congo using epidemiological and laboratory mpox surveillance data collected from 2010 to 2023, and provide insights that can better inform the targeting and monitoring of control strategies.

METHODS

We analysed aggregated national epidemiological surveillance data and individual-level laboratory data from 2010 to 2023. We calculated incidence based on suspected cases, case-fatality ratios, and percentage of laboratory-confirmed cases and assessed geospatial trends. Demographic and seasonal trends were investigated using generalised additive mixed models.

FINDINGS

Between Jan 1, 2010, and Dec 31, 2023, a total of 60 967 suspected cases and 1798 suspected deaths from mpox were reported in DR Congo (case-fatality ratio 2·9%). The number of reporting provinces increased from 18 of 26 provinces in 2010 to 24 of 26 provinces in 2023. The annual incidence increased from 2·97 per 100 000 in 2010 to 11·46 per 100 000 in 2023. The highest incidence (46·38 per 100 000) and case-fatality ratio (6·0%) were observed in children younger than 5 years. Incidence was higher in rural compared with urban areas. PCR testing was performed for 7438 suspected cases (12·2%), with 4248 (57·1%) of 7438 samples testing positive. Median age of confirmed cases (13·0 years [IQR 6·0-25·0]) remained stable, although the 95th percentile of age increased over time.

INTERPRETATION

The incidence and geographical distribution of suspected mpox cases have increased substantially since 2010. Improvements in surveillance and decentralised testing are essential to monitor mpox trends and direct interventions effectively, to address the public health emergency declarations issued in August, 2024.

FUNDING

Belgian Directorate-General Development Cooperation and Humanitarian Aid; European and Developing Countries Clinical Trials Partnership; Research Foundation-Flanders; European Civil Protection and Humanitarian Aid Operations; Department of Economy, Science, and Innovation of the Flemish Government; Canadian Institutes of Health Research; and the International Development Research Centre.

[Translated article] AEDV Expert Document on the Management of Ulcerative Venereal Infections

Currently, ulcerative sexually transmitted infections, including syphilis, herpes simplex virus (HSV), lymphogranuloma venereum (LGV), chancroid, donovanosis and, more recently, monkeypox (MPOX), represent a growing challenge for health care professionals. The incidence of syphilis and LGV has increased in recent years in Spain. Additionally, HSV, syphilis and chancroid can also increase the risk of HIV acquisition and transmission. The population groups most vulnerable to these infections are young people, men who have sex with men (MSM) and commercial sex workers. It is important to make a timely differential diagnosis since genital, anal, perianal, and oral ulcerative lesions may pose differential diagnosis with other infectious and non-infectious conditions such as candidiasis vulvovaginitis, traumatic lesions, carcinoma, aphthous ulcers, Behçet's disease, fixed drug eruption, or psoriasis. For this reason, the dermatologist plays a crucial role in the diagnosis and management of sexually transmitted infections. This chapter presents the main epidemiological, clinical and therapeutic features associated with these infections.

Sinefungin analogs targeting VP39 methyltransferase as potential anti-monkeypox therapeutics: a multi-step computational approach

The increasing spread of the Monkeypox virus (MPXV) presents a significant public health challenge, emphasising the urgent requirement for effective treatments. Our study focuses on the VP39 Methyltransferase enzyme of MPXV as a critical target for therapy. By utilising virtual screening, we investigated natural compounds with structural similarities to sinefungin, a broad-acting MTase inhibitor. From an initial set of 177 compounds, we identified three promising compounds-CNP0346326, CNP0343532, and CNP008361, whose binding scores were notably close to that of sinefungin. These candidates bonded strongly to the VP39 enzyme, hinting at a notable potential to impede the virus. Our rigorous computational assays, including re-docking, extended molecular dynamics simulations, and energetics analyses, validate the robustness of these interactions. The data paint a promising picture of these natural compounds as front-runners in the ongoing race to develop MPXV therapeutics and set the stage for subsequent empirical trials to refine these discoveries into actionable medical interventions.

