Evolution of monkeypox virus from 2017 to 2022: In the light of point mutations

Circular RNA vaccines against monkeypox virus provide potent protection against vaccinia virus infection in mice

Since the outbreak of monkeypox (mpox) in 2022, widespread concern has been placed on imposing an urgent demand for specific vaccines that offer safer and more effective protection. Using an efficient and scalable circular RNA (circRNA) platform, we constructed four circRNA vaccines that could induce robust neutralizing antibodies as well as T cell responses by expressing different surface proteins of mpox virus (MPXV), resulting in potent protection against vaccinia virus (VACV) in mice. Strikingly, the combination of the four circular RNA vaccines demonstrated the best protection against VACV challenge among all the tested vaccines. Our study provides a favorable approach for developing MPXV-specific vaccines by using a circular mRNA platform and opens up novel avenues for future vaccine research.

Insights into the emergence and evolution of monkeypox virus: Historical perspectives, epidemiology, genetic diversity, transmission, and preventative measures

In 2022, just before the COVID-19 pandemic ended, many countries noticed a viral monkeypox outbreak. Monkeypox virus, a zoonotic pathogen, causes a febrile illness in humans and resembles smallpox. Prevention strategies encompass vaccination, strict infection control measures, and avoiding contact with infected persons. As monkeypox and related poxviruses continue to pose challenges, ongoing surveillance, early diagnosis, prompt isolation, and effective control measures are crucial for limiting transmission and mitigating the impact of outbreaks on public health. This review provides valuable insights into the evolution of the monkeypox virus and its various modes of transmission, including postmortem transmission, and offers an overall perspective on the guidelines issued by the Government of India to prevent and effectively control the spread of this disease.

Exploring Viral Genome Profile in Mpox Patients during the 2022 Outbreak, in a North-Eastern Centre of Italy

In 2022, an unprecedented outbreak of mpox raged in several nations. Sequences from the 2022 outbreak reveal a higher nucleotide substitution if compared with the estimated rate for orthopoxviruses. Recently, intra-lesion SNVs (single nucleotide variants) have been described, and these have been suggested as possible sources of genetic variation. Until now, it has not been clear if the presence of several SNVs could represents the result of local mutagenesis or a possible co-infection. We investigated the significance of SNVs through whole-genome sequencing analysis of four unrelated mpox cases. In addition to the known mutations harboured by the circulating strains of virus (MPXV), 7 novel mutations were identified, including SNVs located in genes that are involved in immune evasion mechanisms and/or viral fitness, six of these appeared to be APOBEC3-driven. Interestingly, three patients exhibited the coexistence of mutated and wild-type alleles for five non-synonymous variants. In addition, two patients, apparently unrelated, showed an analogous pattern for two novel mutations, albeit with divergent frequencies. The coexistence of mixed viral populations, harbouring non-synonymous mutations in patients, supports the hypothesis of possible co-infection. Additional investigations of larger clinical cohorts are essential to validating intra-patient viral genome heterogeneity and determining the possibility of co-presence events of slightly divergent MPXV strains.

Human monkeypox: An updated appraisal on epidemiology, evolution, pathogenesis, clinical manifestations, and treatment strategies

Monkeypox (Mpox) is a zoonotic viral disease caused by the monkeypox virus (MPXV), a member of the Orthopoxvirus genus. The recent occurrence of Mpox infections has become a significant global issue in recent months. Despite being an old disease with a low mortality rate, the ongoing multicountry outbreak is atypical due to its occurrence in nonendemic countries. The current review encompasses a comprehensive analysis of the literature pertaining to MPXV, with the aim of consolidating the existing data on the virus's epidemiological, biological, and clinical characteristics, as well as vaccination and treatment regimens against the virus.

