Increased contact #transmission of contemporary #Human #H5N1 compared to #Bovine and Mountain #Lion H5N1 in a hamster #model

 

Abstract

The ongoing outbreak of highly pathogenic avian influenza virus (HPAIV) subtype H5N1 in the U.S. poses a significant public health threat. To date, 70 human cases have been confirmed in the United States, including two severe cases and one fatality. While suitable animal models are crucial for predicting the potential pandemic risk of newly emerging pathogens in humans, studies investigating contemporary HPAIV H5N1 transmission dynamics remain limited. Here, we investigate the pathogenicity and transmission efficiency of recent clade 2.3.4.4b H5N1 viruses isolated from a bovine, mountain lion, and a human case using Syrian hamsters. Intranasal inoculation results in productive virus replication in the respiratory tract and shedding for all three isolates. Transmission studies demonstrate limited efficiency via direct contact and airborne routes for all isolates. Although overall transmission is inefficient, the human H5N1 isolate demonstrates relatively greater contact transmissibility than the bovine and mountain lion isolates. Taken together, our findings demonstrate that the Syrian hamster model complements existing animal models for influenza A virus research and expands the resources available for investigating the pathogenicity, transmissibility, and efficacy of countermeasures against HPAIV H5N1.

Source: 

Link: https://www.nature.com/articles/s41467-026-68900-8

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#International #food safety event: #Infant #formula and products containing arachidonic acid oil contaminated with #cereulide #toxin - Multi-country (#WHO, March 13 '26)

 

Situation at a glance

Multi-country recalls of infant formula and other products have been initiated after cereulide toxin, was detected in batches of multiple internationally distributed brands. 

Investigations have identified arachidonic acid (ARA) oil, used as an ingredient in the implicated products, as the source of contamination. 

However, the full root cause analysis and complete traceability of all affected batches remains under investigation. 

Contaminated formulae, nutritional products, and oil mixes have been distributed to 99 countries and territories across six WHO Regions, with the first product recalls initiated on 10 December 2025. 

Between 1 January and 25 February 2026, 144 suspected and confirmed cases were reported across ten countries in three WHO Regions, with investigations ongoing. 

Based on the available information, WHO assesses the overall public health risk as moderate due to the vulnerability of the affected population (infants), the ongoing uncertainty regarding the full extent of distribution and exposure, and remaining gaps in case detection and root cause information.

Description of the situation

Since 10 December 2025, and as of 25 February 2026, 99 countries and territories have been identified as having received batches of infant formula products subject to recall due to contamination with cereulide toxin. 

During this period, 144 suspected and confirmed cases were reported across 10 countries. The epidemiological investigations and product‑traceback activities remain ongoing in many countries.

The case definitions in use by the International Food Safety Authorities Network (INFOSAN) are currently:

-- Suspect case: 

- A person presenting symptoms of cereulide intoxication with a history of consumption of the recalled product, without laboratory confirmation in a clinical sample.

-- Confirmed case: 

- A person presenting symptoms of cereulide intoxication with a history of consumption of recalled product, with laboratory confirmation in a clinical sample.

Health authorities are actively searching for cases and conducting laboratory testing of human specimens and infant formula products. 

However, case definitions used may differ from those established by INFOSAN, such as those established by the European Centre for Disease Prevention and Control, creating challenges with comparability of reported case numbers.

Since this is not a routinely tested contaminant or condition, diagnostic challenges and limited surveillance capacity are hindering Member States’ ability to identify confirmed cases. One country has laboratory confirmed cases linked to the contaminated products (Belgium).

The limited case numbers appearing in multiple, geographically separated areas is consistent with sporadic exposures to contaminated products that were widely distributed.

​Precautionary recalls have been issued across all countries and territories where products were distributed. 

These measures aim to prevent further exposures, although the speed and completeness of product recall and withdrawal vary by location according to various factors including inspection and enforcement capacities. 

