Impaired #Neuraminidase and Polymerase Activities Correspond With Limited Aerosol Infectivity of #B3.13 and #D1.1 #H5N1 Lineages in #Human Respiratory Cultures

 

Abstract

The ongoing panzootic of clade 2.3.4.4b highly pathogenic avian influenza (HPAI) H5N1 viruses has reached a critical point, marked by unprecedented mammalian spillover and sustained outbreaks in U.S. dairy cattle. While these viruses remain highly lethal in traditional ferret models, human infections-primarily linked to the B3.13 and D1.1 lineages-have been notably mild, typically presenting as conjunctivitis with minimal respiratory involvement. In this study, we address this disconnect by evaluating the infectivity of recent H5N1 isolates using a physiologically relevant air-liquid interface (ALI) culture system that incorporates an aerosol settling chamber. We demonstrate that while direct liquid inoculation leads to efficient replication, aerosolized H5N1 strains exhibit a significant defect in their ability to infect human respiratory epithelium. In contrast, a prototypic H5N1 virus remains highly pathogenic and lethal in ferrets regardless of the inoculation route, showing systemic dissemination to the brain and other organs. Our findings identify two primary viral determinants driving this respiratory restriction: reduced neuraminidase (NA) enzymatic activity and impaired polymerase activity. Collectively, these results suggest that commonly used mammalian models may overstate current human pandemic risk. This work highlights the critical need for alternative risk-assessment platforms to identify the specific genetic shifts required for these viruses to overcome existing barriers to human adaptation.

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.08.18.745466v1

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2nd meeting of #IHR EC on the #epidemic of #Ebola Bundibugyo virus disease in #DRC – Temporary #recommendations (WHO, August 25 '26)

 

On 18 August 2026, the Emergency Committee regarding the epidemic of Ebola Bundibugyo virus disease in the Democratic Republic of the Congo met for the second time to reassess the situation, in line with International Health Regulations (2005).

    The Director-General, considering the advice of the Committee, issued the following updated temporary recommendations for States Parties. The recommendations for the Democratic Republic of the Congo provide more detailed guidance on surveillance, case detection and investigation, infection prevention and control, clinical care, risk communication and community engagement than those previously issued, and include a new section on social measures, mass gatherings and domestic mobility.

Temporary recommendations

    These temporary recommendations are issued by the Director-General of WHO for subsets of States Parties according to the public health risk associated with the Bundibugyo virus disease (BVD) epidemic they face.

    All current WHO interim technical guidance can be accessed on this page of the WHO website. WHO evidence-based guidance has been and will continue to be updated in line with the evolving situation, updated scientific evidence, and WHO risk assessment.

    The implementation of these temporary recommendations by States Parties shall be with full respect for the dignity, human rights and fundamental freedoms of persons, in accordance with the principles set out in Article 3 of the IHR.

    Note: The text in backets next to each temporary recommendation indicates the status with respect to the set of temporary recommendations issued on 22 May 2026.

For States Parties with community transmission of Bundibugyo virus (Democratic Republic of the Congo) [Modified]

    As of 14 August 2026, the WHO Secretariat assessed the risk for these States Parties as “Very high”. 

    At the time these temporary recommendations are issued, only the Democratic Republic of the Congo falls in this group. [Modified]

    The epidemic is caused by BDBV, a virus belonging to the Orthoebolavirus genus. Unlike Ebola virus causing Ebola virus disease, although clinical trials are ongoing, there are no currently approved therapeutics or vaccines against BDBV. Should effective BVD-specific vaccines and therapeutics become available, based on experience from the 2013–2016 Ebola virus disease epidemic in West Africa, they are likely to have a complimentary effect on transmission and mortality, but they will not be a substitute for effective, core public health interventions. [Modified]

Coordination and high-level engagement

    ° Declare, or maintain, the BDBV epidemic a health emergency, at national or sub-national level, in accordance with domestic laws, and as appropriate. [Extended with rephrasing]

    ° Scale-up national disaster or health emergency management mechanisms, including an activated emergency operation centre, under the authority of the Head of State or relevant government authority, to coordinate response and preparedness activities across Government sectors, administrative levels, and partners. [Modified]

    ° Establish, and maintain up to date, a single national plan (e.g., action plan, response plan) to guide response efforts, across Government sectors and partners, reflecting the role and responsibilities of Government entities and all partners involved in the response, to ensure efficient and effective implementation and monitoring of comprehensive BVD control measures. 

    ° These measures must include: [New, resulting from splitting of temporary recommendation previously under “Coordination and high-level engagement]

        § community protection, including risk communication and community engagement;

        § enhanced surveillance and case identification;

        § contact tracing;

        § laboratory diagnostic testing;

        § infection prevention and control (IPC);

        § case management;

        § safe and dignified burials;

        § continuity of essential health services;

        § logistics; and

        § health workforce management and protection, including timely payment of salaries and, as appropriate, hazard pay.

[Modified]

    ° Negotiate, as applicable, and establish security corridors, including cross-border, to allow responders to safely reach affected communities, including in IDP camps and other humanitarian settings, as well as to allow communities to seek appropriate health care. [Extended]

    ° Establish immigration procedures to allow timely and fluid influx and outflux of international responders both, to cater for identified response needs and to allow for their rotation. [New]

    ° Establish customs clearance procedures, as well as other administrative and regulatory ones, to expedite the importation of supplies needed to sustain the response [New]

    § Notify WHO, through the relevant WHO IHR Contact Point in the WHO Regional Office, of the detection of suspected, probable and confirmed BVD cases on a daily basis, as per WHO case definitions available here. [Extended]

Risk communication and community engagement

    ° Integrate, at the lowest level designated to coordinate response activities, the implementation of risk communication and community engagement interventions (community networks, workforce capacity, community intelligence and feedback systems, and accountability processes). [New]

    ° Scale up trust-building and community engagement through trusted communication channels and local actors, including local leaders, religious leaders, traditional healers and survivors, to support community participation in fostering the acceptance of public health measures, including early detection, case referral, contact tracing, safe and dignified burial practices, and adoption of protective behaviours. [Extended with rephrasing, including merging of one temporary recommendation previously under “Risk communication and community engagement”]