Mpox Virus as a Global Public Health Emergency: A Scoping Review

The monkeypox (Mpox) virus has emerged as a global public health emergency of international concern recently. The virus that was endemic in West and Central Africa has now been reported with chains of global transmission to several countries. A scoping review was carried out from the relevant literature available from PubMed, Scopus and Web of Science. This comprehensive analysis describes the virus epidemiology, pathogenesis, clinical manifestations, complications including secondary bacterial infections, diagnosis, treatment and vaccination. The article underscores the significance of key viral and immune mediators of infection and discusses updated recommendations on therapeutic strategies and vaccination.

Complete Genome Sequence Analysis of the First Imported Mpox Virus Clade Ib Variant in China

Mpox, a zoonotic disease caused by the mpox virus (MPXV), has seen a significant shift in its epidemiological status since 2022, evolving from an initial local outbreak to a global epidemic. This recent outbreak of MPXV mainly emerged in several European and American countries and subsequently spread to over 100 countries and regions worldwide. The rapid evolution of MPXV, coupled with increased international interactions, has led to a gradual rise in mpox cases in certain regions of Asia, mostly involving MPXV clade II and its branch strains. In contrast, the more pathogenic and clinically severe MPXV clade Ib has been relatively rare, with no reports in China to date. Here, we analyzed the whole gene sequence of imported MPXV clade Ib variant from the first infection case detected in China. Through whole genome sequencing, we successfully obtained a full-length MPXV genome of 195,405 base pairs (bp). Phylogenetic analysis revealed that the genetic sequence of the MPXV in this case was predominantly clustered with MPXV clade Ib sequences previously reported from multiple African and European countries. Compared with the MPXV clade Ib reference strain DQ011155.1, there are 127 nucleotide alterations and 57 amino acid mutations in the MPXV genome of this case. Given that the MPXV clade Ib has started to appear in China, we must pay more attention to the prevention of and control measures for the spread of mpox.

Monkeypox: a re-emergent virus with global health implications - a comprehensive review

Monkeypox virus (MPXV) is an enclosed, double-stranded DNA virus from the Orthopoxvirus genus, which also contains variola, vaccinia, and cowpox. MPXV, which was once confined to West and Central Africa, has recently had a rebound, spreading beyond its original range since 2017. The virus is distinguished by its unique morphology, which includes an oval or brick-shaped structure and a complex lipid and protein makeup. The current multi-country outbreak designated a public health emergency in 2022, has highlighted MPXV's shifting epidemiology and ability to spread rapidly over the globe. 'No one is safe until everyone is safe' is a slogan we often heard during the COVID-19 pandemic, which is now also required for the growing global and regional mpox outbreaks. The epidemic is divided into two clades: Clade I and Clade II, which have distinct pathogenic characteristics. Diagnostic approaches have developed with advances in molecular techniques, yet problems persist in resource-constrained situations. This overview summarizes the virus's history, epidemiology, morphology, and clinical characteristics, offering insights into its recent comeback and current global response efforts.

Development and Validation of LAMP Assays for Distinguishing MPXV Clades with Fluorescent and Colorimetric Readouts

Human monkeypox (Mpox) is a zoonotic disease caused by the Monkeypox virus (MPXV). As of 14 August 2024, the World Health Organization (WHO) has declared it a global health emergency. For Mpox, this was the second public health emergency of global significance in the past two years. MPXV belongs to the Poxviridae family and is phylogenetically and epidemically divided into two clades: the Congo Basin (Clade-I) and the West African (Clade-II) clades. Clade-I has been associated with more severe disease progression and higher mortality compared to Clade-II, and thus the differentiation between clades can play an important role in predicting disease prognosis. The LAMP technique has the advantages of not requiring thermal cycling and achieving higher amplification in a shorter time compared to qPCR. Different types of LAMP assays were developed in this study to benefit from these advantages. We report the development of LAMP-1 and LAMP-2 assays using the LAMP method to detect MPXV Clade-I and Clade-II, respectively. The LAMP-1 assay includes both fluorescence and visible colorimetric readout tests developed with sensitivities of 103 and 107 copies, respectively. For the LAMP-2 assay, a probe-based test utilizing the Novel R-Duplex DARQ probe was developed, offering fluorescence detection at a sensitivity of 103 copies. As a result, we successfully developed three highly specific molecular diagnostic tests that distinctly differentiate between MPXV clades, delivering essential tools for the precise diagnosis and effective control of Mpox.