Epidemiology

Cereulide is a heat-stable toxin produced by certain strains of Bacillus cereus, a Gram-positive, spore-forming bacterium ubiquitous in soil, dust, and food production environments. 

The primary hazard in this event is suspected to have occurred during the production of ARA oils used in infant formula, although a root cause analysis has not yet been provided to WHO. 

Cereulide is not contagious; illness occurs only when a person ingests the toxin, such as through consumption of contaminated products. 

The toxin withstands cooking temperatures (stable up to 121°C) and common pasteurization, persisting in finished products. 

Symptoms manifest rapidly, typically within 0.5–6 hours post-ingestion, and usually present as acute gastrointestinal symptoms (nausea, vomiting, abdominal pain) with risk of rapid dehydration and electrolyte imbalance which can be particularly severe in infants due to their physiological vulnerability and limited reserves. 

The toxin has a very low symptomatic dose threshold and remains fully active despite gastric conditions, contributing to its clinical potency. 

For babies who rely entirely on formula, repeated feedings can increase the amount of toxin consumed, and using contaminated formula for rehydration can worsen illness.

The absence of specific antidotes or targeted therapies places greater emphasis on supportive clinical care, effective risk communication to caregivers and health workers, and robust coordination between food safety and public health authorities. 

Where there is limited access to health care and where there may be delays in care seeking, rapid dehydration and electrolyte imbalance in infants may be fatal.

As of 25 February 2026, the following countries have notified suspected cases: 

1) Austria (9), 

2) Brazil (5),  

3) China, Hong Kong SAR, (1), 

4) Czechia (4), 

5) France (11), 

6) Italy (1), 

7) Singapore (3), 

8) Spain (41), and 

9) the United Kingdom of Great Britain and Northern Ireland (61).  

In other countries, including Denmark (32) and the Netherlands (221) the number of suspected cases is based on self-reporting and is therefore not comparable with the INFOSAN case definition.  

To date, Belgium is the only country with laboratory‑confirmed cases, reporting eight confirmed intoxications linked to the implicated products.

Public health response

WHO Response: 

Since 7 January 2026, when distribution of the products was confirmed to extend beyond the European Union, WHO, through the INFOSAN Secretariat, has been contacting INFOSAN Emergency Contact Points in the countries and territories identified as affected to notify them of recalled products exported to their markets and to support information exchange and coordinated response. 

Communication within the European Union has been managed through the European Rapid Alert System for Food and Feed (RASFF), with close coordination between INFOSAN and RASFF.

Response measures in affected countries and territories:

Recalls and communication campaigns have been carried out in many countries and territories where contaminated products were distributed, preventing further exposures despite variable implementation of recall and withdrawal measures. 

Active case-finding and laboratory confirmation efforts are ongoing in affected countries and territories, with most countries and territories reporting no linked illnesses to date.

WHO risk assessment

WHO assesses the overall public health risk associated with this event to be Moderate. 

This assessment is based on the information currently available and reflects the wide international distribution of contaminated products, ongoing uncertainties regarding the full extent of contaminated product distribution, case detection, and root cause of contamination, and the vulnerability of infants and young children to dehydration and electrolyte imbalance from with vomiting illness associated with cereulide toxin ingestion.

Several considerations contribute to this assessment:

-- Cereulide is a thermostable emetic toxin that can cause acute vomiting and rapid dehydration particularly in very young infants which can have severe consequences if untreated; mild or self-limiting cases are likely to go unreported, especially in settings with limited healthcare access or diagnostic capacities.

-- The extent of the contaminated ARA oil distribution remains uncertain, as complete traceability from the original implicated manufacturer has not been provided to WHO. 

-- Secondary distribution through commercial supply chains has further complicated efforts to identify all affected products. Additional investigation is required to determine the source and extent of the cereulide contamination. 