    ° Strengthen community awareness, engagement and participation, to establish and strengthen trust, by identifying and addressing cultural norms and beliefs that may serve as barriers to their full participation in the response; and by integrating interventions and community feedback, within the wider response, to address the needs of the population, particularly in contexts of the protracted humanitarian crisis in the Eastern provinces of the Democratic Republic of Congo. [Extended]

    ° Activate and train local networks, including community health workers, Red Cross volunteers, and other trusted community actors to promote protective behaviours; facilitate early detection and referral of suspected BVD cases; support contact tracing activities; and collect and relay community feedback to enhance the acceptance of public health measures. [Extended with rephrasing]

    ° Enable adherence to movement restrictions, associated with the application of control measures, by providing food, water, communication, financial and psychosocial support. [Extended]

Surveillance and laboratory

    ° Establish and maintain up to date a register of signals consistent with BVD (“alerts”, e.g., including for clusters of unexplained illness or deaths), including status of their investigation. [Extended with rephrasing, previously under “Coordination and high-level engagement”]

    ° Establish and maintain an up to date a line list of suspected cases, probable cases, and confirmed BVD cases, including a consolidated one at the national level, while building chains of transmission. [Extended, previously under “Coordination and high-level engagement”]

    ° Establish and maintain up to date the list of contacts of all confirmed and probable BVD cases, monitor, on a daily basis, each contact for 21 days after the date of last known exposure, and record their status. Both the evolution of the epidemic and resources available may require reiterative risk-based prioritization of contacts requiring identification and monitoring. [Extended with rephrasing, including merging of two temporary recommendations previously under “Coordination and high-level engagement” and “Surveillance and laboratory”]

    ° Establish a mechanism to monitor the evolution of indicators related to the performance of contact tracing activities. [Extended]

    ° Strengthen surveillance and laboratory capacity, decentralized across sub-national administrative levels (e.g., provinces and districts/health zones) with community BDV transmission, as well as in their neighbouring sub-national administrative levels, through: [Extended with rephrasing]

    ° dedicated surveillance and response teams within each health zone and in neighbouring health zones determined to be at high-risk for the introduction of BVD; [Extended]

    ° active case finding and enhanced community surveillance; [Modified]

    ° the investigation of “alerts” within 24 hours from detection; and [Extended]

    ° scale-up and strengthen decentralized RT-PCR laboratory capacities for quality, safe and timely testing for BDBV, including sample collection, rapid referral and transportation of samples and timely dissemination of laboratory test results; and train laboratory personnel accordingly. [Modified]

Safe and dignified burials

    ° Implement protocols, including for their recording and monitoring, in all areas with community BVD transmission, as well as neighbouring areas, ensuring funerals and burials are conducted by well-capacitated, -trained and appropriately PPE-equipped personnel, including safe handling and disinfection of the burial sites with provision made for the presence of the family and cultural practices, and in accordance with relevant national laws and regulations. [Extended with rephrasing]

    ° Investigate each death, occurring outside BVD isolation and treatment centers, to identify or link to BVD chains of transmission and to better understand the reasons underpinning the community’s reluctance to accept safe and dignified burials. [New]

Patient referral pathway and access to safe and optimized intensive care

    ° Establish dedicated BVD isolation and treatment centers or units for suspected,    probable, and confirmed BVD cases, located within, or close to, areas with community BVD transmission, with sufficient staff who are specifically trained and equipped to implement optimized intensive supportive care. [Extended]

    ° Establish protocols for early identification and transferring suspected BVD patients safely to dedicated health care facilities for their isolation, assessment and treatment in a humane and patient-centred approach. This includes trained ambulance teams, mechanisms to notify the receiving health care facility, the application of appropriate IPC precautions during transfer, and decontamination protocols for vehicles and equipment. [Extended with rephrasing]

    ° Establish protocols for the handling and disposal of medical waste, including segregation at point of generation, safe collection and storage, and decontamination by autoclaving or incineration prior to final disposal, in accordance with international guidance. [Modified]

    ° Establish survivor follow-up programmes, including counselling, psychosocial support and stigma-reduction programmes, clinical care, as well as sexual health advice, semen testing, and condoms as appropriate. [Extended]

    ° Maintain the provision of essential health services package – through implementing infection, prevention and control measures to protect healthcare workers –, and monitor any disruption thereof. This package of essential health services includes, at minimum, malaria diagnosis and treatment, and maternal and child health services. [Extended with rephrasing]

Infection prevention and control in health facilities and communities [Modified]

    ° Strengthen measures to prevent health-care associated infections (HAIs), including systematic mapping and assessment of public and private health facilities – that are not BVD isolation and treatment centers –, the establishment, dissemination and implementation of protocols for standards and transmission-based precautions, including screening, triage, isolation, targeted IPC interventions and sustained monitoring and supervision [Modified]

    ° Provide regularly scheduled IPC training to, and assessments of health workers supervision in their proper use of personal protective equipment (PPE) supported by designated IPC focal points at facility-level, and standardized supportive-supervision checklists (e.g. WHO IPC scorecard). [Modified]

    ° Provide health facilities with sufficient and uninterrupted supplies, including PPE, safe injection equipment, with monitoring of stock out rates. [Modified, including moving part of previous temporary recommendation under “Coordination and high-level engagement”]

    ° Establish channels for health workers to report and be assessed following exposures, and have access to psychosocial support and, when possible post-exposure prophylaxis under compassionate use or clinical trial. All BVD cases occurring among health workers must be investigated promptly to implement timely corrective actions within health facilities and mitigation measures as appropriate at the community level. [Extended with rephrasing]

    ° Build community IPC capacity by training community leaders and emphasizing that hand hygiene not only contributes to bringing the BVD epidemic under control but also reduces the risk of transmission of other communicable diseases present in the same areas. Hand hygiene shall be facilitated at critical spots, such as schools, churches, bars, markets, local gatherings sites, points of entry, etc. [Extended with rephrasing]

Social measures, mass-gathering events, and domestic mobility [New]

    ° Postpone mass gatherings in areas with ongoing community BDV transmission. For mass gathering events planned in other areas, the decision to hold them shall be based on event-specific risk assessment. [Modified, previously under “Border health, international travel and mass-gathering events”]