Transcriptomic and Proteomic Analysis of Monkeypox Virus A5L-Expressing HEK293T Cells

Monkeypox (MPOX) is a zoonotic viral disease caused by the Monkeypox virus (MPXV), which has become the most significant public health threat within the Orthopoxvirus genus since the eradication of the Variola virus (VARV). Despite the extensive attention MPXV has garnered, little is known about its clinical manifestations in humans. In this study, a high-throughput RNA sequencing (RNA-seq) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach was employed to investigate the transcriptional and metabolic responses of HEK293T cells to the MPXV A5L protein. RNA-seq analysis identified a total of 1473 differentially expressed genes (DEGs), comprising 911 upregulated and 562 downregulated genes. Additionally, LC-MS/MS analysis revealed 185 cellular proteins with significantly altered abundance ratios that interact with the A5L protein. Here, we perform Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of the transcriptome and proteome signatures of MPXV A5L-expressing HEK293T cells to gain insights into the virus proteins-host interplay. Transcriptomic analysis revealed that transfection of the MPXV A5L protein modulated genes primarily associated with the cell cycle, ribosome, and DNA replication. Proteomic analysis indicated that this protein predominantly interacted with host ribosomal proteins and cytoskeletal proteins. The combination of transcriptomic and proteomic analysis offers new perspectives for understanding the interaction between pathogens and hosts. Our research emphasizes the significant role of MPXV A5L in facilitating viral internalization and assembly, as well as its impact on the host's translation system.

Concurrent outbreaks of mpox in Africa-an update

In this Review, we examine the concurrent outbreaks of mpox in Africa, focusing on clade 1a, the newly emerged clade 1b, and clade 2b lineage A, and how they differ from the 2022 global outbreak caused by clade 2b lineage B.1. Historically, clades 1a and 2a have caused sporadic, small outbreaks in central and west Africa, respectively, primarily through zoonotic transmission. Clade 2b first caused an outbreak in Nigeria in 2017, and later spread globally via sexual contact in 2022. In August, 2024, WHO declared a global health emergency due to the newly identified clade 1b outbreak in eastern Democratic Republic of the Congo. This outbreak has now expanded to several other countries and is spreading through direct and sexual contact in urban centres and refugee camps. Clades, route of exposure, infectious dose, and host immune response are the main factors influencing clinical presentation of mpox. For clades 1a and 2a, zoonotic transmission plays an important role, whereas for clades 1b and 2b, the spread occurs through sustained human-to-human transmission without zoonotic exposure. For both clades 1a and 2a, lesions have a generalised centrifugal distribution, whereas for clade 2b they are mainly localised to the anogenital area. For clade 1b, data are still emerging, but current cases show a mix of localised lesions and centrifugal distribution. The severity of the disease is higher for clade 1a (case fatality rate up to 12%) compared with other clades (case fatality rates 0-3·6%). Diagnostic challenges include false negative results for clade 1b with existing PCR assays and poor testing access in remote areas. Tecovirimat, the primary antiviral during the 2022 outbreak, has shown reduced effectiveness against clade 1a in preliminary study results, whereas its efficacy against other clades is still under investigation. The modified vaccinia Ankara-Bavarian Nordic vaccine has been shown to be up to 90% effective against clade 2b after two doses and is safe for children, although its effectiveness drops to 20% when used as post-exposure prophylaxis. Given the evolving nature of the monkeypox virus, ongoing research and strong public health responses are key to managing potential future outbreaks.

Monkeypox Global Research: A Comprehensive Analysis from Emergence to Present (1961-2023) for innovative prevention and control approaches

The current study aims to identify research hotspots and trends in Monkeypox (MPX). A total of 2655 MPX-related articles published from 1961 to 2023 were extracted from the Scopus database. Data were analyzed using Scopus Analytics, Microsoft Excel, Bibliometrix, and VOSviewer. The number of MPX papers has been increasing annually, particularly since the most recent outbreak. The United States and India have been productive in this area. The most cited and productive scholar in the field is Inger K. Damon. The MPX research theme map shows clusters with various centralities and densities, focusing on deep learning, molecular docking, and orthopoxviruses. Over the last decade, key terms include "transmission," "pandemic," "deep learning," "docking," "Democratic Republic of Congo," "Ebola," "virulence," "modified vaccinia Ankara," and "orthopoxvirus." Researchers can utilize existing findings to steer future research on this illness, prepare for potential pandemics, and address bioterrorist threats.

