Showing posts with label orthopoxvirus. Show all posts
Showing posts with label orthopoxvirus. Show all posts

Thursday, April 30, 2026

#Orthopoxvirus #Antibodies in Feral #Mammals in #Mpox #Outbreak Areas, #Nigeria, 2021–2022

 


Abstract

We analyzed tissue and serum samples from 124 wild animals from communities with confirmed mpox cases in Nigeria. Tissue samples were PCR-negative, but serum samples from 8 animals (6.45%)—3 feral cats, 4 giant pouched rats, and 1 shrew—revealed Orthopoxvirus antibodies, suggesting these species as probable reservoirs.

Source: 


Link: https://wwwnc.cdc.gov/eid/article/32/5/25-1565_article

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Tuesday, March 10, 2026

Immunogenicity and #safety of MVA-BN #vaccine administered 5 years after a two-dose primary series in #DRC: a prospective cohort study

 


Summary

Background

The expanding mpox outbreak in Africa and travel-associated cases in other continents have increased efforts to vaccinate populations at high risk. This study aimed to assess serological immune responses 5 years after individuals received a primary vaccination (two-dose series) with the smallpox and mpox vaccine modified vaccinia Ankara-Bavarian Nordic (MVA-BN), as well as to evaluate the safety and immunogenicity of a third dose (booster). To date, there are no data for immunological memory or third-dose-induced immunity for MVA-BN at these long-term timescales.

Methods

In this open-label, prospective cohort extension, we re-enrolled health-care workers from a 2017 vaccination study in Bokungu Health Zone, DR Congo, to receive a third dose of MVA-BN. All previous participants were offered the opportunity to re-enrol. Participants were grouped according to whether they had received a childhood smallpox vaccination with a replication-competent vaccine strain (historically vaccinated group) or had no history of smallpox vaccination (historically naive group). Participants were excluded from serological analyses if they had any history of mpox or mpox-like lesion-presenting illness, if their previous vaccination status during initial enrolment for the primary series was unknown, or if they had discordant vaccination information. The coprimary outcomes were sustained humoral immunity following primary vaccination with MVA-BN (5 years previously) and the immunogenicity and safety of the booster vaccination. Safety was analysed in patients with a completed immediate adverse event form or adverse event diary. Adverse events were assessed on days 0 (within 30 min of the booster), 7, and 14. Antibody responses were measured by ELISA, plaque reduction neutralisation tests, and endpoint titre at re-enrolment (day 0, before administration of the booster dose) and on days 7, 14, and 545 after the booster dose.

Findings

Between Sept 7 and 15, 2022, 170 (66·1%) of 257 Bokungu health-care personnel vaccinated in 2017 were re-enrolled to receive a third (booster) dose of MVA-BN. At re-enrolment, low levels of circulating antibody were observed, but 30 (61%) of 49 historically naive participants and 95 (96%) of 99 historically vaccinated participants with childhood smallpox vaccination remained seropositive 5 years after the primary MVA-BN two-dose series. After the third dose, there was a rapid and massive increase in anti-orthopoxvirus IgG but not IgM, and a 93-fold rise in orthopoxvirus neutralising antibody titres was observed by day 14 in historically naive participants, irrespective of participants' seropositivity at the time of booster vaccination. The third dose resulted in enhanced durability of circulating antibody concentrations, with endpoint titres on day 545 remaining more than six-fold higher than day 0 values. There was a greater risk of local reactogenicity after the booster dose than after the primary vaccination (relative risk 4·2, 95% CI 2·81–6·46), but there was no difference in the risk of systemic adverse events up to day 7 after vaccination. No grade 3 serious adverse events were recorded after booster dose administration.

Interpretation

These data show that primary MVA-BN vaccination induces sustained immunological memory up to 5 years after vaccination and that a booster dose strongly enhances circulating antibody levels and durability. Future studies should clarify the role of circulating antibody concentrations as a correlate of protection from monkeypox virus infection.

Funding

US Centers for Disease Control and Prevention and US Biomedical Advanced Research and Development Authority.

Translation

For the French translation of the abstract see Supplementary Materials section.

Source: 


Link: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(26)00001-0/fulltext?rss=yes

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Case presentation of #patients hospitalised with #mpox (subclade Ib/2023sh) including #children, #adolescents, and #adults in South Kivu, #DRC: an observational cohort study

 


Summary

Background

Mpox is a public health concern in eastern DR Congo. It continues to cause substantial numbers of hospital admissions, with changing demographics including children and adolescents, requiring comprehensive clinical and epidemiological investigation. In this study, we aim to describe the clinical characteristics of hospitalised participants infected with monkeypox virus (MPXV) subclade Ib/2023sh in the Kabare Territory in South Kivu, DR Congo.

Methods

This observational cohort study included patients admitted with suspected mpox to the reference centre of mpox treatment at Lwiro Hospital, South Kivu, DR Congo. Eligible participants must have had, at the time of inclusion, skin lesions compatible with the infection. Individuals who did not present lesions compatible with MPXV infection were also eligible if they had at least one of the following symptoms: fever, cervical lymphadenopathy, or pharyngitis, provided they had been in contact with someone with suspected mpox within the last 21 days. Data from hospital records and standardised clinical forms captured demographics, presenting symptoms and signs, outcomes, and general clinical characteristics. Descriptive analyses and statistics summarised the clinical and epidemiological profiles of participants with molecular confirmation of MPXV subclade Ib/2023sh.

Findings

Between Aug 3, 2024, and Feb 8, 2025, MPXV subclade Ib/2023sh was detected in 494 (77%) of 643 participants with a median age of 9 years (IQR 2–24). Participants who were positive for MPXV subclade Ib/2023sh infection were more often female (290 [59%]) and were generally older (median 16 years [4–25]) than male participants (204 [41%]; median age 4 years [1–14]). 300 (61%) of 494 participants were aged 15 years or younger. Fever (444 [90%]), skin lesions or rash (391 [79%]), and dysphagia (279 [56%]) were the most prevalent symptoms. Children aged 0–5 years had a higher frequency of lesions on the head (84 [41%] of 203), face (67 [33%]), neck (23 [11%]), back (27 [13%]), arm (35 [17%]), palm of hand (35 [17%]), chest (46 [23%]), posterior aspect of thighs (40 [20%]), legs (25 [12%]), dorsal foot (45 [22%]), and oral cavity (37 [18%]). 117 (24%) participants had lesions in the oral cavity. Oral cavity and oropharynx swabs were able to detect MPXV subclade Ib/2023sh in the absence of assayable skin lesions.

