Proteomic basis of the antibody response to monkeypox virus infection examined in cynomolgus macaques and a comparison to human smallpox vaccination

Monkeypox virus genomic accordion strategies

The 2023 monkeypox (mpox) epidemic was caused by a subclade IIb descendant of a monkeypox virus (MPXV) lineage traced back to Nigeria in 1971. Person-to-person transmission appears higher than for clade I or subclade IIa MPXV, possibly caused by genomic changes in subclade IIb MPXV. Key genomic changes could occur in the genome's low-complexity regions (LCRs), which are challenging to sequence and are often dismissed as uninformative. Here, using a combination of highly sensitive techniques, we determine a high-quality MPXV genome sequence of a representative of the current epidemic with LCRs resolved at unprecedented accuracy. This reveals significant variation in short tandem repeats within LCRs. We demonstrate that LCR entropy in the MPXV genome is significantly higher than that of single-nucleotide polymorphisms (SNPs) and that LCRs are not randomly distributed. In silico analyses indicate that expression, translation, stability, or function of MPXV orthologous poxvirus genes (OPGs), including OPG153, OPG204, and OPG208, could be affected in a manner consistent with the established "genomic accordion" evolutionary strategies of orthopoxviruses. We posit that genomic studies focusing on phenotypic MPXV differences should consider LCR variability.

Monkeypox: Can we count on the current smallpox immunization?

Two vaccines ACAM 2000 and JYNNEOS have obtained approval from the Food and Drug Administration as preventive measures against monkeypox, contributing significantly to the management of the monkeypox epidemic. Nonetheless, research has demonstrated that smallpox vaccination offers approximately 88.8% protection against monkeypox, while immunization with these vaccines generates relatively low levels of neutralizing antibodies. In this work, we performed a comprehensive comparison of antigens between the 2022-2023 monkeypox strains and the smallpox vaccine strains. Our analysis has revealed considerable amino acid changes in all 27 antigens, including core and envelope proteins. Amino acid substitutions within B cell epitopes were observed in 26 of these antigens, with at least half of the antigen substitutions occurring within B cell epitopes in 20 out of the 26 antigens analyzed. These findings may raise potential concerns regarding the efficacy of these vaccines.

Role of the Laboratory in the Diagnosis of Poxvirus Infections

Although WHO-led global efforts led to eradication of smallpox over four decades ago, other poxviruses, especially monkeypox, have re-emerged to occupy the ecological niche vacated by smallpox. Many of these viruses produce similar lesions thus mandating a prompt laboratory confirmation. There has been considerable evolution in the techniques available to diagnose these infections and differentiate between them. With the 2022 multi-country outbreak of monkeypox, significant efforts were made to apprise the laboratory diagnosis of the virus and numerous real-time-PCR-based assays were made commercially available. This chapter discusses the sample collection and biosafety aspects along with the repertoire of diagnostic modalities, both traditional and emerging, for poxviruses which a special focus on monkeypox. The advantages and disadvantages of each technique have been illustrated. We have also reflected upon the newer advances and the existing lacunae.

Evaluation and comparison of immune responses induced by two Mpox mRNA vaccine candidates in mice

The epidemic of Mpox virus (MPXV) from May 2022 was once declared as a Public Health Emergency of International Concern by the World Health Organization. Vaccines play an important role in prevention of infectious diseases, and mRNA vaccine technology was proved to be a safe and effective platform with successful application in defense of coronavirus disease 2019. In this study, based on A29L, M1R, A35R, and B6R of MPXV, we developed two MPXV mRNA vaccine candidates, designated as MPXfus and MPXmix. The MPXfus was one-component, in which these four antigen proteins were linked in tandem by flexible linker and encoded by an individual mRNA as a fusion protein. The MPXmix was multicomponent containing four mRNA, and each mRNA encoded one antigen protein respectively. Mice were immunized with equal quality of MPXfus or MPXmix, delivered by lipid nanoparticles for evaluation and comparison of the immune responses induced by these two MPXV vaccine candidates. Results of immune response analyses indicated that both MPXfus and MPXmix could elicit high-level of antigen-specific antibodies and robust cellular immune response in mice. Moreover, results of virus neutralization assays suggested that sera from MPXfus- or MPXmix-immunized mice possessed high neutralizing activities against vaccinia virus. In addition, titers of antigen-specific antibody, levels of cellular immune response, and activities of neutralizing antibody against vaccinia virus induced by MPXfus and MPXmix presented no significant difference. In summary, this study provides valuable insights for further clinical development of one-component and multicomponent mRNA vaccine candidates for the prevention of MPXV and other orthomyxoviruses.