Poxvirus Epidemiology

Illnesses caused by poxviruses have plagued humanity for millennia. The most notable are caused by viruses comprising the orthopoxvirus genus. Smallpox (caused by Variola virus) became the first eradicated disease in 1980. Devotion to smallpox eradication required significant orthopoxvirus research and discovery including vaccine and medical countermeasure development. Here we describe historical and current poxvirus epidemiology, with particular emphasis on orthopoxviruses including Monkeypox virus and Vaccinia virus.

Mpox Specimen Collection, Storage, Preparation, and Laboratory Diagnostics by PCR

During the 2022 and ongoing mpox outbreak, PCR diagnostics were already within the Laboratory Response Network (LRN) laboratories and additionally rapidly deployed to detect monkeypox (mpox) virus in patients and aid in accurate diagnosis. This accuracy is dependent on proper collection, shipment, and adherence to PCR procedure. This book chapter discusses effective collection, storage, and transportation for a real-time PCR to detect monkeypox virus nucleic acid.

Optimizing Microneutralization and IFN-γ ELISPOT Assays to Evaluate Mpox Immunity

BACKGROUND

Available assays to measure pox virus neutralizing antibody titers are laborious and take up to 5 days. In addition, assays to measure T cell responses require the use of specific antigens, which may not be the same for all pox viruses. This study reports the development of robust assays for the measurement of mpox-specific neutralizing antibodies and IFN-γ-producing T-cell responses.

METHODS

Fourteen samples from 7 volunteers who received Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) were used. The focused reduction neutralization test (FRNT) was performed using the mpox-specific A29 monoclonal antibody. Optimization and further development of FRNT were conducted using the plaque reduction neutralization test (PRNT) as the gold standard. The mpox-specific IFN-γ ELISPOT assay was optimized using different mpox antigen preparations. Results with pre-vaccination samples were compared with post-vaccination samples using the Wilcoxon matched-pairs test.

RESULTS

Pre-vaccination and post-vaccination sera (n = 7) had FRNT50 (i.e., titers that inhibited at least 50% of the virus) of 109.1 ± 161.8 and 303.7 ± 402.8 (mean ± SD), respectively. Regression analysis of fold changes in FRNT50 and PRNT50 showed that the two assays closely agree (n = 25 tests on paired samples, R2 of 0.787). Using UV-inactivated mpox as an antigen, the number of IFN-γ spot-forming T cells (SFC) in pre-vaccination samples (16.13 ± 15.86, mean ± SD) was significantly lower than SFC in post-vaccination samples (172.9 ± 313.3, mean ± SD) with p = 0.0078.

CONCLUSIONS

Our newly developed microneutralization test has a good correlation with PRNT. UV-inactivated mpox is an appropriate antigen for the ELISPOT assay that measures mpox cross-reactive T cells. These assays will be useful in future mpox vaccine studies.

Comprehensive Insights into Monkeypox (mpox): Recent Advances in Epidemiology, Diagnostic Approaches and Therapeutic Strategies

Monkeypox (mpox) is a viral infection closely related to smallpox, manifesting as a milder febrile rash in affected individuals. Over the past two decades, the incidence of mpox has surged, possibly linked to a declining immunity against the smallpox vaccine worldwide. Recent outbreaks of mpox in multiple countries have sparked concerns regarding altered transmission patterns and the potential for a global menace. In this article, we present a multidimensional review encompassing the latest scientific discoveries, illuminating the intricate structure of the human mpox virus. Key findings include advancements in understanding the virus's molecular mechanisms, which highlight its genetic adaptability and potential for zoonotic spillover. Diagnostic innovations, such as improved molecular assays, have enhanced detection accuracy, while novel therapeutic strategies, including antiviral drugs and vaccines, show promise in mitigating outbreaks. Our conclusions emphasize the importance of robust surveillance systems, vaccination programs, and rapid response strategies to curb mpox's spread. Future recommendations include strengthening global collaboration for zoonotic disease surveillance, advancing the research on host-pathogen interactions, and developing next-generation therapeutics to address this emerging public health threat effectively.