Interpretation

The high proportion of children and adolescents (aged ≤15 years) differentiates our cohort from other clinical descriptions of the novel MPXV subclade Ib/2023sh. Given that, we hypothesise a demographic shift in the target population that contributes to the community spread of mpox in the South Kivu region of DR Congo. Targeted public health measures should consider ways to reduce transmission among children and adolescents.

Funding

Canadian Institutes of Health Research (CIHR), Canadian Foundation for Innovation, Research Nova Scotia, Dalhousie Medical Foundation, Moderna, Li-Ka Shing Foundation, European & Developing Countries Clinical Trials Partnership (EDCTP).

Translations

For the French, Swahili and Mashi translations of the abstract see Supplementary Materials section.

Source: 


Link: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(26)00051-4/fulltext?rss=yes

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Saturday, February 28, 2026

#Genomic Characterization of the Index Case of #Human #Monkeypox Virus Infection in #Mali, 2025

 


Abstract

Mpox is a zoonosis caused by the monkeypox virus. Here, we report Mali’s index Mpox case, which was clinically identified at the Mali–Guinea border by the national telemedicine center and confirmed by PCR. The library prepared with NextGenPCR™ MPXV Sequencing Library Prep and sequenced on Minion MK1C revealed a genome length of 197,122 bp with an average depth of 1284.4×. The strain belonged to Clade IIb G1 lineage and exhibited 85 mutations relative to NC_063383.1. To decipher genomic epidemiology, genomes ≥ 195 kb were retrieved from NCBI and aligned with MAFFT. Time-resolved phylogenetic reconstruction and ancestral trait inference were performed with TreeTime v0.11.4. A median joining network was built with Popart v1.7. Phylogeographic analysis revealed clustering with Clade IIb (G.1 lineage) linked to the May 2025 outbreak in Sierra Leone.

Source: 


Link: https://www.mdpi.com/1999-4915/18/3/294

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Wednesday, February 25, 2026

#Mpox Multi-country external #situation #report no. 63, published 24 February 2026 (#WHO, summary)

 


Highlights   

Transmission of mpox continues in sexual networks, affecting both women and men, and in some historically endemic areas

- All clades of monkeypox virus (MPXV) continue to circulate. 

- Unless mpox outbreaks are rapidly contained and human-to-human transmission is interrupted, there is a risk of sustained community transmission

In January 2026, 50 countries across all WHO regions reported a total of 1334 new confirmed mpox cases, including three deaths (case fatality ratio [CFR] 0.2%). 

- Of these cases, 66% were reported in the African Region. 

Four regions observed a decline in confirmed cases in January, compared to December 2025, while the European Region reported an increase in confirmed cases.

Twenty countries in Africa reported active transmission of mpox in the last six weeks (5 January – 15 February 2026), with 1142 confirmed cases, including four deaths (CFR 0.4%). 

- Countries reporting the highest number of cases in this period are the Democratic Republic of the Congo, Guinea, Madagascar, Liberia and Ghana

One country, Comoros, and one territory, La RĂ©union (Overseas Department of France), have reported mpox due to clade Ib MPXV for the first time.   

Outside Africa, reports of community transmission of clade Ib MPXV continue in France, Portugal and Spain, including in sexual networks of men who have sex with men.  

WHO conducted a global mpox rapid risk assessment in February 2026; the overall global public health risk associated with the mpox multi-country outbreak was assessed as moderate. 

India has reported a case of mpox with the clade Ib /IIb recombinant MPXV. 

- The strain sequenced is closely related to the first clade Ib / IIb recombinant strain reported by the United Kingdom of Great Britain and Northern Ireland in December 2025. 

- As both cases are travel-related, these case reports suggest wider transmission of the recombinant strain, implicating four countries in three WHO regions. 

(...)

Source: 


Link: https://www.who.int/publications/m/item/multi-country-outbreak-of-mpox--external-situation-report--63---24-february-2026

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Wednesday, February 18, 2026

#MPOX, Multi-Country: Rapid #risk #assessment, 7 February 2026, v6 (#WHO, Feb. 18 '26)

 


{Excerpt}

Overall Global Risk Statement  

-- This global rapid risk assessment (RRA) aims to assess the current public health risk associated with the 2024 upsurge of mpox in in Africa, in the context of the continuing global reporting of mpox cases in other regions since 2022, with a focus on updates since the previous RRA in September 2025.    

Global overview 

-- As of 28 January 2026, the monkeypox virus (MPXV) continues to spread globally, causing both localized and extended mpox outbreaks driven by various MPXV clades (Ia, Ib, IIa, and IIb) in diverse settings. 

-- Furthermore, recombination of MPXV clades has been documented, with two cases of a recombinant clade Ib/IIb MPXV strain reported in recent months.  

-- Globally, from 1 January 2022 to 31 December 2025 (latest global data available), 143 countries and territories across all WHO regions have reported 177 848 confirmed cases, including 477 deaths (case fatality ratio [CFR] – 0.3%)

-- This marks an increase of five additional reporting countries (Kuwait, Mali, Madagascar, Namibia and Senegal), along with an additional 19 423 confirmed cases and 78 deaths since the last RRA in September 2025. 

-- Since the last RRA, an average of 616 new confirmed mpox cases per week have been reported across all affected countries.

-- In addition, in January 2026, the Comoros and the French departments of Mayotte and la RĂ©union have reported cases linked to travel to Madagascar.  

-- Previous versions of this RRA have categorized risk based on MPXV clade. However, in absence of substantial data suggesting differences in the mode of transmission between different MPXV clades, and with relatively limited data suggesting higher case fatality for clade Ia MPXV compared to other clades, this version of the RRA assesses the risk for three population groups:

- global risk for individuals with multiple sexual partners, 

- local risk for children in mpox historically endemic areas, and 

- global risk for all other individuals.   


Individuals with multiple sexual partners – global risk  

-- Since the start of the global mpox outbreak in 2022, sexual activity in linked sexual networks has been the primary driver of sustained transmission and geographic spread, particularly in newly affected areas. 

-- In Europe and the Americas, up to 96% of cases were among men who have sex with men driven by spread among individuals with multiple sexual partners in a short space of time and frequent partner change. 

-- While sexual behavior data for cases in newly affected African countries remain limited, the contribution of sexual transmission to the introduction, spread and establishment of mpox in communities has been recognized across all affected settings, as in the most recent outbreak in Madagascar

-- In several countries, transmission has involved sex workers and their clients, and sexual networks with frequent and multiple partner change.  