-- The international spread of contaminated products has already disrupted trade and supply chains across at least 99 countries and territories, with the possibility of further recalls if additional affected batches or product categories are identified. These recalls, while essential for public health protection, have created a risk of localized shortage of infant formula, particularly in settings where reliance on specific products is high, despite manufacturers’ efforts to increase production of unaffected products. A residual risk of exposure persists while investigations and traceability efforts continue, as competent authorities manage evolving distribution information and update risk communication measures. 

-- Mild clinical presentations can resemble common childhood illnesses, laboratory capacity for cereulide testing in contaminated products or human samples varies widely, and variations in case definitions across countries complicate consistent reporting and may delay detection. 

-- Although limited numbers of suspected and confirmed cases have been reported to date, without continued investment in surveillance for toxin‑related events, strengthened laboratory networks, training of health‑care providers, and clear communication on recalls and safe alternatives, delays in detection and response could lead to preventable morbidity in infants.

WHO advice

Based on the information available, WHO recommends Member States to maintain epidemiological surveillance, enhance readiness of laboratory capacity for cereulide testing of suspected contaminated products and in clinical samples of suspected cases, and facilitate effective implementation of recalls and withdrawals, as needed.

WHO advises Member States to:  

-- Identify, trace, and withdraw all affected products from the market.

-- Verify the effectiveness of recalls at retail and distribution levels and ensure that affected products are not available for sale, including online sales.

-- Conduct sampling and laboratory testing of suspect products and human specimens.

-- Strengthen requirements for traceability across the supply chain and food recalls.

-- Enhance inspection and oversight of facilities producing or handling ingredients used in infant nutrition.

-- Share relevant information through established international information-sharing mechanisms, including INFOSAN.

-- Issue targeted alerts to consumers, caregivers, health workers, and retailers, while providing clear guidance on identifying and disposing of affected products.

-- Promote breastfeeding and address barriers to accessing safe alternative nutrition.

-- Encourage early presentation to health facilities for infants with sudden vomiting.

-- Reinforce guidance on dehydration management and red-flag symptoms, while supporting availability of tools for safe clinical management of affected infants.

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

-- European Centre for Disease Prevention and Control (ECDC) and European Food Safety Authority (EFSA). Multi-country foodborne event caused by cereulide in infant formula products. 19 February 2026. Available from: https://www.ecdc.europa.eu/en/publications-data/multi-country-foodborne-event-caused-cereulide-infant-formula-products  

-- European Food Safety Authority (EFSA). EFSA provides rapid risk assessment on cereulide in infant formula. EFSA; 1 February 2026. https://www.efsa.europa.eu/en/news/efsa-provides-rapid-risk-assessment-cereulide-infant-formula

-- European Centre for Disease Prevention and Control (ECDC). Communicable disease threats report, 31 January–6 February 2026 (Week 6). ECDC; 12 February 2026. https://www.ecdc.europa.eu/sites/default/files/documents/Communicable-disease-threats-report-week-6-2026.pdf  

-- European Food Safety Authority (EFSA). Precautionary global recall of infant nutrition products following detection of Bacillus cereus. EFSA; 27 January 2026. https://www.efsa.europa.eu/en/news/precautionary-global-recall-infant-nutrition-products-following-detection-bacillus-cereus  

-- European Centre for Disease Prevention and Control (ECDC). Precautionary global recall of infant nutrition products following detection of Bacillus cereus. ECDC; 27 January 2026.  https://www.ecdc.europa.eu/en/news-events/precautionary-global-recall-infant-nutrition-products-following-detection-bacillus  

-- European Centre for Disease Prevention and Control. European outbreak case definition: cereulide contamination of infant formula products (EpiPulse event 2025-FWD-00107). Stockholm: ECDC; 2026. https://www.ecdc.europa.eu/sites/default/files/documents/Case%20definition%20cereulide%20event.pdf

-- World Health Organization. Strengthening surveillance of and response to foodborne diseases. WHO; 11 December 2025. https://www.who.int/publications/i/item/9789240118188  