Exploring the genomic basis of Mpox virus-host transmission and pathogenesis

Mpox disease, caused by the monkeypox virus (MPXV), was recently classified as a public health emergency of international concern due to its high lethality and pandemic potential. MPXV is a zoonotic disease that emerged and is primarily spread by small rodents. Historically, it was considered mainly zoonotic and not likely to sustain human-to-human transmission. However, the worldwide outbreak of Clade IIb MPXV from 2020 to 2022 and ongoing Clade I MPXV epidemics in the Democratic Republic of the Congo and surrounding areas are a warning that human-adapted MPXVs will continually arise. Understanding the viral genetic determinants of host range, pathogenesis, and immune evasion is imperative for developing control strategies and predicting the future of Mpox. Here, we delve into the MPXV genome to detail genes involved in host immune evasion strategies for this zoonotic rodent-borne and human-circulating virus. We compare MPXV gene content to related Orthopoxviruses, which have narrow host ranges, to identify potential genes involved in species-specific pathogenesis and host tropism. In addition, we cover the key virulence factor differences that distinguish the MPXV clade lineages. Finally, we dissect how genomic reduction of Orthopoxviruses, through various molecular mechanisms, is contributing to the generation of novel MPXV lineages with increased human adaptation. This review aims to highlight gene content that defines the MPXV species, MPXV clades, and novel MPXV lineages that have culminated in this virus being elevated to a public health emergency of national concern.

Therapeutic agents for the treatment of human mpox

PURPOSE OF REVIEW

The aim of this study was to summarize the current knowledge of therapeutic options for mpox (formerly known as monkeypox) in the context of recent outbreaks and the ongoing evolution of the virus.

RECENT FINDINGS

Multiple therapeutic agents, including tecovirimat, cidofovir, brincidofovir, and vaccinia immune globulin, have been used during the multicountry outbreak of mpox caused by Clade 2b monkeypox virus that began in 2022. Tecovirimat has been most extensively used, based on efficacy against mpox lethal challenge in animal models, and human safety data. Real-world observational evidence has further supported safety with minimal adverse events in large cohorts and mixed reports of reductions in time to lesion resolution. Several prospective randomized controlled trials using tecovirimat are underway with headline results from a study in the Democratic Republic of the Congo showing no difference in lesion resolution compared to placebo. Other studies including in outpatient settings are underway in Europe and the Americas. Cidofovir and brincidofovir, limited by adverse event profiles, have been less extensively studied. Vaccinia immune globulin has been used predominantly in salvage therapy for severe mpox, with no large observational series available.

SUMMARY

The 2022 multicountry outbreak of mpox marked a public health emergency. Agents approved for smallpox management were widely used for mpox, supported by animal and in-vitro evidence, and human safety data. The large number of human cases has allowed retrospective observational study of these agents and facilitated recruitment in prospective trials. The ongoing evolution of the virus may pose challenges for therapeutic interventions, necessitating rigorous randomized controlled trials to guide clinical use.

Mpox virus Clade IIb infected Cynomolgus macaques via mimic natural infection routes closely resembled human mpox infection

Generating an infectious non-human primate (NHP) model using a prevalent monkeypox virus (MPXV) strain has emerged as a crucial strategy for assessing the efficacy of vaccines and antiviral drugs against human MPXV infection. Here, we established an animal model by infecting cynomolgus macaques with the prevalent MPXV strain, WIBP-MPXV-001, and simulating its natural routes of infection. A comprehensive analysis and evaluation were conducted on three animals, including monitoring clinical symptoms, collecting hematology data, measuring viral loads, evaluating cellular and humoral immune responses, and examining histopathology. Our findings revealed that initial skin lesions appeared at the inoculation sites and subsequently spread to the limbs and back, and all infected animals exhibited bilateral inguinal lymphadenopathy, eventually leading to a self-limiting disease course. Viral DNA was detected in post-infection blood, nasal, throat, rectal and blister fluid swabs. These observations indicate that the NHP model accurately reflects critical clinical features observed in human MPXV infection. Notably, the animals displayed clinical symptoms and disease progression similar to those of humans, rather than a lethal outcome as observed in previous studies. Historically, MPXV was utilized as a surrogate model for smallpox. However, our study contributes to a better understanding of the dynamics of current MPXV infections while providing a potential infectious NHP model for further evaluation of vaccines and antiviral drugs against mpox infection. Furthermore, the challenge model closely mimics the primary natural routes of transmission for human MPXV infections. This approach enhances our understanding of the precise mechanisms underlying the interhuman transmission of MPXV.