-- Sexual contact infection likely occurs during pre-symptomatic or less apparent stages of infection, the duration of which can vary between individuals. 

-- People with few or mild genital lesions might not even recognise the infection. 

-- Although the secondary attack rate for sexual contact is high (estimated at 16-73%), for the epidemic to spread it requires networks characterised by frequent partner change and high rates of partner turnover over short timeframe (days to few weeks). 

-- This pattern was observed during the initial spread of clade IIb among communities of men who have sex with men, as well as in more recent MPXV clade Ib oubtreaks driven – in part – by key populations such as female sex workers and their clients

-- We therefore consider within this group of multiple sexual partners, individuals with frequent partner change, and those who may engage in at-risk sexual behaviour, such as people who buy sex.  

(...)

Source: 


Link: https://www.who.int/publications/m/item/who-rapid-risk-assessment---mpox--global-v.6

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Monday, February 16, 2026

#Mpox: #recombinant virus with genomic elements of clades Ib and IIb - Global (#WHO, Feb. 16 '26)

 


Situation at a glance

Recombination of monkeypox virus (MPXV) strains has been documented in recent months, with two cases of a recombinant strain comprising clade Ib and IIb MPXV reported. 

Recombination is a known natural process that can occur when two related viruses infecting the same individual exchange genetic material, producing a new virus. 

The first case was detected in the United Kingdom of Great Britain and Northern Ireland (hereafter “United Kingdom”), with travel history to a country in South-East Asia, and the second in India, with travel history to a country in the Arabian Peninsula

Detailed analysis of the virus genomes shows that the two individuals fell ill several weeks apart with the same recombinant strain, suggesting that there may be further cases than are currently reported

Both cases had similar clinical presentation to that observed for other clades. 

Neither patient experienced severe outcomes. 

Contact tracing for both cases in the reporting countries has been completed; no secondary cases were detected. 

Based on available information, the overall WHO public health risk assessment for mpox remains unchanged: the risk is assessed as moderate for men who have sex with men with new and/or multiple partners and for sex workers or others with multiple casual sexual partners, and low for the general population without specific risk factors.


Description of the situation

In December 2025, the United Kingdom detected the first reported case of a clade Ib/IIb MPXV recombinant strain.​​ After classification of this case and posting in a public database as a novel MPXV recombinant strain, a case of mpox detected in India in September 2025 was retrospectively reclassified as a closely-related recombinant strain based on sequencing data. To date, these are the only known cases of this recombinant virus.  


Case detected in the United Kingdom of Great Britain and Northern Ireland 

The case was identified following testing of a vesicular swab from a traveler who had returned from a country in the Asia Pacific region in October 2025. 

During laboratory confirmation, the virus was initially typed as clade Ib MPXV by qPCR. 

Subsequent whole genome sequencing revealed that the MPXV strain identified was distinct from other known clade Ib MPXV strains with phylogenetic analysis indicating that the genome had regions similar to both clade Ib and clade IIb MPXV reference sequences, suggesting that it is an inter-clade recombinant

To confirm this unusual finding, sequencing was repeated on the original extract from the primary sample, a fresh extract from the same primary sample, a second swab collected from the patient at the same time, and a cultured isolate derived from the initial swab. 

This repeat sequencing yielded identical viral genome sequences from the two clinical swabs and the cultured isolate, supporting the initial findings of a new recombinant strain, and showing that it can replicate and presents potential for onward transmission. 

This strain is a recombinant MPXV, containing genetic elements from both clade Ib and clade IIb MPXV. 

A small number of contacts were identified and followed up in the United Kingdom; none developed any clinical features of mpox. 

Health worker contacts had worn full personal protective equipment (PPE) during provision of medical care to the patient. 

The authorities of the United Kingdom continue to investigate the significance of this recombinant MPXV strain through phenotypic characterization studies. 


Case detected in India

On 13 January 2026, the National IHR Focal Point (NFP) of India notified WHO of a mpox case with an inter‑clade recombinant MPXV which was, upon whole-genome sequencing, found to have genomic elements of clades Ib and IIb MPXV.

The recombinant virus was found in samples from a man with mpox who had presented for care in September 2025. The patient had reported recent travel from a country in the Arabian Peninsula, where he resides as an overseas worker.

He developed symptoms on 1 September 2025, while still abroad. After his return to India, real‑time PCR confirmed MPXV infection on 11 September 2025. 

Clade differentiation PCR performed on 15 September 2025 initially identified this virus as clade II MPXV. Initial genomic sequencing analysis suggested features consistent with clade IIb MPXV. However, following the update of the global Nextclade database on 16 December 2025, which included the recombinant clade Ib/IIb MPXV strain reported by the United Kingdom, the virus from the patient in India was reclassified as belonging to the recombinant strain. 

Recombination analysis demonstrated mosaic patterns containing genomic regions derived from both parent clades.

Following the initial diagnosis, the patient was hospitalized, did not experience any medical complications, and fully recovered, testing negative for MPXV on 29 September 2025. The case reported no close contacts in India, and no known secondary cases were identified following this introduction of the recombinant clade Ib/IIb MPXV in India.

Full or near‑full genome retrieval (>99%) from both the sample and a sample-derived virus isolate enabled phylogenetic analysis showing >99.9% similarity to the recombinant strain detected in the United Kingdom

A total of 34 recombinant tracts were observed in the sequence reported by India, while 28 recombinant tracts were observed in the sequence reported by the United Kingdom; 16 recombinant tracts were common to both strains.  

This case in India therefore represents the earliest known detection of this recombinant strain globally, having preceded the event reported in the United Kingdom.

Consistent with the case reported in the United Kingdom, clinical presentation was consistent with cases due to clade I or clade II MPXV (non-recombinant MPXV) infection.


Epidemiology

Mpox is an infectious disease caused by the MPXV, which is part of the genus Orthopoxvirus, that includes the variola virus, the causative agent for smallpox. 

There are two known clades of MPXV: clade I (previously called the Congo Basin clade), which includes subclades Ia and Ib; and clade II (previously called the West Africa clade), which includes subclades IIa and clade IIb

Subclades Ia and Ib were defined after the emergence of subclade Ib in the South Kivu province of the Democratic Republic of the Congo in 2023, and subclade Ia encompasses all other strains of clade I that are not Ib.

As reported here, there have also been two cases of the clade Ib/IIb recombinant strain, detected in the UK and in India.