Monkeypox virus-infected individuals mount comparable humoral immune responses as Smallpox-vaccinated individuals

In early 2022, a cluster of monkeypox virus (MPXV) infection (mpox) cases were identified within the UK with no prior travel history to MPXV-endemic regions. Subsequently, case numbers exceeding 80,000 were reported worldwide, primarily affecting gay, bisexual, and other men who have sex with men (GBMSM). Public health agencies worldwide have offered the IMVANEX Smallpox vaccination to these individuals at high-risk to provide protection and limit the spread of MPXV. We have developed a comprehensive array of ELISAs to study poxvirus-induced antibodies, utilising 24 MPXV and 3 Vaccinia virus (VACV) recombinant antigens. Panels of serum samples from individuals with differing Smallpox-vaccine doses and those with prior MPXV infection were tested on these assays, where we observed that one dose of Smallpox vaccination induces a low number of antibodies to a limited number of MPXV antigens but increasing with further vaccination doses. MPXV infection induced similar antibody responses to diverse poxvirus antigens observed in Smallpox-vaccinated individuals. We identify MPXV A27 as a serological marker of MPXV-infection, whilst MPXV M1 (VACV L1) is likely IMVANEX-specific. Here, we demonstrate analogous humoral antigen recognition between both MPXV-infected or Smallpox-vaccinated individuals, with binding to diverse yet core set of poxvirus antigens, providing opportunities for future vaccine (e.g., mRNA) and therapeutic (e.g., mAbs) design.

A Subunit Vaccine Candidate Composed of Mpox Virus A29L, M1R, A35R, and B6R Elicits Robust Immune Response in Mice

With no specific antiviral drugs and preventive vaccines against Mpox virus (MPXV), the epidemic has led to the declaration of a Public Health Emergency of International Concern. As a developmental direction for new vaccines, studies of subunit vaccines based upon MPXV antigen proteins are lacking. In this study, A29L, M1R, A35R, and B6R of MPXV were expressed and purified from a prokaryotic system. The four MPXV antigen proteins in combination were mixed with aluminum hydroxide or CpG7909 as adjuvant, and subsequently used to inoculate mice. The results of enzyme-linked immunosorbent assay (ELISA), flow cytometry analyses, and enzyme-linked immunospot (ELISPOT) assays indicated that A29L, M1R, A35R, and B6R elicited high-level antigen-specific antibodies and CD4+ T cells-based cellular immune response in mice. Moreover, the results of virus neutralization assays suggested that sera from the mice immunized with four proteins elicited high neutralizing activities against the vaccinia virus. Notably, the results of ELISA, ELISPOT, and virus neutralization assays also showed that the CpG7909 adjuvant was more effective in inducing an immune response compared with the aluminum adjuvant. In summary, this study offers valuable insights for further studies of subunit vaccine candidates for the prevention of MPXV and other orthomyxoviruses.

The prospective outcome of the monkeypox outbreak in 2022 and characterization of monkeypox disease immunobiology

A new threat to global health re-emerged with monkeypox's advent in early 2022. As of November 10, 2022, nearly 80,000 confirmed cases had been reported worldwide, with most of them coming from places where the disease is not common. There were 53 fatalities, with 40 occurring in areas that had never before recorded monkeypox and the remaining 13 appearing in the regions that had previously reported the disease. Preliminary genetic data suggest that the 2022 monkeypox virus is part of the West African clade; the virus can be transmitted from person to person through direct interaction with lesions during sexual activity. It is still unknown if monkeypox can be transmitted via sexual contact or, more particularly, through infected body fluids. This most recent epidemic's reservoir host, or principal carrier, is still a mystery. Rodents found in Africa can be the possible intermediate host. Instead, the CDC has confirmed that there are currently no particular treatments for monkeypox virus infection in 2022; however, antivirals already in the market that are successful against smallpox may mitigate the spread of monkeypox. To protect against the disease, the JYNNEOS (Imvamune or Imvanex) smallpox vaccine can be given. The spread of monkeypox can be slowed through measures such as post-exposure immunization, contact tracing, and improved case diagnosis and isolation. Final Thoughts: The latest monkeypox epidemic is a new hazard during the COVID-19 epidemic. The prevailing condition of the monkeypox epidemic along with coinfection with COVID-19 could pose a serious condition for clinicians that could lead to the global epidemic community in the form of coinfection.

An Updated Review on Monkeypox Viral Disease: Emphasis on Genomic Diversity

Monkeypox virus has remained the most virulent poxvirus since the elimination of smallpox approximately 41 years ago, with distribution mostly in Central and West Africa. Monkeypox (Mpox) in humans is a zoonotically transferred disease that results in a smallpox-like disease. It was first diagnosed in 1970 in the Democratic Republic of the Congo (DRC), and the disease has spread over West and Central Africa. The purpose of this review was to give an up-to-date, thorough, and timely overview on the genomic diversity and evolution of a re-emerging infectious disease. The genetic profile of Mpox may also be helpful in targeting new therapeutic options based on genes, mutations, and phylogeny. Mpox has become a major threat to global health security, necessitating a quick response by virologists, veterinarians, public health professionals, doctors, and researchers to create high-efficiency diagnostic tests, vaccinations, antivirals, and other infection control techniques. The emergence of epidemics outside of Africa emphasizes the disease's global significance. Increased monitoring and identification of Mpox cases are critical tools for obtaining a better knowledge of the ever-changing epidemiology of this disease.