-- Austrian Agency for Health and Food Safety (AGES). Update: Information on cereulide in infant formula. AGES; 1 February 2026. https://www.ages.at/en/news/detail/update-information-zu-cereulid-in-saeuglingsnahrung  

---

Citable reference: World Health Organization (13 March 2026). Disease Outbreak News;  Recall of internationally distributed infant formula and products containing ARA oil due to contamination with cereulide toxin. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON596 

Source: 

Link: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON596

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#USA, #Wastewater Data for Avian #Influenza #H5 (#CDC, March 13 '26)

{Excerpt}

Time Period: March 01, 2026 - March 07, 2026

-- H5 Detection: 8 site(s) (1.6%)

-- No Detection: 491 site(s) (98.4%)

-- No samples in last week: 77 site(s)

(...)

Source: US Centers for Disease Control and Prevention, 

Link: https://www.cdc.gov/nwss/rv/wwd-h5.html

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#Peru - #Influenza A #H5 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

 

In the framework of passive surveillance activities, a report was received regarding backyard poultry (not considered as poultry) with clinical symptoms consistent with avian influenza. An outbreak of high pathogenicity avian influenza has been confirmed in the Cajabamba district of the Cajamarca department. The birds showed clinical signs such as weakening, hoarseness, eye discharge, and diarrhoea. The Official Authority activated quarantine, control, and surveillance measures in the outbreak and around the outbreak with the aim of identifying possible cases and preventing the spread of the outbreak.

A notification was received regarding sick birds in a backyard (turkeys, ducks, roosters, hens, geese, and chickens) showing signs of depression, diarrhoea, and hoarseness.

Source: WOAH, https://wahis.woah.org/#/home

Link: https://wahis.woah.org/#/in-review/7358

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#UK - High pathogenicity avian #influenza #H5N1 viruses (Inf. with) (#poultry) - Immediate notification

 

{Northern Ireland}

Pheasant breeder flock, with a small mixed backyard flock with chicken, geese. Positive test for HPAI H5N1, clinical signs presented prior to testing.

Source: 

Link: https://wahis.woah.org/#/in-review/7368

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Systematic Identification of the Functional lncRNAs During #H7N9 Avian #Influenza Virus #Infection in Mice

 

Abstract

Accumulating studies have identified the pivotal role of long non-coding RNAs (lncRNAs) in participating in host–virus interactions during virus infections. However, the regulatory roles of lncRNAs in influenza A virus (IAV) infection are still not fully elucidated. In this study, using high-throughput sequencing, we comprehensively compared the expression profiles of lncRNAs and mRNAs in mouse lungs infected either with the nonpathogenic parental (SDL124) H7N9 virus or its moderately pathogenic mouse-adapted (S8) variant. A total of 7636 significantly differentially expressed (SDE) lncRNAs were obtained in the S8-infected group compared to the mock group. As for the SDL124 group, 1042 SDE lncRNAs were identified. Subsequently, the mRNAs co-expressed with SDE lncRNAs were subjected to functional annotation and pathway enrichment analysis. The results indicated that the target mRNAs regulated by the S8 virus were mainly enriched in various immunological processes and exhibited a strong correlation with inflammatory-related signaling pathways. Moreover, 12 lncRNAs and 10 mRNAs co-expressed with SDE lncRNAs were selected and successfully verified by RT-qPCR. Among these lncRNAs, NONMMUG032982.2 and NONMMUG032328.2 exhibited strong antiviral activity against IAV. Additionally, these two lncRNAs were chosen for further in-depth bioinformatics analysis, including transcription factor prediction, coding capacity assessment, genomic location, construction of secondary structure, and prediction of potential interacting proteins. Taken together, these findings provide a cluster of lncRNAs probably associated with the virulence of IAV in mice and shed light on the anti-IAV effects of two functional lncRNAs, establishing a molecular foundation for further exploring the regulatory mechanisms of lncRNAs in IAV infection.