Mpox spreads among humans through direct close physical contact with an infected person, including sexual contact

Transmission can also occur through indirect contact (with contaminated materials), through infectious respiratory particles in limited cases, and from mother to child (vertical transmission).

Historically mpox was primarily characterized by zoonotic transmission, with outbreaks occurring in tropical rainforest regions of East, Central and West Africa, and occasional exportation of cases to other areas. 

In the context of zoonotic transmission, which continues to occur in historically endemic areas, MPXV is transmitted to humans through direct contact with infected wild animals (e.g., through hunting, trapping, or petting), and possibly through processing and consuming infected wild game or their body parts and fluids

To date, animal-to-human transmission has always been documented in or linked to known endemic regions of Africa. 

All other outbreaks in Africa or in other parts of the world are to date presumed to be due to human-to-human transmission, until proven otherwise. 

Symptoms of mpox in humans include: 

- swollen lymph nodes, 

- fever, and 

- a skin rash and/or mucosal lesions that may initially resemble those of other illnesses such as chickenpox (caused by the varicella virus), or sexually transmitted infections such as herpes or syphilis if the rash or lesions appear in the genital or anal region. 

The ongoing  global outbreak has shown that mpox can also present with few lesions, and asymptomatic infection can occur.​ The contribution of pre- and asymptomatic infection to transmission remains poorly understood. 


Public health response

WHO Response:

WHO maintains global mpox surveillance and continues to provide response guidance and support for all countries, including access to diagnostics and vaccines through multi-partner coordination including through the Access and Allocation Mechanism for mpox. WHO and partners are establishing the longer-term International Coordinating Group for mpox vaccine provision (ICG) to further accelerate timely outbreak response and ensure sustainable support for the future. Furthermore, WHO continues to evaluate available rapid diagnostic tests for field use.


Response measures in the United Kingdom:

The United Kingdom Health Security Agency (UKHSA) continues to work closely with the National Health Service England, public health agencies in Scotland, Wales and Northern Ireland, and is monitoring the situation in the United Kingdom and undertaking public health actions in accordance with the Mpox control: UK strategy 2025 to 2026 .

Public health information was made available to health care providers and the public. Contact tracing was completed in line with national guidance. Contacts were given appropriate health advice, offered vaccination, and monitored for symptoms.

All suspected mpox cases in the UK are tested using Orthopoxvirus-generic, MPXV-generic, and MPXV-specific PCR as primary testing, with clade differentiation assays performed on any positive samples. All samples identified as clade Ib, and selected samples identified as clade IIb cases undergo whole genome sequencing through Illumina-based workflows.


Response measures in India:

Public health measures, including contact tracing and monitoring, were implemented to prevent onward transmission. No secondary case was detected.

All suspected mpox cases in India are tested using Orthopoxvirus‑generic and MPXV‑specific PCR with clade differentiation assays. Positive cases undergo whole genome sequencing through Illumina‑based workflows.


WHO risk assessment

Mpox outbreaks must be considered in their local context, with meaningful involvement of affected communities, to ensure an in-depth understanding of the epidemiology, modes of transmission, risk factors for severe disease, viral reservoir and evolution, and relevance of strategic approaches and countermeasures for prevention and control.   

Multiple strains of MPXV are circulating through interconnected sexual networks across many countries and settings. Co-infection with different strains, that could lead to emergence of recombinant virus strains, while rare, can be expected. The case in India was infected with the same recombinant Ib/IIb MPXV strain detected in the United Kingdom. 

Symptom onset in the case reported in India occurred more than two months earlier than the case in the United Kingdom, and the great degree of similarity between their sequences suggests a common evolutionary history. This information has two important implications: i) the origin of the recombinant strain remains unknown; and ii) transmission of this recombinant virus already involves at least four countries in three WHO regions, and is therefore likely to be more widespread than currently documented.

For the cases in the United Kingdom and India, the initial clade differentiation PCR results indicated clade Ib and IIb MPXV, respectively. Thus, clade differentiation PCR assays alone may not reliably identify recombinant MPXV strains, and genomic sequencing is likely to be required for their detection.   

Due to the small number of cases found to date, conclusions about transmissibility or clinical characterization of mpox due to recombinant strains would be premature, and it remains essential to maintain vigilance regarding this development.

In light of the limited information available on this recombinant MPXV strain, the overall WHO public health risk assessment for mpox remains unchanged: the risk is assessed as moderate for men who have sex with men with new and/or multiple partners and for sex workers or others with multiple casual sexual partners, and low for the general population without specific risk factors.

All countries should remain alert to the possibility of MPXV genetic recombination. The public health risk posed by any newly detected recombinant strain should be assessed on a case-by-case basis, considering available epidemiological, clinical and genomic information.


WHO advice

Based on the information available, WHO recommends maintaining epidemiological surveillance, laboratory and genomic sequencing capacity for mpox, case management, infection prevention and control (IPC) measures, vaccination for people at risk, locally relevant risk communication and community engagement, and public health guidance for mpox.   

All recommendations are made in the context of ongoing transmission of clades Ib and IIb MPXV in key populations at risk in all WHO regions, including undetected or pre- and asymptomatic infections, as well as unreported cases. They additionally apply to settings where clades Ia and IIa MPXV continue to spread through a mix of zoonotic and human-to-human contact. There is likely to be wider circulation of this emerging recombinant strain of MPXV since at least September 2025 than reflected by the two cases documented and linked to four countries in three WHO regions. 


WHO advises Member States to:  

- maintain mpox surveillance and rapid reporting, including prompt IHR notification of any unusual events and imported cases in line with the WHO Standing Recommendations issued under the IHR (2005) and extended to August 2026; 

- continue to carry out genomic sequencing of all laboratory specimens from confirmed cases in early outbreak settings, and a representative sample of at least 10% of laboratory specimens from confirmed cases in settings experiencing community transmission, as per WHO guidance;  

- carry out targeted sample characterization for specific situations of interest, especially for cases who report recent travel to locations with clade I MPXV circulation or to locations which provide opportunities for sex tourism, prioritizing sequencing for cases in key populations at risk and for imported, unusual, or severe cases, and sharing sequences rapidly in public databases;  

- ensure quality case management and robust IPC practices and strengthen vaccination strategies, including ensuring access to mpox vaccines for key populations at risk;  

- continue to advance integration of HIV/STI and mpox health services to ensure early HIV testing and care for any person with suspected or confirmed mpox and rapid initiation or resumption of antiretroviral therapy in people living with HIV as needed for any person with mpox; 

- strive to eliminate human-to-human transmission of mpox where MPXV circulation remains low and ensure the maintenance of capacity for prompt outbreak response;  

- continue to provide information to travelers who may be at risk.