Insights into the challenging multi-country outbreak of Mpox: a comprehensive review

Human monkeypox virus (hMpoxV) is of zoonotic origin and is closely related to the once-dreaded smallpox virus. It is largely endemic to the African continent but has moved out of the endemic regions as sporadic clusters in the past 20 years, raising concerns worldwide. Human Mpox is characterized by a mild to severe, self-limiting infection, with mortality ranging from less than 1% to up to 10% during different outbreaks caused by different clades of MpoxV. Bushmeat hunting is one of the primary reasons for its transmission from animals to humans. Various international and national health regulatory bodies are closely monitoring the disease and have laid down guidelines to manage and prevent hMpox cases. Emergency Use Status has been granted to Tecovirimat and Brincidofovir to treat severe cases and vaccination with the smallpox vaccine is recommended for high-risk group individuals. Strategies to repurpose and discover novel therapeutics and vaccines to control the outbreak are being researched. The current Mpox outbreak that has mainly affected men as approximately 96% of all cases are reported in men, is probably the result of a complex intersection of various factors. This necessitates a strong One Health response coordination involving human, animal and environmental health institutions. This review is an attempt to provide an all-inclusive overview of the biology, history, epidemiology, pathophysiology, diagnosis and management of hMpox in context to the recent 2022-2023 multi-country outbreak which is termed by WHO a 'Public Health Emergency of International Concern (PHEIC)'.

Mpox Virus: Its Molecular Evolution and Potential Impact on Viral Epidemiology

Mpox (previously known as monkeypox) is an infectious viral illness caused by the mpox virus (MPXV), an orthopoxvirus that belongs to the family Poxviridae. The symptoms of mpox in humans are similar to those of smallpox, although the mortality rate is lower. In recent years, the concern over a potential global pandemic has increased due to reports of mpox spreading across Africa and other parts of the world. Prior to this discovery, mpox was a rare zoonotic disease restricted to endemic regions of Western and Central Africa. The sudden emergence of MPXV cases in multiple regions has raised concerns about its natural evolution. This review aims to provide an overview of previously available information about MPXV, including its genome, morphology, hosts and reservoirs, and virus-host interaction and immunology, as well as to perform phylogenetic analysis on available MPXV genomes, with an emphasis on the evolution of the genome in humans as new cases emerge.

Emergence, phylogeography, and adaptive evolution of mpox virus

Mpox (Monkeypox) is a zoonotic disease caused by mpox virus (MPXV). A multi-country MPXV outbreak in non-endemic demographics was identified in May 2022. A systematic evaluation of MPXV evolutionary trajectory and genetic diversity could be a timely addition to the MPXV diagnostics and prophylaxis. Herein, we integrated a systematic evolution analysis including phylogenomic and phylogeographic, followed by an in-depth analysis of the adaptive evolution and amino acid variations in type I interferon binding protein (IFNα/βBP). Mutations in IFNα/βBP protein may impair its binding capacity, affecting the MPXV immune evasion strategy. Based on the equilibrated data, we found an evolutionary rate of 7.75 × 10 - 5 substitutions/site/year, and an earlier original time (2021.25) of the clade IIb. We further discovered significant genetic variations in MPXV genomes from different regions and obtained six plausible spread trajectories from its intricate viral flow network, implying that North America might have acted as a bridge for the spread of MPXV from Africa to other continents. We identified two amino acids under positive selection in the Rifampicin resistance protein and extracellular enveloped virus (EEV) type-I membrane glycoprotein, indicating a role in adaptive evolution. Our research sheds light on the emergence, dispersal, and adaptive evolution of MPXV, providing theoretical support for mitigating and containing its expansion.

Monkeypox infection elicits strong antibody and B cell response against A35R and H3L antigens

Monkeypox virus (MPXV) resides in two forms; mature and enveloped, and depending on it, distinct proteins are displayed on the viral surface. Here, we expressed two MPXV antigens from the mature, and one from the enveloped form, and tested their reactivity to sera of 11 MPXV recoverees while comparing to sera from recently and past vaccinated individuals. 8 out of 11 recoverees exhibited detectable neutralization levels against Vaccinia Lister. Sera from all recoverees bound strongly to A35R and H3L antigens. Moreover, the responses to A35R were significantly higher within the recoverees compared to both recently and past vaccinated donors. Lastly, A35R- and H3L-specific IgG⁺ B cells ranging from 0.03-0.46% and 0.11-0.36%, respectively, were detected in all recoverees (A35R), and in 9 out of 11 recoverees (H3L). Therefore, A35R and H3L represent MPXV immune targets and could be used in a heat-inactivated serological ELISA for the identification of recent MPXV infection.

