Biological characteristics, biosafety prevention and control strategies for the 2022 multi-country outbreak of monkeypox

Applying improved ddPCR to reliable quantification of MPXV in clinical settings

Monkeypox virus (MPXV) poses a global health threat. Droplet digital PCR (ddPCR) holds potential as an accurate diagnostic tool for clinical microbiology. However, there is limited literature on the applicability of ddPCR in clinical settings. In this study, the clinical features of patients with MPXV during the initial outbreak in China in June 2023 were reviewed, and an optimized ddPCR method with dilution and/or inhibitor removal was developed to enhance MPXV detection efficiency. Eighty-two MPXV samples were tested from nine different clinical specimen types, including feces, urine, pharyngeal swabs, anal swabs, saliva, herpes fluid, crust, and semen, and the viral load of each specimen was quantified. A comparative analysis was performed with qPCR to assess sensitivity and specificity and to investigate the characteristics of MPXV infection by analyzing viral loads in different clinical specimens. Consequently, common pharyngeal and gastrointestinal symptoms were observed in patients with MPXV. The optimized ddPCR method demonstrated relatively high sensitivity for MPXV quantification in the clinical materials, with a limit of detection of 0.1 copies/μL. This was particularly evident in low-concentration samples like whole blood, semen, and urine. The optimized ddPCR demonstrated greater detection accuracy compared with normal ddPCR and qPCR, with an area under the curve (AUC) of 0.939. Except for crust samples, viral loads in the specimens gradually decreased as the disease progressed. Virus levels in feces and anal swabs kept a high detection rate at each stage of post-symptom onset, and feces and anal swabs samples may be suitable for clinical diagnosis and continuous monitoring of MPXV.

IMPORTANCE

The ddPCR technique proved to be a sensitive and valuable tool for accurately quantifying MPXV viral loads in various clinical specimen types. The findings provided valuable insights into the necessary pre-treatment protocols for MPXV diagnosis in ddPCR detection and the potentially suitable sample types for collection. Therefore, such results can aid in comprehending the potential characteristics of MPXV infection and the usage of ddPCR in clinical settings.

The Feasibility of Elimination of Monkeypox Virus in Nigeria: A Systematic Review

Monkeypox is a zoonotic virus with an increasing incidence in Nigeria, posing significant public health challenges. The virus, related to smallpox, primarily spreads through direct contact with infected animals or humans and has been noted for its potential for wider transmission due to changing ecological and social dynamics. This research aims to evaluate the feasibility of eliminating monkeypox in Nigeria through integrated approaches involving vaccination, public health strategies, and ecological management. Additionally, it seeks to propose a unified public health strategy, incorporating One Health principles, to achieve the elimination of monkeypox in Nigeria. A review of the feasibility of eliminating the monkeypox virus in Nigeria was conducted using databases like Science Direct, Cochrane, PubMed, and Medline. The search was guided by the methodologies and reporting guidelines of the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). The initial search yielded 89 publications, but the number of articles that required examination was reduced after applying selected keywords and evaluating abstracts. We deemed 32 articles relevant to the subject after applying inclusion and exclusion criteria. The findings are analyzed, highlighting their limitations and strengths and discussing practical implications, knowledge gaps, and recommendations for future research. This study provides evidence supporting the feasibility of the elimination of the monkeypox virus in Nigeria. Strategic recommendations for a sustainable public health approach to eliminating monkeypox emphasize preventive measures, community engagement, and ecological preservation. This study will provide critical insights into the feasibility of eliminating monkeypox in Nigeria, offering a model that can be adapted for other regions facing similar challenges. The integration of health, ecological, and community-focused strategies is expected to contribute significantly to global efforts to control and potentially eradicate monkeypox. This research could serve as a foundational study for public health authorities in Nigeria and internationally, informing policy and operational decisions to control and eliminate monkeypox as a public health threat. The monkeypox virus reemerges in Nigeria, increasing mortality rates. Awareness programs should be conducted on its danger, transmission mode, and potential human transmission. Public education on the lack of treatment and vaccines is crucial. Meat inspection laws should be enforced to ensure safe animal consumption.