WHO recommends that no restrictions be applied for travel to, or trade with, the countries named in this report, based on the information available on the event reported here.  


Further information

1) World Health Organization. Mpox: fact sheet. 26 August 2024. Available from: http://www.who.int/news-room/fact-sheets/detail/monkeypox 

2) World Health Organization. Global mpox trends. Available from: https://worldhealthorg.shinyapps.io/mpx_global/ 

3) World Health Organization. Multi-country outbreak of mpox: external situation report no. 62. 23 January 2026. Available from: Multi-country outbreak of mpox, External situation report #62

4) World Health Organization. Fifth meeting of the International Health Regulations (2005) Emergency Committee regarding the upsurge of mpox 2024. 30 October 2025. Available from: https://www.who.int/news/item/30-10-2025-fifth-meeting-of-the-international-health-regulations-(2005)-emergency-committee-regarding-the-upsurge-of-mpox-2024

5) World Health Organization. Standing recommendations for mpox issued by the Director-General of the World Health Organization in accordance with the International Health Regulations (2005). 21 August 2023. Available from: https://www.who.int/publications/m/item/standing-recommendations-for-mpox-issued-by-the-director-general-of-the-world-health-organization-(who)-in-accordance-with-the-international-health-regulations-(2005)-(ihr) 

6) World Health Organization. Extension of standing recommendations for mpox to August 2026, by the Director-General of WHO. 21 August 2025. Available from: https://www.who.int/publications/m/item/extension-of-standing-recommendations-for-mpox-by-the-director-general-of-who 

7) World Health Organization. Clinical management and infection prevention and control for mpox: living guideline. May 2025. Available from: https://www.who.int/publications/i/item/B09434 

8) World Health Organization. WHO recommends rapid treatment initiation for people living with HIV and mpox. 16 July 2025. Available from: https://www.who.int/news/item/16-07-2025-who-recommends-rapid-treatment-initiation-for-people-living-with-hiv-and-mpox 

9) World Health Organization. WHO mpox multi-country rapid risk assessment, version 5. 13 October 2025. Available from: https://www.who.int/publications/m/item/who-rapid-risk-assessment---mpox--global-v.5 

10) World Health Organization. Strategic framework for enhancing prevention and control of mpox (2024–2027). 24 May 2024. Available from: https://www.who.int/publications/i/item/9789240092907 

11) World Health Organization. Guidance on use of Smallpox and mpox vaccines, including WHO Position paper on mpox vaccines and other resources to support countries. 23 August 2024 https://www.who.int/teams/immunization-vaccines-and-biologicals/diseases/smallpox-and-mpox  

12) World Health Organization. Frequently Asked Questions (FAQ) on use of fractional dosing with intradermal administration of mpox MVA-BN vaccine in the context of vaccine supply-constrained outbreak response. 19 June 2025. https://www.who.int/publications/m/item/frequently-asked-questions-(faq)-on-use-of-fractional-dosing-with-intradermal-administration-of-mpox-mva-bn-vaccine-in-the-context-of-vaccine-supply-constrained-outbreak-response  

13) World Health Organization. LC16m8 (live-attenuated freeze-dried vaccinia) smallpox and mpox vaccine. Interim guidance. 22 April 2025. Available from:  https://iris.who.int/server/api/core/bitstreams/9b10eb01-fbfd-4f9f-81b7-9c29ddbcc560/content

14) World Health Organization. Prequalification of Smallpox and Mpox vaccine (Live Modified Vaccinia Virus Ankara), 2024 September 13. Available from:  https://extranet.who.int/prequal/vaccines/p/imvanexr

15) World Health Organization. Emergency use listing of LC16m8. 2024 November 19. Available from: https://extranet.who.int/prequal/vaccines/lc16-kmb

16) UK Health Security Agency, Institute of Ecology and Evolution, University of Edinburgh; Inter-clade recombinant mpox virus detected in England in a traveller recently returned from Asia. 7 December 2025: https://virological.org/t/inter-clade-recombinant-mpox-virus-detected-in-england-in-a-traveller-recently-returned-from-asia/1015  

17) UK Health Security Agency, Mpox outbreak: epidemiological overview. 11 December 2025: https://www.gov.uk/government/publications/monkeypox-outbreak-epidemiological-overview/mpox-outbreak-epidemiological-overview-11-december-2025   

Source: 


Link: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON595

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Wednesday, February 11, 2026

#Transmission of #Mpox Virus from fire-footed rope #squirrels to sooty #mangabeys

 


Abstract

Mpox, caused by the monkeypox virus (MPXV; Orthopoxvirus monkeypox), is on the rise in West and Central Africa. African rodents, especially squirrels, are suspected to be involved in MPXV emergence, but no evidence of a direct transmission to humans or non-human primates has been established. Here we describe an outbreak of MPXV in a group of wild sooty mangabeys (Cercocebus atys) in TaĂ¯ National Park (CĂ´te d’Ivoire). The outbreak affected one-third of the group, killing four infants. To track its origin, we analysed rodents and wildlife carcasses from the region. We identified a MPXV-infected fire-footed rope squirrel (Funisciurus pyrropus), found dead 3 km from the mangabey territory 12 weeks before the outbreak. MPXV genomes from the squirrel and the mangabey were nearly identical. A video record from 2014 showed a mangabey from this group eating the same squirrel species and diet metabarcoding of faecal samples collected from mangabeys before the outbreak identified two samples containing fire-footed rope squirrel DNA. One of these samples was also the first positive for MPXV. This represents a rare case of direct detection of interspecies transmission. Our findings indicate that rope squirrels were the source of the MPXV outbreak in mangabeys. Because squirrels and non-human primates are hunted, traded and consumed by humans in West and Central Africa10,11, exposure to these animals probably represents risk for zoonotic transmission of MPXV.

Source: 


Link: https://www.nature.com/articles/s41586-025-10086-y

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Friday, January 23, 2026

#Mpox Multi-country external #situation #report no. 62, published 23 January 2026 (#WHO, summary)

 


Highlights

All clades of monkeypox virus (MPXV) continue to circulate. 

- Unless mpox outbreaks are rapidly contained and human-to-human transmission is interrupted, there is a risk of sustained community transmission.  