Human monkeypox (hMPXV) re-emergence: Host immunity status and current vaccines landscape

Monkeypox virus is a member of the Orthopoxvirus genus and the Poxviridae family. Orthopoxviruses are among the most intricate animal viruses. The pathogenicity of human monkeypox infection has been emphasized in response to its recent emergence in non-endemic countries and the threat of bioterrorism. It is always necessary to take appropriate precautions in exposure to emerging or re-emerging infections. Here, we focus on the current state of the human monkeypox infection outbreak, research & development of immune responses, and clinical interventions to prevent and treat the human monkeypox virus and other human poxviruses.

Mpox diagnostics: Review of current and emerging technologies

Mpox is a zoonotic disease caused by monkeypox virus (MPXV) from the Orthopoxvirus genus. Unprecedented transmission events have led to more than 70 000 cases reported worldwide by October 2022. The change in mpox epidemiology has raised concerns of its ability to establish endemicity beyond its traditional geographical locations. In this review, we discuss the current understanding of mpox virology and viral dynamics that are relevant to mpox diagnostics. A synopsis of the traditional and emerging laboratory technologies useful for MPXV detection and in guiding "elimination" strategies is outlined in this review. Importantly, development in MPXV genomics has rapidly advanced our understanding of the role of viral evolution and adaptation in the current outbreak.

Monkeypox virus diagnosis and laboratory testing

The multi-country outbreak of monkeypox virus (MPXV) infection, while the coronavirus disease 2019 pandemic is still an ongoing issue, has caused a new challenge. The re-emergence of MPXV and the rising incidence in non-endemic countries is turning into an upcoming threat to global health. Hence, rapid identification of the virus with appropriate methodology with the lowest false results plays a critical role in estimating the global extent of the crisis and providing preventive measures. This review summarised the main applicable strategies for primary detection and confirmation of MPXV and highlighted available data in biosafety, requirements, standard operating procedures, specimen collection, transportation and storage of clinical samples, and waste disposal of the viral agent. Also, various assays including molecular techniques, immunoassays, histopathological methods, electron microscopy, genomic sequencing, and cell culture have been illustrated. Moreover, we reflected on current knowledge of the advantages and disadvantages of each approach.

Molecular and immunological diagnosis of Monkeypox virus in the clinical laboratory

The 2022 monkeypox outbreak outside Africa is ongoing. Cases have been reported in Hong Kong and Chongqing, China. In order to better prevent and control the potential spread of monkeypox virus in China, the development of sensitive and reliable detection commercial kits is imminent. This correspondence reviews the existing laboratory assays and related technologies for nucleic acid (PCR) and serological assays for the diagnosis of monkeypox virus to provide reference for the management and decision-making departments. Due to the serological cross-reactivity of orthopoxviruses, PCR is the laboratory test of choice to confirm monkeypox virus infection. We recommend a dual-target PCR approach in which one assay targets a conserved sequence of the Orthopoxvirus genus and the other targets a monkeypox virus specific sequence.

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.

The virology of human monkeypox virus (hMPXV): A brief overview

First described in 1958, the human monkeypox virus (hMPXV) is a neglected zoonotic pathogen closely associated with the smallpox virus. The virus usually spreads via close contact with the infected animal or human and has been endemic mostly in parts of the African continent. However, with the recent increase in trade, tourism, and travel, the virus has caused outbreaks in countries outside Africa. The recent outbreak in 2022 has been puzzling given the lack of epidemiological connection and the possible sexual transmission of the virus. Furthermore, there is limited understanding of the structural and pathogenetic mechanisms that are employed by the virus to invade the host cells. Henceforth, it is critical to understand the working apparatus governing the viral-immune interactions to develop effective therapeutical and prophylactic modalities. Hence, in the present short communication, we summarize the previously reported research findings regarding the virology of the human monkeypox virus.

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.

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..

The resurgence of a neglected orthopoxvirus: Immunologic and clinical aspects of monkeypox virus infections over the past six decades

Monkeypox is a zoonotic Orthopoxvirus which has predominantly affected humans living in western and central Africa since the 1970s. Type I and II interferon signaling, NK cell function, and serologic immunity are critical for host immunity against monkeypox. Monkeypox can evade host viral recognition and block interferon signaling, leading to overall case fatality rates of up to 11%. The incidence of monkeypox has increased since cessation of smallpox vaccination. In 2022, a global outbreak emerged, predominantly affecting males, with exclusive human-to-human transmission and more phenotypic variability than earlier outbreaks. Available vaccines are safe and effective tools for prevention of severe disease, but supply is limited. Now considered a public health emergency, more studies are needed to better characterize at-risk populations and to develop new anti-viral therapies.

Monkeypox 2022 outbreak in non-endemic countries: Open questions relevant for public health, nonpharmacological intervention and literature review

Starting from mid-May 2022, cases of human monkeypox started to rise in several non-endemic countries. By mid-July, more than 17000 confirmed/suspect cases have been reported by at least 82 countries worldwide, with a regular incremental trend. In order to contain the disease diffusion, risk evaluation is crucial to undertake informed decisions and effective communication campaigns. However, since orthopoxvirus infections so far have attracted low attention, due to the eradication of smallpox 40 years ago, and to the confinement of human monkeypox almost exclusively to endemic areas, several unresolved issues concerning natural history, ecology and pathogenesis remain. To this respect, we identified some open questions and reviewed the relevant literature on monkeypoxvirus and/or related orthopoxviruses. The results will be discussed in the perspective of their relevance to public health decisions, particularly those related to non-pharmacological interventions.