    ° Enact and implement measures reducing crowding in food and drink establishments and nightclubs. [New]

    ° Enact and implement measures limiting to one the number of passengers motorbikes. [New]

    ° Enact and implement measures for the safe opening of schools. [New]

    ° Establish 24/7 health check points along the roads connecting areas with community BVD transmission and areas determined to be at high-risk for the introduction of BVD, as informed by the analysis of population mobility patterns. [New]

    ° Establish BVD surveillance on vessels navigating inland waterways, connecting areas with community BVD transmission with major urban centers, including the Capital Kinshasa. [New]

International travel and border health [Modified]

    ° Establish arrangements with States Parties adjacent to areas experiencing community BVD transmission and characterised by substantial cross border movement and trade activities, to enhance surveillance at ground crossings and along bordering areas. This includes establishing coordination mechanisms for sharing of information regarding contacts who have, or may have, crossed the border, thus enabling continuity of follow-up; as well as the identification and follow up of contacts following the detection of a BVD case in the. [Extended with rephrasing]

    ° Implement measures, in accordance with national laws and regulations, to prevent suspected, probable, and confirmed BVD cases, as well as their contacts, based on the assessment of exposure, from undertaking international travel, unless the travel is part of an appropriate medical evacuation. [Extended]

    ° Prevent the cross-border movement of the human remains of deceased suspected, probable or confirmed BVD cases, unless authorized through bilateral arrangements. [Extended]

    ° Implement exit screening at all points of entry – airports, ports and ground crossings – consisting of, at a minimum, a questionnaire encompassing history of potential exposure to BVD, a temperature measurement and, in case of fever, an in-depth assessment of the risk of BVD, by personnel trained and adequately equipped with PPE. [Extended with rephrasing]

    ° Report to WHO, through the relevant WHO IHR Contact Point in the WHO Regional Office, the implementation of any international traffic related measure adopted. [Extended]

Operations, supplies and logistics

    ° Report to WHO, through the relevant WHO IHR Contact Point in the WHO Regional Office, the implementation of any international traffic related measure adopted. [Extended]

    ° Establish and maintain a timely, robust and monitored end-to-end emergency supply chain to ensure needs-based forecasting, procurement, importation, storage, transportation and distribution of all relevant commodities and countermeasures, including PPE, diagnostics, therapeutics, IPC materials, medical supplies and essential non-medical equipment, while ensuring visibility of stocks, pipelines, consumption and potential gaps. [New, replacing terminated temporary recommendation previously under “Operations, supplies and logistics”]

    ° Establish and coordinate the capacity to rapidly construct, rehabilitate, equip and maintain isolation and treatment facilities and other health infrastructure, ensuring their safe and functional operation in accordance with the standards and technical IPC and case management international guidance. [New, replacing terminated temporary recommendation previously under “Operations, supplies and logistics”]

    ° Establish, operationalize and steer a national health logistics partners coordination cell that provides shared visibility of needs, stocks and partner pipelines of relevant health products; identifies gaps, bottlenecks and duplications; and facilitates the prioritization and mobilization of logistics resources in line with national response priorities. [New, replacing terminated temporary recommendation previously under “Operations, supplies and logistics”]

Research and development of medical countermeasures

    ° Engage, when feasible, with research partners and international institutions to: [Extended]

        § define a robust laboratory strategy, urgently implement head-to-head comparison studies of PCR diagnostics to validate or invalidate the PCR platforms currently used in the field and other upcoming products. [Extended]

        § conduct in-depth investigations to identify and characterize BDBV transmission dynamics associated with specific settings, including related modes of BDBV transmission (e.g. caretaking at home, hospital, or at traditional healers, re-use of needles), as well as exposure to animal populations. [New]

        § implement ethically approved, scientifically robust clinical trials to advance the development and use of candidate therapeutics for treatment and post-exposure prophylaxis, as well as for candidate vaccines. [Extended]

        § establish, with a view to support research, expedited and efficient national regulatory and ethics reviews, community engagement, pharmacovigilance (where applicable), data sharing and equitable access arrangements. [Extended]

Reporting on the implementation of temporary recommendations

    ° Report to WHO, on a monthly basis, on the status of, and challenges related to, the implementation of these temporary recommendations, using a standardized tool and channels that will be made available by WHO, also allowing for the monitoring of progress and the identification of gaps in the national response. [Modified]

For States Parties with land borders adjoining States Parties with community BVD transmission [Modified]

    ° As of 14 August 2026, the WHO Secretariat assessed the regional risk “High”. 

    At the time these temporary recommendations are issued, these States Parties include Angola, Burundi, Central African Republic, Republic of Congo, Rwanda, South Sudan, Tanzania, Uganda and Zambia: [Modified]

        § Establish, or maintain, a national coordination mechanism articulated with subnational levels. [Extended with rephrasing]

        § Enhance and maintain operational readiness respond to BVD cases, focusing on gaps identified through BVD-specific readiness assessments, and including, but not limited to:

        § identifying areas at highest risk of importation of BVD cases;

        § raising community awareness regarding BVD;

        § raising awareness among health workers regarding BVD;

        § enhancing community-based surveillance for and investigations of clusters of unexplained deaths;

        § establishing weekly zero reporting of suspected BVD cases across health facilities;

        § establishing timely access to laboratories, at national and, if needed, at subnational levels, qualified to perform test for BDBV and relevant differential testing. Considerations may be given to shipment to an international reference laboratory for inter-laboratory comparison as part of external quality assurance implementation;

        § establishing rapid response teams for the investigation and management of BVD patients and their contacts;

        § establishing a mechanism for the identification and monitoring of contacts;

        § training health workers in infection, prevention and control (IPC) measures and interventions, including standards and transmission-based precautions for the isolation and treatment of BVD cases;

        § identifying and training workforce should a rapid scale-up of response operations be necessary, including the identification of resources for hazard pay; and

        § conducting simulation exercises.