Experimental inoculation of pigs with monkeypox virus results in productive infection and transmission to sentinels

Monkeypox virus (MPXV) is a re-emerging zoonotic poxvirus responsible for producing skin lesions in humans. Endemic in sub-Saharan Africa, the 2022 outbreak with a clade IIb strain has resulted in ongoing sustained transmission of the virus worldwide. MPXV has a relatively wide host range, with infections reported in rodent and non-human primate species. However, the susceptibility of many domestic livestock species remains unknown. Here, we report on a susceptibility/transmission study in domestic pigs that were experimentally inoculated with a 2022 MPXV clade IIb isolate or served as sentinel contact control animals. Several principal-infected and sentinel contact control pigs developed minor lesions near the lips and nose starting at 12 through 18 days post-challenge (DPC). No virus was isolated and no viral DNA was detected from the lesions; however, MPXV antigen was detected by IHC in tissue from a pustule of a principal infected pig. Viral DNA and infectious virus were detected in nasal and oral swabs up to 14 DPC, with peak titers observed at 7 DPC. Viral DNA was also detected in nasal tissues or skin collected from two principal-infected animals at 7 DPC post-mortem. Furthermore, all principal-infected and sentinel control animals enrolled in the study seroconverted. In conclusion, we provide the first evidence that domestic pigs are susceptible to experimental MPXV infection and can transmit the virus to contact animals.

Monkeypox 2024 outbreak: Fifty essential questions and answers

As the world still vividly recalls the previous monkeypox (mpox) outbreak that impacted over 120 countries worldwide with more than 99,000 cases in 2022, we are now facing a second wave of infections from the monkeypox virus (MPXV), characterized by an exponential increase in cases. The current 2024 outbreak has already recorded more than 20,000 cases in Africa, marking a dramatic escalation compared to previous outbreaks. The predominance of the newly identified clade Ib variant, first detected in the Democratic Republic of the Congo (DRC) and now identified across multiple African nations and beyond, underscores its enhanced transmissibility and potential for international spread, evidenced by cases in Sweden and Thailand. The World Health Organization (WHO) declared on August 14, 2024, the current mpox outbreak a Public Health Emergency of International Concern (PHEIC), calling for heightened global public health measures. The ongoing pattern of unusual, frequent, and extensive outbreaks of mpox with potential global implications poses significant questions. This review addresses, in the format of 50 questions and answers, the 2024 mpox outbreak, detailing its characteristics, epidemiological data, and impact compared to previous outbreaks. It comprehensively explores critical questions related to MPXV virological characteristics, immunological response, clinical manifestations, epidemiology, diagnostics, and available treatments. The review also documents the significant and evolving challenges posed by the current mpox outbreak, highlighting its scale, spread, and public health response.

Evaluation of analytical performance of the STANDARDTM M10 MPX/OPX assay for the simultaneous DNA detection and clade attribution of Monkeypox virus

Monkeypox virus (MPXV) infection confirmation needs reliable polymerase chain reaction (PCR) assays; in addition, viral clade attribution is a key factor in containment measures, considering a more severe syndrome in clade I and the possibility of simultaneous circulation. This study evaluates the performance of all-in-one STANDARD M10 MPX/OPX (SD BIOSENSOR, South Korea - M10). Frozen samples from 205 subjects were selected and stratified according to routine test results (RealStar® Orthopoxvirus PCR Kit 1.0, Altona DIAGNOTICS, Germany - RS; RS-1): in detail, 100 negative skin lesions (SL) and 200 positive samples at the variable stage of infection were analysed. Positive samples were retested with RS (RS-2). Positive and Negative Percent Agreements (PPA, NPA) were calculated. The median (IQR) Ct values of RS and M10 (OPXV target) assays were highly similar. The PPA of M10 compared to RS-1 was 89.5% considering system interpretation, and 96.0% when the operator classified results as positive if any target was detected; NPA was 100%. Comparing the RS-2 run and M10, an overall concordance of 95.3% between assays was found; however, considering operator interpretation, M10 returned more positive results than RS-2. The occurrence of False-Negative results was likely associated with the influence of thawing on low viral concentration; no False-Positive tests were observed. All samples collected at the time of Mpox diagnosis were positive and M10 correctly attributed the clade (West-Africa/II). The M10 MPX/OPX assay demonstrated high reliability in confirming MPXV infection and clade attribution.