Monkeypox: disease epidemiology, host immunity and clinical interventions

Monkeypox virus (MPXV), which causes disease in humans, has for many years been restricted to the African continent, with only a handful of sporadic cases in other parts of the world. However, unprecedented outbreaks of monkeypox in non-endemic regions have recently taken the world by surprise. In less than 4 months, the number of detected MPXV infections has soared to more than 48,000 cases, recording a total of 13 deaths. In this Review, we discuss the clinical, epidemiological and immunological features of MPXV infections. We also highlight important research questions and new opportunities to tackle the ongoing monkeypox outbreak.

In this Review, Ng and colleagues examine the clinical, epidemiological and immunological aspects of monkeypox virus (MPXV) infections, with a focus on mechanisms of host immunity to MPXV. The authors also consider the unique epidemiological and pathological characteristics of the current non-endemic outbreak of the virus and discuss vaccines, therapeutics and outstanding research questions.

Effect of Serial Passage on the Pathogenicity and Immunogenicity of Vaccinia Virus LC16m8 Strain

The phenotype of an attenuated live vaccine depends on gene mutation achieved by, for example, many passages in cultured cells. Viral clones with preferable phenotypes are selected and the causative genetic mutation(s) are later identified. LC16m8 is an example of a highly attenuated smallpox vaccine that was developed and licensed in Japan in the 1970s. LC16m8 was obtained by the passaging of Lister strain, with indicators of small plaque formation and temperature sensitivity as virus phenotypes. This strain can replicate in mammalian cells and provides robust cellular and humoral immunity, as well as long-term immune memory. Recent studies using proteome-wide antigen arrays have revealed that antibody production against LC16m8 and other VACVs differs largely among individuals. Moreover, associations between SNPs in immune-related genes and immune outcomes have been increasingly found. These results lead to predicting adverse events of a vaccine, which is a purpose of vaccinomics. Studies on VACV will continue to contribute to the understanding of host-pathogen interactions and to development of a vaccine for other infectious and non-infectious diseases. Here, we review studies of VACV, including our recent research on LC16m8, with a focus on the phenotype and genotype, and we discuss future research directions.

Monkeypox Virus in Nigeria: Infection Biology, Epidemiology, and Evolution

Monkeypox is a zoonotic disease caused by monkeypox virus (MPXV), which is a member of orthopoxvirus genus. The reemergence of MPXV in 2017 (at Bayelsa state) after 39 years of no reported case in Nigeria, and the export of travelers' monkeypox (MPX) from Nigeria to other parts of the world, in 2018 and 2019, respectively, have raised concern that MPXV may have emerged to occupy the ecological and immunological niche vacated by smallpox virus. This review X-rays the current state of knowledge pertaining the infection biology, epidemiology, and evolution of MPXV in Nigeria and worldwide, especially with regard to the human, cellular, and viral factors that modulate the virus transmission dynamics, infection, and its maintenance in nature. This paper also elucidates the role of recombination, gene loss and gene gain in MPXV evolution, chronicles the role of signaling in MPXV infection, and reviews the current therapeutic options available for the treatment and prevention of MPX. Additionally, genome-wide phylogenetic analysis was undertaken, and we show that MPXV isolates from recent 2017 outbreak in Nigeria were monophyletic with the isolate exported to Israel from Nigeria but do not share the most recent common ancestor with isolates obtained from earlier outbreaks, in 1971 and 1978, respectively. Finally, the review highlighted gaps in knowledge particularly the non-identification of a definitive reservoir host animal for MPXV and proposed future research endeavors to address the unresolved questions.

A Smartphone-Based Rapid Telemonitoring System for Ebola and Marburg Disease Surveillance

We have developed a digital and multiplexed platform for the rapid detection and telemonitoring of infections caused by Ebola and Marburg filoviruses. The system includes a flow cell assay cartridge that captures specific antibodies with microarrayed recombinant antigens from all six species of filovirus, and a smartphone fluorescent reader for high-performance interpretation of test results. Multiplexed viral proteins, which are expandable to include greater numbers of probes, were incorporated to obtain highest confidence results by cross-correlation, and a custom smartphone application was developed for data analysis, interpretation, and communication. The smartphone reader utilizes an opto-electro-mechanical hardware attachment that snaps at the back of a Motorola smartphone and provides a user interface to manage the operation, acquire test results, and communicate with cloud service. The application controls the hardware attachment to turn on LEDs and digitally record the optically enhanced images. Assay processing time is approximately 20 min for microliter amounts of blood, and test results are digitally processed and displayed within 15 s. Furthermore, a secure cloud service was developed for the telemonitoring of test results generated by the smartphone readers in the field. Assay system results were tested with sera from nonhuman primates that received a live attenuated EBOV vaccine. This integrated system will provide a rapid, reliable, and digital solution to prevent the rapid overwhelming of medical systems and resources during EVD or MVD outbreaks. Further, this disease-monitoring system will be useful in resource-limited countries where there is a need for dispersed laboratory analysis of recent or active infections.