[Modified, including merging of two temporary recommendations previously under this Section]

        § Provide the general public with accurate and up to date information regarding the BVD epidemic, as well as measures to reduce the risk of exposure; and, where the risk of importation is assessed as highest, engage community leaders, community health workers, and trusted community actors to promote protective behaviours, conduct surveillance, facilitate referral of suspected BVD cases, collect and respond to community feedback [Modified]

        § Establish, with a view to support research, expedited and efficient national regulatory and ethics reviews, community engagement, pharmacovigilance (where applicable), data sharing and equitable access arrangements. [Extended]

Border health and international travel

    ° Provide travellers with accurate and up to date information regarding the BVD epidemic and measures to reduce the risk of exposure, including discouraging travel to areas with community BVD transmission. [Modified with rephrasing]

    ° Establish arrangements with States Parties with adjacent areas experiencing community BDV transmission and characterised by substantial cross border movement and trade activities, to enhance surveillance at ground crossings and along bordering areas. This includes establishing coordination mechanisms for the detection and assessment of travellers with unexplained febrile illness; and the timely sharing of information regarding contacts who have, or may have, crossed the border, thus enabling continuity of follow-up. [Extended with rephrasing]

    ° Pre-position PPE, other IPC materials, sample collection kits, case investigation forms, and safe burial supplies in border areas and points of entry, prioritizing those where the risk of importation is assessed as highest. [Extended with rephrasing]

    ° Activate health contingency plans at airport, ports, and ground crossings, involving conveyance operators, to detect, assess, and manage travellers from States Parties with community BDV transmission, presenting with symptoms compatible with BVD, and the identification of their contacts, according to established protocols. This entails the availability of trained personnel, referral mechanisms, and the application of IPC measures. [Extended with rephrasing]

    ° Coordinate with conveyance operators to facilitate timely communication, prior to arrival, of any suspected BVD cases on board conveyances, and to identify contacts associated with conveyances on an international voyage. Conduct international contact tracing operations as necessary, including by obtaining relevant information from the operators; identifying contacts associated with conveyances on an international voyage; and communicating with States Parties known as transit or final destination of those contacts. [Modified, including merging of one temporary recommendation previously under this Section]

    ° Neither the suspension of flights or waterways routes with States Parties with community BDV transmission, nor denial of entry to travellers and conveyances arriving from those States Parties, are recommended. [Extended with rephrasing]

    ° Report to WHO, through the relevant WHO IHR Contact Point, the implementation of any international traffic related measure adopted. [Extended]

    ° Treat as a health emergency, including, when warranted or necessary, through a formal declaration according to domestic laws, the detection of a suspected or confirmed BVD case, of a contact thereof, or of a cluster of unexplained deaths. This includes investigating any of those events within 24 hours and, by instituting case isolation and management; establishing a definitive diagnosis; and undertaking the identification and monitoring of contacts. [Extended with rephrasing]

    ° Notify to WHO immediately, through the relevant WHO IHR Contact Point in the WHO Regional Offices, any suspected, probable or confirmed BVD case, as per WHO case definitions available here. [Extended]

    ° Report to WHO, on a quarterly basis, on the status of, and challenges related to, the implementation of these temporary recommendations, using a standardized tool and channels that will be made available by WHO, also allowing for the monitoring of progress and the identification of gaps in the national response. [Modified]

    ° In the presence of a probable or confirmed BVD case, take actions based on the temporary recommendations for States Parties with community BDV transmission. [Modified]

For all other States Parties

    ° As of 14 August 2026, the WHO Secretariat assessed the risk for these States Parties as “Low”.

    ° Make arrangements to detect, assess, report and manage travellers with unexplained febrile illness arriving from areas with community BDV transmission. These include, but are not limited to, disseminating accurate and up to date information regarding the BVD epidemic and the definition of BVD cases to public and private health care facilities, including travel clinics, general practitioners, and authorities at points of entry; identifying laboratories to conduct testing for BDBV; identifying isolation facilities allowing for safe assessment and clinical care. [Extended with rephrasing, incorporating a temporary recommendation previously under this Section]

    ° Provide non-governmental organizations and other entities deploying personnel internationally to respond to the BVD epidemic with information on risk, measures to minimize the risk of exposure, and advice for managing a potential exposure. [Extended]

    ° Prepare to facilitate the evacuation and repatriation of nationals (e.g., health workers) who have been exposed to BVD cases. [Extended]

    ° Provide the general public with accurate and up to date information regarding the BVD epidemic and measures to reduce the risk of exposure, including discouraging travel to areas with community BDV transmission. [Extended with rephrasing]

    ° Provide, at points of entry, incoming travellers from areas with community BDV transmission, with information about measures to take should they develop symptoms compatible with BVD within 21 days after arrival. [Extended with rephrasing]

    ° Coordinate with conveyance operators to facilitate timely communication, prior to arrival, of any suspected BVD cases on board conveyances, and to identify contacts associated with conveyances on an international voyage. Conduct international contact tracing operations as necessary, including by obtaining relevant information from the operators; identifying contacts associated with conveyances on an international voyage; and communicating with States Parties known as transit or final destination of those contacts. [Modified]

    ° At the time these temporary recommendations are issued, neither the suspension of flights from States Parties with community BDV transmission, nor denial of entry to travellers and conveyances arriving from those States Parties, are recommended. [Extended]

    ° Report to WHO, through the relevant WHO IHR Contact Point, the implementation of any international traffic related measure adopted. [Extended]

    ° Notify to WHO immediately, through the relevant WHO IHR Contact Point in the WHO Regional Offices, any suspected, probable or confirmed BVD case, as per WHO case definitions available here.

    ° In the presence of a probable or confirmed BVD case, take actions based on the temporary recommendations for States Parties with community BDV transmission. [Modified]

Source: 

Link: https://www.who.int/news/item/24-08-2026-second-meeting-of-the-ihr-emergency-committee-on-the-epidemic-of-ebola-bundibugyo-virus-disease-in-the-democratic-republic-of-the-congo-temporary-recommendations

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#Mpox, Multi-Country #Outbreak - Rapid #risk #assessment V7 (#WHO, August 25 '26)

{Summary}

    ° Date and version of current assessment: 18 August 2026, v7

    ° Overal Global Risk statement: 

        § This global rapid risk assessment (RRA) assessesthe current public health  risk associated with the 2024 upsurge of mpox in Africa, in the context of the  continuing global occurrence of mpox in all regions since 2022, with a focus on  updates since the previous RRA in February 2026. 