Molecular evolution of 2022 multi-country outbreak-causing monkeypox virus Clade IIb

The monkeypox virus (Mpoxv) Clade IIb viruses that caused an outbreak in 2017-18 in Nigeria and its genetically related viruses have been detected in many countries and caused multi-country outbreak in 2022. Since the pandemic-causing Mpoxv Clade IIb viruses are closely related to Clade IIa viruses which mostly cause endemic, the Clade IIb Mpoxv might have certain specific genetic variations that are still largely unknown. Here, we have systematically analyzed genetic alterations in different clades of Mpox viruses. The results suggest that the Mpoxv Clade IIb have genetic variations in terms of genomic gaps, frameshift mutations, in-frame nonsense mutations, amino acid tandem repeats, and APOBEC3 mutations. Further, we observed specific genetic variations in the multiple genes specific for Clade I and Clade IIb, and exclusive genetic variations for Clade IIa and Clade IIb. Collectively, findings shed light on the evolution and genetic variations in the outbreak of 2022 causing Mpoxv Clade IIb.

Zoonotic and Zooanthroponotic Potential of Monkeypox

The current multicounty outbreak of monkeypox virus (MPXV) posed an emerging and continued challenge to already strained public healthcare sector, around the globe. Since its first identification, monkeypox disease (mpox) remained enzootic in Central and West African countries where reports of human cases are sporadically described. Recent trends in mpox spread outside the Africa have highlighted increased incidence of spillover of the MPXV from animal to humans. While nature of established animal reservoirs remained undefined, several small mammals including rodents, carnivores, lagomorphs, insectivores, non-human primates, domestic/farm animals, and several species of wildlife are proposed to be carrier of the MPXV infection. There are established records of animal-to-human (zoonotic) spread of MPXV through close interaction of humans with animals by eating bushmeat, contracting bodily fluids or trading possibly infected animals. In contrast, there are reports and increasing possibilities of human-to-animal (zooanthroponotic) spread of the MPXV through petting and close interaction with pet owners and animal care workers. We describe here the rationales and molecular factors which predispose the spread of MPXV not only amongst humans but also from animals to humans. A range of continuing opportunities for the spread and evolution of MPXV are discussed to consider risks beyond the currently identified groups. With the possibility of MPXV establishing itself in animal reservoirs, continued and broad surveillance, investigation into unconventional transmissions, and exploration of spillover events are warranted.

Complete genome reconstruction of the global and European regional dispersal history of the lumpy skin disease virus

IMPORTANCE

Lumpy skin disease virus (LSDV) has a complex epidemiology involving multiple strains, recombination, and vaccination. Its DNA genome provides limited genetic variation to trace outbreaks in space and time. Sequencing of LSDV whole genomes has also been patchy at global and regional scales. Here, we provide the first fine-grained whole genome sequence sampling of a constrained LSDV outbreak (southeastern Europe, 2015-2017), which we analyze along with global publicly available genomes. We formally evaluate the past occurrence of recombination events as well as the temporal signal that is required for calibrating molecular clock models and subsequently conduct a time-calibrated spatially explicit phylogeographic reconstruction. Our study further illustrates the importance of accounting for recombination events before reconstructing global and regional dynamics of DNA viruses. More LSDV whole genomes from endemic areas are needed to obtain a comprehensive understanding of global LSDV dispersal dynamics.

Sign of APOBEC editing, purifying selection, frameshift, and in-frame nonsense mutations in the microevolution of lumpy skin disease virus

The lumpy skin disease virus (LSDV), which mostly affects ruminants and causes huge-economic loss, was endemic in Africa, caused outbreaks in the Middle East, and was recently detected in Russia, Serbia, Greece, Bulgaria, Kazakhstan, China, Taiwan, Vietnam, Thailand, and India. However, the role of evolutionary drivers such as codon selection, negative/purifying selection, APOBEC editing, and genetic variations such as frameshift and in-frame nonsense mutations in the LSDVs, which cause outbreaks in cattle in various countries, are still largely unknown. In the present study, a frameshift mutation in LSDV035, LSDV019, LSDV134, and LSDV144 genes and in-frame non-sense mutations in LSDV026, LSDV086, LSDV087, LSDV114, LSDV130, LSDV131, LSDV145, LSDV154, LSDV155, LSDV057, and LSDV081 genes were revealed among different clusters. Based on the available complete genome sequences, the prototype wild-type cluster-1.2.1 virus has been found in other than Africa only in India, the wild-type cluster-1.2.2 virus found in Africa were spread outside Africa, and the recombinant viruses spreading only in Asia and Russia. Although LSD viruses circulating in different countries form a specific cluster, the viruses detected in each specific country are distinguished by frameshift and in-frame nonsense mutations. Furthermore, the present study has brought to light that the selection pressure for codons usage bias is mostly exerted by purifying selection, and this process is possibly caused by APOBEC editing. Overall, the present study sheds light on microevolutions in LSDV, expected to help in future studies towards disturbed ORFs, epidemiological diagnostics, attenuation/vaccine reverts, and predicting the evolutionary direction of LSDVs.