Impact of Dengue Virus Serotype 2 Strain Diversity on Serological Immune Responses to Dengue

Dengue is a mosquito-borne disease caused by four dengue virus serotypes (DENV1-4) that are loosely categorized by sequence commonalities and antibody recognition profiles. The highly variable envelope protein (E) that is prominently displayed on the surface of DENV is an essential component of vaccines currently under development, yet the impact of using single strains to represent each serotype in tetravalent vaccines has not been adequately studied. We synthesized chimeric E by replacing highly variable residues from a dengue virus serotype 2 vaccine strain (PUO-218) with those from 16 DENV2 lineages spanning 60 years of antigen evolution. Examining sera from human and rhesus macaques challenged with single strains of DENV2, antibody-E interactions were markedly inhibited or enhanced by residues mainly focused within a 480 Ų footprint displayed on the E backbone. The striking impact of E diversity on polyclonal immune responses suggests that frequent antigen updates may be necessary for vaccines to counter shifts in circulating strains.

Retrospective Proteomic Analysis of Serum After Akhmeta Virus Infection: New Suspect Case Identification and Insights Into Poxvirus Humoral Immunity

Serologic cross-reactivity, a hallmark of orthopoxvirus (OPXV) infection, makes species-specific diagnosis of infection difficult. In this study, we used a variola virus proteome microarray to characterize and differentiate antibody responses to nonvaccinia OPXV infections from smallpox vaccination. The profile of 2 case patients infected with newly discovered OPXV, Akhmeta virus, exhibited antibody responses of greater intensity and broader recognition of viral proteins and includes the B21/22 family glycoproteins not encoded by vaccinia virus strains used as vaccines. An additional case of Akhmeta virus, or nonvaccinia OPXV infection, was identified through community surveillance of individuals with no or uncertain history of vaccination and no recent infection. The results demonstrate the utility of microarrays for high-resolution mapping of antibody response to determine the nature of OPXV exposure.

Povidone Iodine Ointment Application to the Vaccination Site Does Not Alter Immunoglobulin G Antibody Response to Smallpox Vaccine

U.S. military personnel deployed to high-risk areas receive the live vaccinia virus (VACV) smallpox vaccine ACAM2000. VACV shedding from the vaccination site can result in autoinoculation and contact transmission. We previously found that the application of povidone iodine ointment (PIO) to the scarification site reduced viral shedding without altering the antibody response, as measured by plaque reduction neutralization or enzyme-linked immunosorbent assays. In this study, we used protein microarray assays to measure the amount of immunoglobulin G antibody bound to (1) ACAM2000 itself and (2) individual VACV antigens that are present within ACAM2000. We assessed antibody binding in sera from primary smallpox vaccinees who applied PIO to the scarification site beginning on day 7 (PIO group) and from those who did not apply PIO (control group). In both cohorts, the postvaccination antibody response-in terms of antibody binding, both to ACAM2000 and to 11 individual VACV antigens-was significantly greater than the prevaccination response (all p < 0.0001). The postvaccination antibody binding levels of vaccinees in the PIO group did not differ from those of control vaccinees. These findings further support the topical application of PIO, starting on day 7, to reduce the viral shedding associated with smallpox vaccination.

The impact of "omic" and imaging technologies on assessing the host immune response to biodefence agents

Understanding the interactions between host and pathogen is important for the development and assessment of medical countermeasures to infectious agents, including potential biodefence pathogens such as Bacillus anthracis, Ebola virus, and Francisella tularensis. This review focuses on technological advances which allow this interaction to be studied in much greater detail. Namely, the use of “omic” technologies (next generation sequencing, DNA, and protein microarrays) for dissecting the underlying host response to infection at the molecular level; optical imaging techniques (flow cytometry and fluorescence microscopy) for assessing cellular responses to infection; and biophotonic imaging for visualising the infectious disease process. All of these technologies hold great promise for important breakthroughs in the rational development of vaccines and therapeutics for biodefence agents.

A highly specific monoclonal antibody against monkeypox virus detects the heparin binding domain of A27

The eradication of smallpox and the cessation of global vaccination led to the increased prevalence of human infections in Central Africa. Serologic and protein-based diagnostic assay for MPXV detection is difficult due to cross-reactive antibodies that do not differentiate between diverse orthopoxvirus (OPXV) species. A previously characterized monoclonal antibody (mAb 69-126-3-7) against MPXV [1] was retested for cross-reactivity with various OPXVs. The 14.5 kDa band protein that reacted with mAb 69-126-3 was identified to be MPXV A29 protein (homolog of vaccinia virus Copenhagen A27). Amino acid sequence analysis of the MPXV A29 with other OPXV homologs identified four amino acid changes. Peptides corresponding to these regions were designed and evaluated for binding to mAb 69-126-3 by ELISA and BioLayer Interferometry (BLI). Further refinement and truncations mapped the specificity of this antibody to a single amino acid difference in a 30-mer peptide compared to other OPXV homologs. This particular residue is proposed to be essential for heparin binding by VACV A27 protein. Despite this substitution, MPXV A29 bound to heparin with similar affinity to that of VACV A27 protein, suggesting flexibility of this motif for heparin binding. Although binding of mAb 69-126-3-7 to MPXV A29 prevented interaction with heparin, it did not have any effect on the infectivity of MPXV. Characterization of 69-126-3-7 mAb antibody allows for the possibility of the generation of a serological based species-specific detection of OPXVs despite high proteomic homology.