        § The overall public health risk  posed by mpox remains unchanged from the last RRA. 

Global overview

    As of 30 June 2026, the monkeypox virus (MPXV) continues to spread  globally, causing both localized and extended mpox outbreaks driven by multiple  MPXV clades (Ia, Ib, IIa, and IIb) in diverse settings. The recombination of MPXV clades has also been documented, with the two previously reported cases  of a recombinant clade Ib/IIb MPXV strain detected in the United Kingdom of Great Britain and Northern Ireland in late 2025 and India in January 2026,  and one additional case reported in Qatar since the last RRA.

    Globally, from 1 January 2022 to 30 June 2026, 145 countries and  territories across all WHO regions reported 188 847 confirmed cases of mpox,  with 521 deaths [case fatality ratio (CFR) – 0.3%] and including two  additional countries: Comoros and Guinea-Bissau. 

    Since the last RRA, an additional 10 908 confirmed cases, 44 deaths,  and an average of 420 new confirmed mpox cases per week have been reported  across all affected countries. 

    As with the previous version, this RRA assesses the risk for three population groups; 

        i) global risk for individuals with multiple sexual partners, 

        ii) risk for children in mpox historically endemic areas where risk of zoonotic  transmission continues, and 

        iii) global risk for all other individuals. Updates in understanding of mpox  epidemiology within these groups are described herein.

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. The major and  predominant contribution of sexual transmission, whether linked to  heterosexual or same-sex contact, to the introduction, spread and  establishment of mpox in communities has been recognized across all affected  settings. 

    Outside the WHO African Region, over 87% of reported cases have been among men who have sex with men (MSM), with transmission driven by  spread among individuals with multiple sexual partners in a short time span  and/or frequent partner change. 

    Outbreaks are commonly linked to a sex-on-premises location or event.  In Africa, transmission has often been reported to involve sex workers and their  clients, long-distance drivers and other sexual networks where people have  multiple partners and/or frequent partner change. In Africa, most transmission  appears to be heterosexual.

    In networks characterized by multiple partners and/or frequent partner  change over short periods (days to a few weeks), the secondary attack rate for  sexual contact may be high (estimated at 73% in some settings), facilitating epidemic spread. This pattern was observed during the initial spread of  clade IIb MPXV among MSM communities and more recently clade Ib and IIb  MPXV outbreaks in Africa and elsewhere, with amplification in key populations  such as female sex workers and their clients as well as others with multiple  partners, often in different locations. The recently identified recombinant clade  Ib/IIb strain of MPXV has also been identified in this group with similar risk factors  related to sexual contact. This risk group therefore includes people with multiple or frequently changing sex partners, including those with higher-risk  sexual behaviours.

    Sexual contact transmission likely occurs during various stages of  infection, including pre-symptomatic or less apparent stages, the duration of  which can vary between individuals. People with few or mild genital lesions might not recognise the infection. Studies have shown that the virus can be  present in genital and anal mucosae, as well as in seminal and vaginal fluids  of symptomatic infected individuals. Emerging data suggests that viral  shedding from the genitals may occur up to four days before symptom onset,  potentially contributing to undetected sexual contact transmission. This could  explain the persistence of the virus in communities and the challenges  encountered in interrupting human-tohuman transmission, while the contribution  of asymptomatic viral carriage to transmission remains unclear.

    In most healthy adults of this group, mpox is often self-limiting.  However, severe disease, including disabling complications, secondary infections,  long-term sequelae and death, continues to occur most particularly but not exclusively in people living with advanced HIV disease or uncontrolled HIV  infection, as well as other immunocompromising conditions. While overall case  fatality has remained below 1% in most settings, up to 15-fold or higher fatality has been observed among individuals with immunosuppression, as well as in vulnerable infants, and particularly neonates  in some settings. Notably, recent data from the African setting support  observations elsewhere that people living with HIV who have suppressed viral loads and preserved CD4 counts experience mortality equivalent to HIV-negative individuals, indicating that the HIV-associated  mortality risk is largely modifiable and deaths are preventable through sustained  viral suppression and immune reconstitution. Although most people living with HIV globally are on antiretroviral therapy, significant and growing gaps in  diagnosis and treatment persist in several lowand middle-income settings, with  26.3 million people estimated to be living with HIV in Africa in 2025, of which over 20% either do not know their status, are not on antiretroviral therapy or are  not successfully virally suppressed, a situation exacerbated by recent funding cuts  to HIV control programmes in many countries. In many contexts, over half of mpox cases are reported among people living with HIV, adding  more complexity to the convergence of risks faced by this group (risk of infection,  risk of severe disease, and risk of poorer health service access).

    Most countries globally have activated outbreak responses, including  surveillance, case investigation, contact tracing, case management, and infection  prevention and control. However, control efforts have been impeded when sexual contact transmission or other risk factors are not adequately recognized, or  when risk communication and community engagement do not effectively reach  key populations and other individuals within sexual networks. Furthermore, countries are increasingly tasking HIV/STI control programmes –  themselves heavily constrained by recent funding cuts – with participating in or  leading the response, as well as activating immunization policies and programme  capacity.

    While targeted mpox vaccination has been implemented for groups at  higher risk of mpox exposure in many countries in high and low-income settings,  including administration of more than two million doses in Africa, coverage  remains uneven or partial and most individuals in this group remain susceptible to  MPXV infection, particularly in countries outside Europe and North America. In  addition, younger cohorts are continually entering sexually active age groups.

    The duration and level of protection conferred by prior infection and/or vaccination remains uncertain. 

    Overall, transmission in these groups at higher risk is ongoing and likely  to continue to spread geographically, which can be expected to lead to  severe outcomes among immunocompromised individuals, thus focusing  risk of spread among individuals with multiple partners in interconnected sexual  networks who may not be aware of risk, and the risk of complications and death  among vulnerable individuals. 

    The overall public health risk for individuals with  multiple sexual partners is, therefore, assessed as moderate.

Children in historically endemic areas – local risk

    In historically endemic areas in West and Central African countries,  where viruses continue to circulate in animal hosts and zoonotic spillover  continues to occur, particularly in the Democratic Republic of the Congo, the  highest number of mpox cases and incidence of deaths has been documented  among young children (<5 years). Surveillance and diagnostic capacities in these  settings remain suboptimal and have continued to decline in 2026, making the interpretation of available data challenging.