Differences in pathogenicity among the mpox virus clades: impact on drug discovery and vaccine development

Since May 2022, mpox virus (MPXV) has attracted considerable attention due to a multi-country outbreak. Marked differences in epidemiology, transmission, and pathology between the 2022 global mpox outbreak (clade IIb) and classical mpox disease, endemic in Africa (clades I and IIa) have been highlighted. MPXV genome analysis has identified the genomic changes characterizing clade IIb and the drivers of MPXV rapid evolution. Although mpox cases have largely declined, MPXV cryptic transmission and microevolution continues, which may lead to an MPXV of unpredictable pathogenicity. Vaccines and antivirals developed against variola virus, the agent that caused the extinguished plague smallpox, have been used to contain the 2022 mpox outbreak. In this review article, recent findings on MPXV origin and evolution and relevant models able to recapitulate differences in MPXV pathogenicity, which are important for drug and vaccine development, are discussed.

Non-adaptive evolution in codon usage of human-origin monkeypox virus

Monkeypox virus (Mpox) is a zoonotic infectious disease that threatens human and animal health, with a global outbreak of the low-pathogenic Mpox beginning from 2022. In this study, we analyzed the codon usage of Mpox between two clades, Clade-I and Clade-IIb-B, to understand changes in host adaptation. Clade-IIb-B of the Mpox genome underwent non-adaptive evolution making it less adapted to its host than Clade-I. The analysis of individual genes revealed that 48 genes exhibited non-adaptive mutation, while 38 genes underwent adaptive mutations. Genes involved in replication, transcription, and host-modulation exhibited a mix of adaptive and non-adaptive evolutionary patterns. This study also found that the mutations of Mpox led to changes in non-adaptative genes in different organs. Additionally, we found that codon usage of Mpox was less similar to that of up-regulated host genes and more similar to that of down-regulated host genes post-infection, indicating that codon usage affects host gene expression. Overall, the study highlights the non-adaptive changes in codon usage as a potential cause of differences in Mpox virulence and provides insights into the evolutionary and adaptive mechanisms of Mpox and its potential impact on pathogenicity and host adaptation.

Human monkeypox: history, presentations, transmission, epidemiology, diagnosis, treatment, and prevention

Human monkeypox is a zoonotic infection that is similar to the diseases caused by other poxviruses. It is endemic among wild rodents in the rainforests of Central and Western Africa, and can be transmitted via direct skin contact or mucosal exposure to infected animals. The initial symptoms include fever, headache, myalgia, fatigue, and lymphadenopathy, the last of which is the main symptom that distinguishes it from smallpox. In order to prevent and manage the disease, those who are infected must be rapidly diagnosed and isolated. Several vaccines have already been developed (e.g., JYNNEOS, ACAM2000 and ACAM3000) and antiviral drugs (e.g., cidofovir and tecovirimat) can also be used to treat the disease. In the present study, we reviewed the history, morphology, clinical presentations, transmission routes, diagnosis, prevention, and potential treatment strategies for monkeypox, in order to enable health authorities and physicians to better deal with this emerging crisis.