Structural insight into the assembly and working mechanism of helicase-primase D5 from Mpox virus

The Mpox pandemic, caused by the Mpox virus (or monkeypox virus, MPXV), has gained global attention. The D5 protein, a putative helicase-primase found in MPXV, plays a vital role in viral replication and genome uncoating. Here we determined multiple cryo-EM structures of full-length hexameric D5 in diverse states. These states were captured during ATP hydrolysis while moving along the single-stranded DNA (ssDNA) track. Through comprehensive structural analysis combined with the helicase activity system, we revealed that when the primase domain is truncated or the interaction between the primase and helicase domains is disrupted, the double-stranded DNA (dsDNA) unwinds into ssDNA, suggesting a critical regulatory role of the primase domain. Two transition states bound with ssDNA substrate during unwinding reveals that two ATP molecules were consumed to drive DNA moving forward two nucleotides. Collectively, our findings shed light on the molecular mechanism that links ATP hydrolysis to the DNA unwinding in poxviruses.

Current Status of Epidemiology, Diagnosis, Therapeutics, and Vaccines for the Re-Emerging Human Monkeypox Virus

Monkeypox (Mpox) virus, a member of the Poxviridae family, causes a severe illness similar to smallpox, which is characterized by symptoms such as high fever, rash, and pustules. Human-to-human transmission cases have been reported but remained low since the first recorded case of human infection occurred in the Congo in 1970. Recently, Mpox has re-emerged, leading to an alarming surge in infections worldwide since 2022, originating in the United Kingdom. Consequently, the World Health Organization (WHO) officially declared the '2022-23 Mpox outbreak'. Currently, no specific therapy or vaccine is available for Mpox. Therefore, patients infected with Mpox are treated using conventional therapies developed for smallpox. However, the vaccines developed for smallpox have demonstrated only partial efficacy against Mpox, allowing viral transmission among humans. In this review, we discuss the current epidemiology of the ongoing Mpox outbreak and provide an update on the progress made in diagnosis, treatment, and development of vaccines for Mpox.

Structural basis for the assembly of the DNA polymerase holoenzyme from a monkeypox virus variant

The ongoing global pandemic caused by a variant of the monkeypox (or mpox) virus (MPXV) has prompted widespread concern. The MPXV DNA polymerase holoenzyme, consisting of F8, A22, and E4, is vital for replicating the viral genome and represents a crucial target for the development of antiviral drugs. However, the assembly and working mechanism for the DNA polymerase holoenzyme of MPXV remains elusive. Here, we present the cryo-electron microscopy (cryo-EM) structure of the DNA polymerase holoenzyme at an overall resolution of 3.5 Å. Unexpectedly, the holoenzyme is assembled as a dimer of heterotrimers, of which the extra interface between the thumb domain of F8 and A22 shows a clash between A22 and substrate DNA, suggesting an autoinhibition state. Addition of exogenous double-stranded DNA shifts the hexamer into trimer exposing DNA binding sites, potentially representing a more active state. Our findings provide crucial steps toward developing targeted antiviral therapies for MPXV and related viruses.

Efficacy of the modified vaccinia Ankara virus vaccine and the replication-competent vaccine ACAM2000 in monkeypox prevention

BACKGROUND

Recently, there has been an uptick in reported cases of monkeypox (Mpox) in Africa and across the globe. This prompted us to investigate the efficacy of the two vaccines that can prevent Mpox, the modified vaccinia Ankara virus (MVA) vaccine and ACAM2000 vaccine. We analyzed them to determine their rates of humoral cell responses, adverse events, and rash reactions and used these factors as the primary indicators.

METHODS

This study adapted primary data obtained from the Medline, Google Scholar, and Cochrane Library databases. We included a total of eight studies, three of which explored the ACAM2000 vaccine and five of which explored the JYNNEOS MVA vaccine.

RESULTS

There were significant differences in the rates of humoral responses after inoculation by the two vaccines. JYNNEOS MVA vaccine immunization resulted in a statistically significant increased humoral immune response with an effect size of 81.00 (42.80, 119.21) at a 95% CI and a rash reaction with an effect size of 96.50 (42.09, 235.09.21) at a 95% CI. ACAM2000 resulted in a lesser increase in neutralizing antibodies than JYNNEOS MVA vaccine. Similar findings were identified for the rates of adverse reactions, but the difference was not statistically significant. The differences in rash reaction rates in the two vaccination groups were also not statistically significant.

CONCLUSION

ACAM2000 and JYNNEOS vaccines have proven to be efficient in preventing Mpox even though variations exist in their modes of action and associated significant effects. The nonreplicating nature of JYNNEOS prevents the occurrence of the adverse effects seen with other vaccines.