• At the time of reporting, data from the WHO European Region for December 2025 had not yet been submitted; therefore, the information presented below does not include the European Region

In December 2025, 31 countries across five WHO regions (European Region excluded) reported a total of 1040 new confirmed mpox cases, including six deaths (case fatality ratio [CFR] 0.6%). 

- Of these cases, 78% were reported in the African Region

- Four regions observed a decline in confirmed cases in December, compared to November 2025, while the Eastern Mediterranean Region reported more cases than the previous month.     

Fifteen countries in Africa reported active transmission of mpox in the last six weeks (7 December 2025 – 18 January 2026), with 871 confirmed cases, including five deaths (CFR 0.6%). 

- Countries reporting the highest number of cases in this period are the Democratic Republic of the Congo, Guinea, Madagascar, Liberia and Ghana

Four countries, Czechia, Israel, Madagascar and Nepal, and the territory of Mayotte, France, have reported mpox due to clade Ib MPXV for the first time.   

Outside Africa, community transmission of clade Ib MPXV continues to be reported in France, Italy and Spain

- Investigations are ongoing for the case reported in Czechia.  

Madagascar is reporting an active mpox outbreak, which began in early December 2025 among individuals without recent travel and quickly expanded across the country, which currently is experiencing community transmission of clade Ib MPXV.  

WHO published ‘Analytical considerations for genomic surveillance of mpox virus’, outlining key considerations for implementing MPXV genomic surveillance, bringing together available evidence and expert input to support the use of pathogen genomics in public health surveillance and response.  

The report also includes a phylogenetic analysis of MPXV sequences shared on open-source platforms, highlighting the main genetically distinct strains detected in each country since 2022. 

WHO published the mpox global donor report on 21 January 2026, summarizing donor contributions and funding allocations during the PHEIC period of the mpox response (August 2024– September 2025) across key response priorities 

On 22 January 2026, the Africa Centres for Disease Control and Prevention lifted the declaration of a Public Health Emergency of Continental Security for mpox.  

Source: 


Link: https://www.who.int/publications/m/item/multi-country-outbreak-of-mpox--external-situation-report--62---23-january-2026

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Saturday, January 3, 2026

The Emerging #Threat of #Monkeypox: An Updated #Overview



Abstract

Monkeypox (MPOX) is an emerging zoonotic disease caused by monkeypox virus (MPXV), an orthopoxvirus closely related to smallpox. Initially confined to endemic regions in Central and West Africa, MPOX has recently gained global significance with outbreaks reported across multiple continents. MPXV is maintained in animal reservoirs but is increasingly transmitted from person to person, facilitated by close contact, respiratory droplets, and, in some cases, sexual transmission. Clinically, MPOX presents with fever, lymphadenopathy, and a characteristic vesiculopustular rash, though atypical manifestations have been observed in recent outbreaks, complicating diagnosis. Laboratory confirmation relies on molecular testing, while differential diagnosis must consider varicella, herpes, and other vesicular illnesses. Therapeutic options remain limited; supportive care is the cornerstone of management, but antivirals such as tecovirimat and brincidofovir, as well as smallpox vaccines, have shown efficacy in mitigating disease severity and preventing infection. The unprecedented global outbreak has underscored the importance of surveillance, rapid diagnostics, and coordinated public health responses to contain transmission. This review provides an overview of epidemiology, virology, clinical manifestations, modes of transmission, available diagnostics, and prophylactic and therapeutic strategies against MPOX. We also discuss the role of animal reservoirs, viral evolution, and human-to-human transmission in shaping the dynamics of recent MPOX outbreaks. By summarizing the latest evidence, this review aims to inform clinicians, researchers, and policymakers about key aspects of MPOX biology, clinical management, and prevention, while identifying gaps that warrant future investigation for the control of this and potentially other emerging zoonotic-related pathogens with an impact on human health.

Source: 


Link: https://www.mdpi.com/1999-4915/18/1/69

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Wednesday, December 31, 2025

A cocktail #vaccine with #monkeypox virus #antigens confers protection without selecting #mutations in potential immune evasion genes in the vaccinia WR strain challenge


ABSTRACT

Faced with the global monkeypox outbreak, current vaccine development predominantly focuses on the mRNA platform despite its limitations in stability and long-term efficacy. Here, we engineered a recombinant vesicular stomatitis virus (rVSV)-vectored cocktail vaccine encoding four conserved monkeypox virus (MPXV) antigens (A35R, A29L, M1R, and B6R; >94% clade homology), leveraging the thermostable properties of the VSV platform validated for 4°C storage in Ebola vaccines. In BALB/c mice, this multi-antigen vaccine elicited a rapid humoral response with specific IgG detectable by day 7, effectively neutralized the virus, and induced a robust Th1/Th2 balanced cytokine response. Immunization conferred 100% survival against lethal vaccinia virus WR strain challenge, with undetectable viral loads in the lungs and serum, and sustained efficacy against secondary infection at 60 days. Histopathology confirmed minimal lung damage in vaccinated mice. Crucially, upon the successive challenges, mutations in key poxvirus immune evasion genes (E3L and B7R) emerged in the single-component vaccine groups but were absent in the cocktail vaccine group. This finding provides direct evidence that the cocktail strategy suppresses viral escape, underscoring a fundamental advantage over single-antigen approaches. Our findings demonstrate the rVSV-based cocktail vaccines as a potent, scalable, and thermostable candidate for global MPXV control, particularly in regions with limited settings.


IMPORTANCE

The global emergence of the monkeypox virus (MPXV) underscores the urgent need for effective and accessible vaccines. We developed a recombinant vesicular stomatitis virus (rVSV)-vectored cocktail vaccine expressing four conserved MPXV antigens. This multivalent vaccine elicits rapid and potent immune responses in mice, conferring complete protection against lethal vaccinia virus challenge. A critical finding is that while successive viral challenges selected for mutations in key immune evasion proteins in single-antigen vaccine groups, these mutations were absent in the cocktail-vaccinated group. This suggests that the cocktail strategy may suppress viral genetic drift, potentially limiting escape pathways. Combined with the thermostability of the VSV platform, our vaccine presents a promising and scalable candidate for combating monkeypox.

Source: 


Link: https://journals.asm.org/doi/full/10.1128/mbio.03200-25?af=R

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Thursday, December 18, 2025

The #epidemiology of #pathogens with #pandemic potential: A review of key #parameters and clustering analysis

 


Highlights

• Epidemiological parameters differ by pathogen and by setting.

• Unsupervised machine learning classifies pathogens into distinct epidemiological archetypes.