Insights into the Evolution and Host Adaptation of the Monkeypox Virus from a Codon Usage Perspective: Focus on the Ongoing 2022 Outbreak

The exceptionally widespread outbreak of human monkeypox, an emerging zoonosis caused by the monkeypox virus (MPXV), with more than 69,000 confirmed cases in 100 non-endemic countries since 2022, is a major public health concern. Codon usage patterns reflect genetic variation and adaptation to new hosts and ecological niches. However, detailed analyses of codon usage bias in MPXV based on large-scale genomic data, especially for strains responsible for the 2022 outbreak, are lacking. In this study, we analyzed codon usage in MPXV and its relationship with host adaptation. We confirmed the ongoing outbreak of MPXVs belonging to the West Africa (WA) lineage by principal component analysis based on their codon usage patterns. The 2022 outbreak strains had a relatively low codon usage bias. Codon usage of MPXVs was shaped by mutation and natural selection; however, different from past strains, codon usage in the 2022 outbreak strains was predominantly determined by mutation pressure. Additionally, as revealed by the codon adaptation index (CAI), relative codon deoptimization index (RCDI), and similarity index (SiD) analyses, the codon usage patterns of MPXVs were also affected by their hosts. In particular, the 2022 outbreak strains showed slightly but significantly greater adaptation to many primates, including humans, and were subjected to stronger selection pressure induced by hosts. Our results suggest that MPXVs contributing to the 2022 outbreak have unique evolutionary features, emphasizing the importance of sustained monitoring of their transmission and evolution.

Lumpy Skin Disease—An Emerging Cattle Disease in Europe and Asia

Lumpy skin disease virus (LSDV) is a member of the Capripoxvirus genus, mainly infecting cattle and buffalo, which until relatively recently was only endemic in parts of Africa and then spread to the Middle East and lately Europe and Asia. Lumpy skin disease (LSD) is a notifiable disease with a serious impact on the beef industry as it causes mortality of up to 10% and has impacts on milk and meat production, as well as fertility. The close serological relationship between LSDV, goat poxvirus (GTPV) and sheep poxvirus (SPPV) has led to live attenuated GTPV and SPPV vaccines being used to protect against LSD in some countries. There is evidence that the SPPV vaccine does not protect from LSD as well as the GTPV and LSDV vaccines. One of the LSD vaccines used in Eastern Europe was found to be a combination of different Capripoxviruses, and a series of recombination events in the manufacturing process resulted in cattle being vaccinated with a range of recombinant LSDVs resulting in virulent LSDV which spread throughout Asia. It is likely that LSD will become endemic throughout Asia as it will be very challenging to control the spread of the virus without widespread vaccination.

Mpox, Caused by the MPXV of the Clade IIb Lineage, Goes Global

Mpox is a great public health concern worldwide currently; thus, a global primary epidemiological analysis of mpox and a phylogenetic analysis of currently circulating MPXV strains based on open-source data is necessary. A total of 83,419 confirmed cases with 72 deaths were reported from 7 May to 23 December 2022, representing an ongoing increasing trend. Mpox was largely restricted to being endemic in children in West Africa (WA) before 2022, and it mainly spread from animals to humans. Our analysis highlights that mpox has not only spread across regions within Africa but has also led to most infection events outside Africa. Currently, mpox has been dominated by human-to-human spread in 110 countries, with the majority of cases distributed in the non-endemic regions of Europe and North America. These data indicate that the geographic range, transmission route, vulnerable populations, and clinical manifestations of mpox have changed, which suggests that the niche of mpox has the potential to change. Remarkably, approximately 38,025 suspected mpox cases were recorded in West and Central Africa during 1970-2022, which implied that the epidemiology of mpox in the two regions remained cryptic, suggesting that strengthening the accuracy of molecular diagnosis on this continent is a priority. Moreover, 617 mpox genomes have been obtained from 12 different hosts; these data imply that the high host diversity may contribute to its ongoing circulation and global outbreak. Furthermore, a phylogenetic analysis of 175 MPXV genome sequences from 38 countries (regions) showed that the current global mpox outbreak was caused by multiple sub-clades in the clade IIb lineage. These data suggest that MPXV strains from the clade IIb lineage may play a predominated role in the spread of mpox worldwide, implying that the current mpox outbreak has a single infection source. However, further investigations into the origin of the new global mpox outbreak are necessary. Therefore, our analysis highlights that adjusted timely interventive measures and surveillance programs, especially using cheap and quick strategies such as wastewater monitoring the DNA of MPXV in Africa (WA), are important for uncovering this disease's transmission source and chain, which will help curb its further spread.