Human antibody responses to the polyclonal Dryvax vaccine for smallpox prevention can be distinguished from responses to the monoclonal replacement vaccine ACAM2000

Dryvax (Wyeth Laboratories, Inc., Marietta, PA) is representative of the vaccinia virus preparations that were previously used for preventing smallpox. While Dryvax was highly effective, the national supply stocks were depleted, and there were manufacturing concerns regarding sterility and the clonal heterogeneity of the vaccine. ACAM2000 (Acambis, Inc./Sanofi-Pasteur Biologics Co., Cambridge, MA), a single-plaque-purified vaccinia virus derivative of Dryvax, recently replaced the polyclonal smallpox vaccine for use in the United States. A substantial amount of sequence heterogeneity exists within the polyclonal proteome of Dryvax, including proteins that are missing from ACAM2000. Reasoning that a detailed comparison of antibody responses to the polyclonal and monoclonal vaccines may be useful for identifying unique properties of each antibody response, we utilized a protein microarray comprised of approximately 94% of the vaccinia poxvirus proteome (245 proteins) to measure protein-specific antibody responses of 71 individuals receiving a single vaccination with ACAM2000 or Dryvax. We observed robust antibody responses to 21 poxvirus proteins in vaccinated individuals, including 11 proteins that distinguished Dryvax responses from ACAM2000. Analysis of protein sequences from Dryvax clones revealed amino acid level differences in these 11 antigenic proteins and suggested that sequence variation and clonal heterogeneity may contribute to the observed differences between Dryvax and ACAM2000 antibody responses.

Identification and characterization of microRNAs in the crab-eating macaque (Macaca fascicularis) using transcriptome analysis

MicroRNAs (miRNAs), with an average length between 16 nt and 26 nt, are small non-coding RNAs that can repress gene expression on the post-transcriptional level. Macaca fascicularis (M. fascicularis), one of the most important nonhuman primate animal models, is widely used in basic and applied preclinical research, especially in studies that involve neuroscience and disease. However, due to the lack of a complete genome sequence, the miRNAs in M. fascicularis have not been completely characterized. In this study, 86 putative M. fascicularis miRNAs were identified using a strategy of our design. The expression of some of these miRNAs in the tissue was confirmed by qRT-PCR. The function and pathway of their targeted genes were analyzed to reveal the potential relevance of miRNA regulation on diseases and physiological processes. The current study provides insight into potential miRNAs and forms a useful knowledge base for the future understanding of the function of miRNAs in M. fascicularis.

Characterizing monkeypox virus specific CD8+ T cell epitopes in rhesus macaques

To characterize T cell epitopes in monkeypox virus (MPXV) infected rhesus macaques, we utilized IFNγ Elispot assay to screen 400 predicted peptides from 20MPXV proteins. Two peptides from the F8L protein, an analog of E9L protein in vaccinia, were found to elicit CD8+ T cell responses. Prediction and in vitro MHC binding analyses suggest that one is restricted by Mamu-A1(⁎)001 and another by Mamu-A1(⁎)002. The Mamu-A1(⁎)002 epitope is completely identical in all reported sequences for variola, vaccinia, cowpox and MPXV. The Mamu-A1(⁎)001 epitope is conserved in MPXV and vaccinia, and has one residue substitution (V6>I) in some cowpox sequences and all variola sequences. Given CD8+ T-cell epitopes from E9L were also identified in humans and mice, our data suggested that F8L/E9L may be a dominant pox viral protein for CD8+ T cell responses, and may be considered as a target when designing vaccines that target pox-specific T cell responses.

Assessment of the protective effect of Imvamune and Acam2000 vaccines against aerosolized monkeypox virus in cynomolgus macaques

To support the licensure of a new and safer vaccine to protect people against smallpox, a monkeypox model of infection in cynomolgus macaques, which simulates smallpox in humans, was used to evaluate two vaccines, Acam2000 and Imvamune, for protection against disease. Animals vaccinated with a single immunization of Imvamune were not protected completely from severe and/or lethal infection, whereas those receiving either a prime and boost of Imvamune or a single immunization with Acam2000 were protected completely. Additional parameters, including clinical observations, radiographs, viral load in blood, throat swabs, and selected tissues, vaccinia virus-specific antibody responses, immunophenotyping, extracellular cytokine levels, and histopathology were assessed. There was no significant difference (P > 0.05) between the levels of neutralizing antibody in animals vaccinated with a single immunization of Acam2000 (132 U/ml) and the prime-boost Imvamune regime (69 U/ml) prior to challenge with monkeypox virus. After challenge, there was evidence of viral excretion from the throats of 2 of 6 animals in the prime-boost Imvamune group, whereas there was no confirmation of excreted live virus in the Acam2000 group. This evaluation of different human smallpox vaccines in cynomolgus macaques helps to provide information about optimal vaccine strategies in the absence of human challenge studies.