• Pathogens can be allocated into defined groups outlining plausible parameter ranges across epidemiologically similar pathogens.


Abstract

Introduction

In the light of the COVID-19 pandemic many countries are trying to widen their pandemic planning from its traditional focus on influenza. However, it is impossible to draw up detailed plans for every pathogen with epidemic potential. We set out to try to simplify this process by reviewing the epidemiology of a range of pathogens with pandemic potential and seeing whether they fall into groups with shared epidemiological traits.

Methods

We reviewed the epidemiological characteristics of 19 different pathogens with pandemic potential (those on the WHO priority list of pathogens, different strains of influenza and Mpox). We extracted data on key parameters (reproduction number serial interval, proportion of presymptomatic transmission, case fatality risk and transmission route) and applied an unsupervised learning algorithm. This combined Monte Carlo sampling with ensemble clustering to classify pathogens into distinct epidemiological archetypes based on their shared characteristics.

Results

From 154 articles we extracted 302 epidemiological parameter estimates. The clustering algorithms categorise these pathogens into six archetypes (1) highly transmissible Coronaviruses, (2) moderately transmissible Coronaviruses, (3) high-severity contact and zoonotic pathogens, (4) Influenza viruses (5) MERS-CoV-like and (6) MPV-like.

Conclusion

Unsupervised learning on epidemiological data can be used to define distinct pathogen archetypes. This method offers a valuable framework to allocate emerging and novel pathogens into defined groups to evaluate common approaches for their control.

Source: 


Link: https://www.sciencedirect.com/science/article/pii/S1755436525000702?via%3Dihub

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Saturday, November 8, 2025

Long-term consequences of #monkeypox virus #infection or modified vaccinia virus Ankara #vaccination in #Belgium ...

 


Summary

Background

Given the continued global circulation of monkeypox virus (MPXV), we aimed to assess the long-term clinical consequences of MPXV infection and the continued presence of the virus in saliva, semen, and the anorectum. We also aimed to compare long-term antibody dynamics after MPXV infection with modified vaccinia Ankara–Bavarian Nordic (MVA-BN) vaccination.

Methods

In this mixed retrospective and prospective cohort study, adults with acute MPXV infection at the Institute of Tropical Medicine (Antwerp, Belgium) were enrolled in a clinical registry (MPX-COHORT) from May 13, 2022, with follow-up at 1 month after infection. On Oct 3, 2022, we initiated a long-term follow-up study (POQS-FU-PLUS) to extend follow-up of people with mpox and to establish a parallel cohort of adults who received MVA-BN vaccination between Aug 3, 2022, and Jan 4, 2023. Participants were eligible for the second cohort if they received two doses of MVA-BN, unless they had previous smallpox vaccination, in which case one dose of MVA-BN sufficed. POQS-FU-PLUS visits were prospectively scheduled 8, 16, and 24 months after infection or vaccination. During these visits, participants with mpox underwent physical and mental health assessments and provided saliva, anorectal swabs, and serum and optionally semen (at month 8 only); people vaccinated with MVA-BN provided serum only. Missing serum samples were supplemented by biobanked serum samples collected during routine clinic visits within the same timeframe, as were serum samples predating MPXV infection and MVA-BN vaccination. Saliva, anorectal swabs, and semen were tested by MPXV PCR, and serum samples were tested for vaccinia virus (VACV) lysate, MPXV-E8L binding, and MPXV neutralising antibodies. Results were compared between people with MPXV infections and MVA-BN vaccination, taking into account childhood smallpox vaccination. The main outcomes were the in-depth clinical description of people with mpox, including complications, the long-term physical and mental health consequences of mpox, and antibody concentrations 8 months after MPXV infection and MVA-BN vaccination.

Findings

Of 250 individuals with MPXV infection, 237 were enrolled (199 prospectively and 38 retrospectively). Of 1728 people with MVA-BN vaccines, 210 were enrolled (209 prospectively and one retrospectively). Of people with MPXV infection, 112 (47%) of 237 attended follow-up at 8 months, 134 (57%) at 16 months, and 63 (27%) at 24 months. For people vaccinated with MVA-BN, 205 (98%) of 210 attended follow-up at 8 months, 161 (77%) at 16 months, and 144 (69%) at 24 months. The median age of all participants was 40 years (IQR 33–48). The majority (425 [96%] of 443) identified as men. Scarring occurred in 33 (46%) of 71 patients with mpox at month 8, 17 (30%) of 57 at month 16, and 20 (32%) of 63 at month 24. Other symptoms largely resolved within a year. All saliva and anorectal MPXV PCR were negative at follow-up (69 swabs were collected at 8 months, 51 at 16 months, and 63 at 24 months; upper 95% CI 5%, 7%, and 6% respectively); semen MPXV PCR at month 8 was negative for all 23 swabs (upper 95% CI 15%). At month 8, among participants not vaccinated against smallpox during childhood, MVA-BN induced lower binding antibody concentrations than MPXV infection (0·39 fold-change, 95% CI 0·25–0·62, p<0·0001 for VACV antibodies; 0·60 fold-change, 95% CI 0·46–0·79, p=0·0017 for MPXV-E8L antibodies); MPXV neutralising antibodies were detected in only 4% (95% CI 1–17%) of people with MVA-BN vaccines; and intradermal vaccination elicited lower binding antibody concentrations than subcutaneous vaccination (0·26 fold-change, 95% CI 0·17–0·39, p<0·0001 for VACV antibodies; 0·54 fold-change, 95% CI 0·37–0·77, p=0·0009 for MPXV-E8L antibodies).

Interpretation

Individuals previously infected with MPXV show strong and durable immunological memory lasting up to 2 years after infection, in contrast to the less robust and shorter-lived response observed after MVA-BN vaccination. These findings suggest that MPXV infection confers long-term protection against reinfection, whereas vaccine-induced immunity can wane over time and requires boosting. Further studies are needed to determine whether booster doses can enhance the durability of immunological memory in previously vaccinated individuals. Should booster vaccination prove beneficial, targeted revaccination campaigns will be necessary to maintain population-level protection.

Funding

Research Foundation–Flanders; Department of Economy, Science and Innovation Flanders; and Netherlands Organization for Health Research and Development.

Source: The Lancet Infectious Diseases, https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(25)00545-6/fulltext?rss=yes

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Tuesday, October 28, 2025

Latest #update on Clade Ib #mpox - #UKHSA reminds eligible groups to come forward for mpox #vaccination.