    Among individuals younger than 50 years in the Democratic Republic of the Congo, age-specific mpox incidence appears broadly comparable across age  groups, largely reflecting the underlying age distribution of the population.  However, case fatality among suspected mpox cases in children under five years of age (CFR 3.0%) is higher  than that observed among individuals aged  five to 15 years (CFR 1.9%), and almost twice that observed among  individuals aged 15 years and older (1.7%). Of note, the case fatality ratio in  historically endemic areas of the Democratic Republic of the Congo remains much  higher across all age groups than elsewhere (about 7 to 20-fold higher). This may  arise from specific vulnerabilitiesincluding delayed or limited access to appropriate  health care, compounded by concomitant health risks, such as  malaria, varicella, measles, malnutrition, and complications of mpox such as  dehydration and secondary infections. This higher fatality is particularly observed  in infants and young children, who are largely immunologically naïve. At present,  mortality data from this setting are largely drawn from syndromic surveillance  and multiple studies are underway to better describe the risks  associated with mpox in these settings.

    While targeted vaccination has supported outbreak response, in the  absence of established vaccination programmes against mpox and limited access  to early and appropriate healthcare, children and pregnant women in the affected  settings are likely to continue experiencing elevated health risks from  mpox and MPXV infection.

    The risk of geographic spread associated with non-sexual contact transmission is predominantly local. Available data indicate secondary attack  rates of less than 20% following non-sexual household contact, suggesting that  while children are vulnerable to more severe disease, and outbreaks in schools  have been documented , children generally appear to have a limited role in  driving viral spread. In addition, children have not often been reported as a source  of introduction of mpox in new areas, and their contribution to wider  geographic or cross-border spread remains negligible, compared to spread among adults exposed through sexual contact.

    Most historically endemic areas are rural forested territories, where  there is a risk of insufficient control capacities of outbreak response, particularly  now as countries transition from an acute outbreak response approach to a  longerterm disease control programme. Mpox programmes in these settings have  previously been greatly under-resourced and will increasingly need to rely on  preventive strategies and routine care capacity.

    Overall, in the absence of vaccination programmes for mpox in  historically endemic areas, and resources for national programmes conducting  outbreak response activities, the virus will likely continue to circulate,  disproportionately affecting younger children. 

    The overall public health risk for children in historically endemic areas is,  therefore, assessed as moderate.

All other individuals – global risk

    For individuals outside the above two risk groups, the overall risk of acquiring mpox is lower. While illness in the general population is typically mild  and self-limiting, with most cases requiring only supportive care and no  hospitalization, severe disease and death can also occur, albeit less commonly.  While the risk of severe outcomes is much higher among individuals with  underlying immunocompromising conditions, these persons generally represent a  small proportion of cases reported in recent outbreaks, and thus the majority of  cases with complications or deaths may actually occur in persons without immune  suppression in some settings. As noted above, case fatality in historically endemic  areas of the Democratic Republic of the Congo remains much higher across all age  groups than elsewhere (about 7 to 20-fold higher). More research is needed  to characterise less studied risk factors for severe disease. 

    Some data suggest that adults vaccinated before the cessation of routine smallpox vaccination worldwide , in 1980 or earlier in many  countries, are likely to retain partial cross-protective immunity and present with  lower disease severity.

    While breakthrough cases of mpox have been documented in some older  previously vaccinated persons, epidemiological data indicate that few mpox  deaths have been reported in this group. New cases of mpox with clade Ib  MPXV in various regions have predominantly been associated with sexual contact  in people with a history of travel to outbreak-affected areas who developed  symptoms just prior to or upon return. Spread through sexual networks from  some cases has ultimately led to the establishment of community transmission of  clade Ib MPXV in several countries outside Africa.

    Overall, the spread of clade Ib MPXV in newly affected areas has remained largely confined to groups at risk. Since the start of the global  outbreak in 2022, the general population has not been widely affected by ongoing  circulation of clade IIb MPXV in high income settings, nor has it been implicated in  mpox introduction or establishment in new geographic areas. Secondary  transmission to non-sexual contacts has remained limited. Thus, individuals in this  risk group (“all other individuals”) affected by clade IIb have mainly been  infected through household or occupational contact, characterized by low  secondary attack rates and limited onward transmission. Nonetheless, explosive  outbreaks in West Africa have demonstrated that all age groups can be  significantly affected such that continued vigilance is required for all mpox clade  outbreaks in different settings. Within this broad group which includes most  people, there are also other individuals in settings where there is a higher risk of  onward mpox transmission, such as those in internally displaced person (IDP) and  refugee camps and other congregate, overcrowded settings. Furthermore,  some more vulnerable individuals are considered to face a higher risk of severe  disease and poorer disease outcomes if they fall ill, particularly pregnant  individuals, neonates, and infants. Poor outcomes have been documented among  pregnant individuals and their unborn children, including spontaneous  abortions, missed abortions, still births, congenital mpox and early neonatal  death, with recent studies reporting these adverse outcomes in about half of  pregnant individuals followed up. The healthcare-associated clade Ib mpox outbreak among neonates and infants in Pakistan in early 2026 which  resulted in a CFR higher than 20% also demonstrated that mpox transmission can  lead to severe consequences in highly vulnerable populations. In this instance,  mpox in a neonatal intensive care setting resulted in rapid amplification and disproportionate impact in neonates and infants.

    Public health control measures such as laboratory confirmation, rapid  contact tracing and isolation have generally been sufficient to manage mpox in the  general population, notably in high-income settings. Nonetheless, partner  notification strategies should supplement classic contact-tracing to reach non- disclosed sexual partners. Vaccination has been prioritized for groups at higher  risk of exposure with the intent to prevent and stop transmission. Where vaccines  have, in some settings, been mainly offered to health workers for their individual  protection, this strategy builds confidence and quality of care but cannot be  expected to play a major role in stopping outbreaks.

    In all settings therefore, the general population largely remains  immunologically naïve to mpox, while the risk to health, contribution to  international spread and burden of insufficient response capacities, remains low.  Exceptions to this include where mpox is inadvertently introduced into high-risk  settings, such as newborn and infant care units. 