Humoral immunity to smallpox vaccines and monkeypox virus challenge: proteomic assessment and clinical correlations

Despite the eradication of smallpox, orthopoxviruses (OPV) remain public health concerns. Efforts to develop new therapeutics and vaccines for smallpox continue through their evaluation in animal models despite limited understanding of the specific correlates of protective immunity. Recent monkeypox virus challenge studies have established the black-tailed prairie dog (Cynomys ludovicianus) as a model of human systemic OPV infections. In this study, we assess the induction of humoral immunity in humans and prairie dogs receiving Dryvax, Acam2000, or Imvamune vaccine and characterize the proteomic profile of immune recognition using enzyme-linked immunosorbent assays (ELISA), neutralization assays, and protein microarrays. We confirm anticipated similarities of antigenic protein targets of smallpox vaccine-induced responses in humans and prairie dogs and identify several differences. Subsequent monkeypox virus intranasal infection of vaccinated prairie dogs resulted in a significant boost in humoral immunity characterized by a shift in reactivity of increased intensity to a broader range of OPV proteins. This work provides evidence of similarities between the vaccine responses in prairie dogs and humans that enhance the value of the prairie dog model system as an OPV vaccination model and offers novel findings that form a framework for examining the humoral immune response induced by systemic orthopoxvirus infection.

Comparative pathology of smallpox and monkeypox in man and macaques

In the three decades since the eradication of smallpox and cessation of routine vaccination, the collective memory of the devastating epidemics caused by this orthopoxvirus has waned, and the human population has become increasingly susceptible to a disease that remains high on the list of possible bioterrorism agents. Research using surrogate orthopoxviruses in their natural hosts, as well as limited variola virus research in animal models, continues worldwide; however, interpretation of findings is often limited by our relative lack of knowledge about the naturally occurring disease. For modern comparative pathologists, many of whom have no first-hand knowledge of naturally occurring smallpox, this work provides a contemporary review of this historical disease, as well as discussion of how it compares with human monkeypox and the corresponding diseases in macaques.

Identification and Characterization of MicroRNAs in Macaca fascicularis by EST Analysis

MicroRNAs (miRNAs) are small noncoding RNAs which repress gene expression at the posttranscriptional level. In this study, an expressed sequence tag (EST)-based combined method was applied for the detection of miRNAs in Macaca fascicularis which is used as a model animal extensively in medical experiments, particularly those involved with neuroscience and disease. Initially, previously known miRNA sequences from metazoans were used to blast with the EST databases of Macaca fascicularis, and then a range of filtering criteria was conducted to remove some pseudo ones. At last a total of 8 novel conserved miRNAs were identified; their functions were further predicted and analyzed. Together, our study provides insight into miRNAs and their functions in Macaca fascicularis, indicating that the EST analysis is an efficient and affordable alternative approach for identifying novel miRNA candidates.

Outbreaks of human monkeypox after cessation of smallpox vaccination

The recent observation of a surge in human monkeypox in the Democratic Republic of the Congo (DRC) prompts the question of whether cessation of smallpox vaccination is driving the phenomenon, and if so, why is re-emergence not universal throughout the historic geographic range of the virus? Research addressing the virus's mechanisms for immune evasion and induction, as well as that directed at elucidating the genes involved in pathogenesis in different viral lineages (West African vs Congo Basin), provide insights to help explain why emergence appears to be geographically limited. Novel vaccines offer one solution to curtail the spread of this disease.

The top five "game changers" in vaccinology: toward rational and directed vaccine development

Despite the tremendous success of the classical "isolate, inactivate, and inject" approach to vaccine development, new breakthroughs in vaccine research are increasingly reliant on novel approaches that incorporate cutting edge technology and advances in innate and adaptive immunology, microbiology, virology, pathogen biology, genetics, bioinformatics, and many other disciplines in order to: (1) deepen our understanding of the key biological processes that lead to protective immunity, (2) observe vaccine responses on a global, systems level, and (3) directly apply the new knowledge gained to the development of next-generation vaccines with improved safety profiles, enhanced efficacy, and even targeted utility in select populations. Here we highlight five key components foundational to vaccinomics efforts: applied immunogenomics, next generation sequencing and other cutting-edge "omics" technologies, advanced bioinformatics and analysis techniques, and finally, systems biology applied to immune profiling and vaccine responses. We believe these "game changers" will play a critical role in moving us toward the rational and directed development of new vaccines in the 21st century.