Global perspectives on smallpox vaccine against monkeypox: a comprehensive meta-analysis and systematic review of effectiveness, protection, safety and cross-immunogenicity

A large outbreak of monkeypox occurred in 2022, and most people lack immunity to orthopoxvirus. Smallpox vaccination is essential for preventing further smallpox outbreaks. This study evaluated the effectiveness, protection, safety, and cross-immunogenicity of smallpox vaccine in preventing monkeypox infection. PubMed, Embase, Scopus, and Web of Science were searched from database inception to 10 March 2024. We included studies involving "monkeypox virus" and "vaccinations", and excluded reviews, animal studies, and articles with missing or duplicate data. A total of 37 studies with 57,693 participants were included in the final analysis. The effectiveness data showed that monkeypox infection rates were lower in the smallpox-vaccinated group than in the unvaccinated group (risk ratio [RR]: 0.46; 95% confidence interval [CI]: 0.31-0.68). The protection data showed that smallpox vaccination effectively reduced the risk of severe monkeypox infection (RR: 0.61; 95% CI: 0.42-0.87). Third-generation vaccines showed greater efficacy (RR: 0.36, 95% CI: 0.22-0.56) than first-generation vaccines. The number of doses of smallpox vaccine has no significant effect on monkeypox. Safety data showed that adverse reactions after smallpox vaccination were mainly mild and included local erythema, swelling, induration, itching, and pain. Meanwhile, we found that smallpox vaccination could induce the production of neutralizing antibodies against monkeypox. Our findings offer compelling evidence supporting the clinical application of the smallpox vaccine for preventing monkeypox and advocate that high-risk groups should be prioritized for receiving one dose of the smallpox vaccine if the vaccine stockpile is low.

Mpox Resurgence: A Multifaceted Analysis for Global Preparedness

This study provides an in-depth analysis of mpox, encompassing its history, characteristics, epidemiology, diagnostics, treatment options, and the ongoing evolution of the virus and its transmission dynamics. Mpox, though once successfully eradicated, has re-emerged with new modes of transmission and a broader host range. Genomic analyses have revealed the virus's adaptability, posing challenges for diagnostics and vaccine efficacy. The epidemiology has shifted from sporadic zoonotic transmission in rural Africa to a significant presence in urban areas, particularly impacting high-risk populations. Advancements in diagnostics and therapeutics offer hope, but challenges persist. This work underscores the critical need for enhanced surveillance, vaccination strategies, and continued research to bolster global health systems and preparedness for future outbreaks.

Comparative Analysis of 2022 Outbreak MPXV and Previous Clade II MPXV

The 2022-2024 outbreak of MPOX is an important worldwide public health issue that has triggered significant concerns in the scientific community. MPOX is caused by monkeypox virus (MPXV) belonging to the Poxviridae family. The study of MPXV presents a multifaceted challenge due to the diverse viral formThis study was supported by ISIDORe consortium and Agencia Estatal de Investigación.s produced by this pathogen. Notably the intracellular mature viruses (MVs) primarily contribute to localized lesions and host-to-host transmission, while the extracellular enveloped viruses (EVs) are associated with systemic infection. Clinically, MPOX manifests as a vesiculopustular rash that initially emerges on the face and trunk, subsequently spreading throughout the body, with heightened severity observed in immunocompromised individuals. Results obtained in this manuscript indicate that the 2022 outbreak MPXV has a significantly slower viral cycle compared with previous Clade II strains, with WRAIR 7-61 being more intermediate and USA 2003 producing highest viral titers. Additionally, proteomic and phospho-proteomic analysis displays differences in protein expression between these three strains. These findings highlight key differences between the current Lineage B.1 MPXV and previous strains. Further studies will be undertaken to demonstrate if these differences are important for the apparent increased human-to-human transmission mechanisms observed in the Clade IIb MPXV outbreak.