    The overall public health risk for all other individuals without multiple sexual partners is, therefore, assessed as low.

Overall public health risk

    Mpox continues to pose a public health risk across all WHO regions,  with the likelihood and impact varying by population group, transmission context,  and local response capacity. The African Region will most likely continue observing  sustained community transmission in several countries  outside historically endemic areas, as well as recurrent outbreaks in countries  where zoonotic transmission occurs. While all countries remain at risk of  importation and limited local transmission, recent outbreaks (starting from 2022- 2023) have confirmed observations that sustained transmission and geographic  spread are largely driven by sexual contact in specific population groups and  network dynamics, rather than in the general population, with some notable  exceptions such as health facility-based outbreaks.

    While most countries have established outbreak response mechanisms,  such as early detection and contact tracing that help in controlling  viral spread, the effectiveness of classic contact-tracing for a sexually  transmissible infection remains very limited. Other countries are less prepared and  at a higher risk of missing chains of local transmission, especially where low  index of suspicion, stigma, and discrimination create barriers to access diagnostic testing, clinical care services and implementation of infection prevention and  control measures, and where political and socio-cultural  contexts or other  circumstances preclude timely information-sharing with communities, health  sector partners and timely and complete reporting to WHO.

    While improvements in understanding mpox transmission and risk have  improved since the first mpox public health emergency of international  concern (PHEIC) was declared in 2022, important knowledge gaps remain. These  include uncertainties regarding the role of asymptomatic or pauci-symptomatic  infections, the duration and extent of immunity  following infection or vaccination  (e.g., for immunocompromised individuals), risk factors for severe disease beyond known immunocompromising conditions, and the contribution of zoonotic  spillover and potential human-to-animal transmission. Limited data regarding  animal reservoirs and transmission at the human–animal–environmental interface further limits risk characterization in endemic settings. The lack of  reporting by some countries further limits overall community awareness,  appreciation of risk, and visibility on continuing evolution of the epidemic.

    Several cases and larger outbreaks have been reported in humanitarian emergency settings such as IDP and refugee camps and other congregate,  overcrowded settings, but the risk of spread and modes of transmission in these  settings, including the role of living conditions among other factors, are still poorly  understood. Additionally, transmission between children outside of the  household setting is not fully understood, and its potential to sustain spread of the  virus in the community context has not been quantified.

    In recent years, access to diagnostics, vaccines, and response tools has  improved through coordinated efforts by WHO and partners, and 19 countries  in Africa have implemented vaccination for populations at highest risk.  However, funding constraints, competing public health priorities, and reliance on  limited resources for vaccine supply continue to challenge sustained response  efforts, particularly in low- and middle-income countries. Delays in vaccine  introduction and limited coverage reduce the potential impact of vaccination,  underscoring the importance of prioritization and timely vaccine deployment. In  addition, data on the effectiveness of available therapeutics for mpox remain  limited, particularly in settings reporting the highest burden of disease.

    The detection of a recombinant MPXV strain with genetic elements of  both clade Ib and IIb MPXV warrants continued monitoring. To date, one  additional case has been detected since the last RRA, bringing the cumulative case  count to three. The geographic areas where the recombination event first  occurred remain unknown. While the public health risk associated with this  recombinant strain is currently considered low, ongoing genomic surveillance is  essential given uncertainties related to viral evolution and recombination.

    Overall, MPXV continues to circulate in all WHO regions and pose distinct risks across different population groups and  settings. Sustained  transmission of this still emerging and evolving orthopoxvirus continues, posing  health risks for vulnerable individuals of all ages and in all settings. While  response capacity continued to improve during the second PHEIC, it remains  uneven with suboptimal reporting practices, and highly dependent on dwindling or  non-existent resources as priorities shift. Transition to longer term disease  prevention and control programmes and strategies is still in early stages in most  settings and resources remain extremely limited as interest in mpox response  wanes. Taken together, this context creates additional risk that the gains made  over the past few years may erode. 

    Thus, the overall public health risk at the global level is assessed as moderate.

(...)

Source: 

Link: https://www.who.int/publications/m/item/who-rapid-risk-assessment-mpox--global-v.7

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#Taiwan, #Epidemics of Respiratory Viruses (#COVID19, #Influenza, #Enteroviruses) Weekly Update (CDC, August 25 '26): PQ.16.1.1 Variant Still Predominant

 

{Excerpts}

(...)

    CDC monitoring data shows that the domestic COVID-19 epidemic is at a plateau. 

    In week 33 (August 16-22), there were 24,995 outpatient and emergency room visits for COVID-19, a 6.0% decrease compared to the previous week (August 9-15). 

    Last week (August 18-24), there were 59 new locally transmitted severe cases and 19 new locally transmitted deaths. 

    Since October 2025, there have been a total of 480 local cases of COVID-19 complicated by severe illness, of which 73 have died. 

    The majority of severe cases are among those aged 65 and above (73.5%) and those with a history of chronic diseases (82.5%). 86.5% of these cases have not been vaccinated this season. 

    In the past four weeks, the predominant variant strain in local cases has been PQ.16.1.1.     

    As of August 24, approximately 1.823 million doses of the COVID-19 vaccine have been administered this season. There are currently about 111,000 doses remaining nationwide, which will be available until September 9. Eligible and needy individuals are advised to take advantage of this time and get vaccinated as soon as possible.

    Regarding the influenza epidemic, in week 33 (August 16-22), there were 94,340 outpatient and emergency room visits for influenza-like illnesses, a slight decrease of 2.5% compared to the previous week. 

    Additionally, last week (August 18-24), there were 64 new cases of severe influenza complications (59 H1N1 and 5 H3N2) and 15 deaths (all H1N1). 

    Laboratory surveillance data shows that the influenza virus currently circulating in the community is predominantly type A, with type A H1N1 accounting for a high percentage at 69.7%. 

    This flu season (2014-2015) saw a cumulative total of 1,139 severe cases (540 H1N1, 491 H3N2, 18 untyped A, and 90 B) and 220 deaths (101 H1N1, 101 H3N2, 6 untyped A, and 12 B). 