 


Last updated 27 October 2025


Latest update

UKHSA is aware of small numbers of locally-acquired cases of clade Ib mpox in the USA, Spain, Italy, the Netherlands and Portugal which have no connection to countries with known clade Ib mpox transmission.  

This suggests there is now community transmission of clade Ib mpox globally. Most of the new cases identified in Europe and the USA have been in gay, bisexual and other men who have sex with men, a population in which clade Ib mpox transmission has not previously been observed.  

Mpox is usually a mild infection, and clade Ia and Ib mpox are no longer classified as a high-consequence infectious disease (HCID). However, it can be severe in some cases. 

The UK has a routine mpox vaccination programme in place for eligible groups, including those who:  

-- have multiple sexual partners  

-- have group sex  

-- visit sex-on-premises venues  

Studies show that the vaccine is around 75 to 80% effective in protecting people against clade II mpox. Although there are no studies on vaccine effectiveness against clade Ib mpox, vaccine protection is expected. A high proportion of people in eligible groups in the UK have already had the vaccine.  

To check if you are eligible or to book an appointment, visit Mpox vaccine - NHS.   

Common symptoms of mpox include: 

-- a skin rash or 

-- pus-filled lesions which can last 2 to 4 weeks. 

-- It can also cause fever, headaches, muscle aches, back pain, low energy and swollen lymph nodes.  

Dr Katy Sinka, Head of Sexually Transmitted Infections at UKHSA:  

''The ways in which we are seeing mpox continue to spread globally is a reminder to come forward for the vaccine, if you are eligible.  

''Although mpox infection is mild for many, it can be severe.  

''Getting vaccinated is a proven effective way to protect yourself against severe disease, so please make sure to get the jab if you are eligible.  

''It is important to remain alert to the risks from this unpleasant illness. Anyone who thinks they may have mpox should contact NHS 111 for advice on what to do.

UKHSA has robust mechanisms in place to investigate suspected cases of mpox of all clade types, irrespective of travel history, with regular updates on confirmed UK cases of mpox.  

UKHSA has today published a technical assessment on mpox to reflect the latest epidemiology. 

Further information about symptoms is available on the NHS website.  

Dr Will Nutland, Director at The Love Tank said:  

''Mpox hasn’t been making headlines for more than a year but these cases show that mpox has not gone away. Routine availability of mpox vaccination, through NHS sexual health clinics, provides an effective way of protecting against mpox. The Love Tank continues to work alongside NHS colleagues to ensure that vaccination programmes continue to reach those who most need them, including in community settings.

Prof. Matt Phillips, President of the British Association for Sexual Health and HIV said:  

''We encourage anyone who is eligible for the vaccine against mpox to talk to their local sexual health clinic and arrange to be vaccinated.   

''These cases are a reminder both that mpox has not gone away, and of the importance of vaccine programmes in reducing the impact of mpox infection.

Richard Angell OBE, Chief Executive, Terrence Higgins Trust said: 

''The last outbreak of mpox hit the gay, bi and other men who have sex with men community disproportionately hard. While it is described as ‘mild’, those who have the mpox rash around their face and body, including in intimate and sensitive areas, will tell you how unpleasant and painful it is.  

''In 2022, we were not prepared for the MPOX outbreak and the tools available were hard to mobilise – this time we have a government-funded vaccine programme available to gay and bi men and it is strongly encouraged for those who have multiple partners, take part in sex parties or visit sex on premises venues.  

''With Winter Pride season soon upon us across Europe, those travelling to these events would be wise to get vaccinated, at least once, if not twice. Those who have had 2 mpox jabs should have protection. Anyone experiencing a rash after sex should seek out a sexual health clinic or call THT Direct on 0808 802 1221.

(...)

Source: United Kingdom Health Security Agency, https://www.gov.uk/government/news/ukhsa-detects-first-case-of-clade-ib-mpox

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Tuesday, August 12, 2025

#Mpox: disease #manifestations and therapeutic #development

 


ABSTRACT

Mpox, caused by monkeypox virus (MPXV) infection, has emerged as a significant global health threat. The World Health Organization (WHO) has twice declared a Public Health Emergency of International Concern for mpox: first for the 2022–2023 global outbreak and subsequently for concurrent outbreaks in Africa. Beyond MPXV, other members of the Orthopoxvirus genus also pose growing risks of zoonotic spillover, with the potential to jump from animal reservoirs to humans. Clinically, mpox is distinguished from other Orthopoxvirus infections by its propensity to cause severe systemic manifestations alongside localized skin lesions, disproportionately affecting vulnerable groups such as children, pregnant women, and immunocompromised individuals. Although vaccines are available, effective therapeutics are equally essential in combating the mpox crisis. Current antiviral agents, including tecovirimat and brincidofovir, have demonstrated uncertain or disappointing efficacy in preclinical and clinical studies, underscoring the urgent need for further therapeutic development. This review provides a concise synthesis of recent advances in understanding mpox epidemiology and clinical features and offers an in-depth discussion of the current status and future directions in therapeutic development. We highlight the importance of innovative experimental models that can authentically replicate mpox disease manifestations and serve as robust platforms for therapeutic testing. Advancing these research efforts is critical for responding to the ongoing mpox emergency and for sustaining preparedness against future poxvirus epidemics.

Source: Journal of Virology, https://journals.asm.org/doi/full/10.1128/jvi.00152-25?af=R

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Sunday, August 10, 2025

A multivalent #mRNA #vaccine elicits robust immune responses and confers #protection in a murine #model of #monkeypox virus infection



Abstract

Monkeypox virus (MPXV) has re-emerged globally since May 2022, posing a significant public health threat. To address this, we develop two multivalent mRNA vaccine candidates—AAL, encoding three MPXV antigens, and AALI, which combines AAL with an immune-enhancing IFN-α protein. Both vaccines are delivered via mannose-modified lipid nanoparticles to target dendritic cells. Here we show that these vaccines elicit strong antibody responses against vaccinia virus and multiple MPXV clades, induce robust memory B-cell and T-cell responses, and promote dendritic cell maturation. In mouse challenge models, both vaccines provide protection against clade IIb MPXV and vaccinia virus, significantly reducing viral loads and preventing lung damage. Immune profiling reveals enhanced B- and T-cell receptor diversity and distinct CDR3 motifs post-vaccination. These findings demonstrate the potential of using mRNA-based multivalent vaccines as an effective strategy for preventing mpox and related Orthopoxvirus infections.

Source: Nature Communications, https://www.nature.com/articles/s41467-025-61699-w

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