    The majority of severe cases were among those aged 65 and over (63.8%) and those with a history of chronic illness (82.4%). 71.0% of patients had not received the flu vaccine this season.

    Regarding enterovirus cases, in week 33 (August 16-22), there were 6,546 outpatient and emergency room visits, similar to the previous week (6,646), indicating a stable recent trend. 

    Laboratory surveillance over the past four weeks showed that Coxsackievirus A6 was the most prevalent enterovirus in the community, followed by enterovirus D68 and Coxsackievirus A16. 

    This year (2026), there have been a total of 6 confirmed cases of enterovirus infection complicated with severe illness (including 1 death), including 4 cases of enterovirus D68, 1 case each of Coxsackievirus A4 and Coxsackievirus A16. 

    Regarding the dengue fever outbreak, as of August 24th this year, there have been a total of 134 confirmed dengue fever cases, including 7 local cases (all residing in Kaohsiung City) and 127 imported cases. The imported cases were mainly from Southeast Asian and South Asian countries such as Indonesia (26 cases), Vietnam (26 cases), and the Maldives (16 cases). The cumulative number of cases is lower than the same period in 2025 (152 cases).

(...)

Source: 

Link: https://www.cdc.gov.tw/Bulletin/Detail/QiAsLBvifNAj7FJzGc-ApQ?typeid=9

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COMbination #therapy with #baloxavir and #oseltamivir 1 for hospitalized patients with #influenza: The pragmatic COMBO 1 randomized controlled trial

 

Abstract

Background

COMBO 1 compared time to cessation of viral shedding (TCVS) among hospitalized influenza patients treated with oseltamivir plus a single dose of baloxavir vs. oseltamivir alone.

Methods

In a quadruple-blinded, placebo-controlled parallel group multicenter randomized controlled trial, hospitalized patients with laboratory-confirmed influenza were randomly enrolled in a 1:1 ratio to Group 1 (oseltamivir+placebo) or Group 2 (oseltamivir+baloxavir). All patients were treated with oseltamivir for 5 days; one dose of baloxavir or placebo was given in identical capsules. Primary efficacy and safety outcomes were TCVS by virus titer with qCulture TCID50 agglutination and 30-day severe adverse event (SAE) rate, respectively. Secondary virology, clinical, and safety outcomes were assessed. Continuous and categorical data were analyzed with Wilcoxon Rank-Sum and Fisher’s Exact Tests, respectively.

Results

14 participants were randomized and received study drug (Group 1: n=6, Group 2: n=8); the study was stopped early due to slow accrual. Baseline characteristics were balanced. Median TCVS with qCulture was 53.3 hours in Group 1 and 25.3 hours in Group 2 (p=0.13). 30-day overall SAE rates were 16.7% and 12.5%, respectively. All patients achieved negative qCulture. Median TCVS with quantitative PCR (RT-qPCR) was 115.6 and 34.4 hours (p=0.24); % achieving viral negative by RT-qPCR was 33.3% and 75.0% (p=0.28), respectively.

Conclusions

Combination therapy with oseltamivir and a single dose of baloxavir was inconclusive with non-significant trends towards shorter median TCVS vs. monotherapy with oseltamivir in hospitalized patients with influenza. Interpretation is limited by small sample size and early termination.

Source: 

Link: https://journals.sagepub.com/doi/10.1177/13596535261479944

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#Italy: A Suspected Imported #Ebola {Bundibugyo} case tested negative (Autonomous Province of Trento, August 24 '26)

 

Laboratory tests performed by the Luigi Sacco Hospital in Milan on the suspected Ebola case reported in Trentino yesterday were negative. The tests therefore ruled out infection.

    The Ministry of Health's protocol for suspected Ebola cases was activated yesterday after an adult returning from a trip to the Democratic Republic of Congo exhibited symptoms consistent with the virus. 

    

    The individual was immediately placed in isolation at home, and healthcare workers collected biological samples and delivered them to the Luigi Sacco Hospital in Milan. 

Source: 

Link: https://www.ufficiostampa.provincia.tn.it/Comunicati/Caso-sospetto-di-Ebola-esito-negativo-dai-test-di-laboratorio

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Characterisation of a #human monoclonal #antibody targeting a conserved epitope at the base of the HA head of #influenza #H3N2 virus

 

Summary

Background

Numerous broadly reactive human monoclonal antibodies (mAbs) against the haemagglutinin (HA) of influenza A viruses have recognised conserved epitopes across HA subtypes or within subtypes. Most heterosubtypic mAbs target the HA stem, the receptor-binding site (RBS), or the trimeric interface. Although at least three H3-specific mAbs recognise epitopes outside these regions, the overall landscape of conserved H3-specific epitopes remains incompletely understood. This study aimed to identify and characterise conserved epitopes on H3-HA to inform the development of vaccines resilient to antigenic change.

Methods

We screened a panel of previously reported H3-HA-reactive human mAbs to identify mAbs recognising conserved epitopes. The candidate clone, 034-10040 4F02 (4F02), was evaluated for neutralising, haemagglutination inhibiting, and HA-mediated fusion-inhibitory, Fc receptor-mediated effector functions in vitro, and for protective efficacy in a lethal mouse challenge model. Cryo-electron microscopy was used to define the structural basis of 4F02 binding. Human sera were screened for antibodies targeting similar epitopes.

Findings

Clone 4F02 recognised the HA of human influenza A (H3N2) viruses that circulated across multiple decades. It neutralised multiple H3N2 viruses, exhibited weak haemagglutination inhibition, blocked HA-mediated fusion activity, activated Fc receptor-mediated signalling, and protected mice against lethal challenge. Cryo-electron microscopy revealed that 4F02 targets the base of the HA head at a head-stem interface spanning antigenic sites C, D, and E. Antibodies targeting similar epitopes were detected, albeit at a low level, in human sera.

Interpretation

Characterisation of the 4F02 epitope reveals a previously underappreciated site of vulnerability at the H3-HA head-stem interface. This finding expands our understanding of conserved epitopes and provides a target for the development of influenza vaccines resilient to antigenic change.

Funding

This work was supported by the Japan Agency for Medical Research and Development, JSPS KAKENHI, the National Institutes of Allergy and Infectious Diseases.

Source: 

Link: https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(26)00334-8/fulltext

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