Source: Viruses, https://www.mdpi.com/journal/viruses

Link: https://www.mdpi.com/1999-4915/18/3/353

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#Glycoprotein-specific transcriptional response contributes to differential #vaccine #protection against lethal #Ebola virus #infection

 

Abstract

Since the West African Ebola virus (EBOV) epidemic in 2014-2016, recurrent outbreaks of the EBOV-Makona variant have been driven by recrudescence and human-to-human transmission emphasizing the need for effective vaccination strategies. A live-attenuated recombinant vesicular stomatitis virus (VSV)-based vaccine expressing the EBOV-Kikwit variant glycoprotein (VSV-Kik) received FDA approval in December 2019 and provides complete, rapid protection against EBOV-Makona as early as 7 days post-vaccination (DPV). During the 2018-2020 Ebola outbreak, the VSV-Kik vaccine, known as ERVEBO, was administered to lower-risk individuals at a 5-fold dose reduction of the standard 2 × 107 PFU to provide broader population protection. Identification of a protective lower dose providing rapid protection would ease supply burdens during future outbreaks and enhance vaccine coverage. We previously generated a VSV-based vaccine expressing the glycoprotein of the Makona variant (VSV-Mak) which provided complete protection against homologous challenge 28 DPV at as low as 1 × 101 PFU. However, the transcriptional responses engendered by VSV-Mak and VSV-Kik vaccines in the context of early EBOV-Makona challenge have not yet been evaluated. In the current study, we compared transcriptional responses following a low dose (1 × 104 PFU) of lab-grade VSV-Mak or GMP-grade VSV-Kik and subsequent EBOV-Makona challenge 10 DPV. VSV-Kik provided complete protection against heterologous challenge and elicited rapid antiviral transcriptional changes followed by the activation of adaptive immunity. On the other hand, VSV-Mak only provided partial protection and induced minimal transcriptional response. These results highlight a glycoprotein-specific transcriptional response after vaccination despite the high EBOV variant homology.

Source: Vaccine, https://www.sciencedirect.com/journal/vaccine/vol/79/suppl/C

Link: https://www.sciencedirect.com/science/article/abs/pii/S0264410X26002185?via%3Dihub

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Structural #insights into #antibody responses against #influenza A virus in its natural reservoir

 

Abstract

While influenza A virus undergoes rapid antigenic drift in humans, at least some subtypes, such as H3, have relatively stable antigenicity in natural waterfowl reservoirs, despite the presence of immune pressure. However, the underlying mechanisms remain poorly understood. This study identified and characterized 187 antibodies to H3 hemagglutinin from experimentally infected mallard ducks, 18 of which were further analyzed by cryo-EM. Compared with human H3 antibodies, duck H3 antibodies exhibited higher glycan-binding propensity, more balanced immunodominance hierarchy, and targeted distinct epitopes. Other unique features of duck H3 antibodies included a convergent CDR H3-independent heavy chain-only binding mode and an N-glycosylated CDR H3 as decoy receptor. By annotating duck immunoglobulin germline genes, we also demonstrated the importance of gene conversion in duck H3 antibodies. Overall, our findings provide insights into how millennia of coevolution have shaped the interplay between influenza A virus antigenic drift and antibody responses in the natural reservoir.

Competing Interest Statement

N.C.W. consults for HeliXon. The authors declare no other competing interests.

Funder Information Declared

National Institutes of Health, https://ror.org/01cwqze88, R01 AI165692

Carl R. Woese Institute for Genomic Biology, Carl R. Woese Institute for Genomic Biology Postdoctoral Fellowship

Vallee Foundation, https://ror.org/05nmp3276, Vallee Scholars Program

Foundation for Partnership Initiatives in the Niger Delta, https://ror.org/041nz5a71, Searle Scholars Program

Howard Hughes Medical Institute, https://ror.org/006w34k90, Emerging Pathogens Initiative

Source: BioRxIV, https://www.biorxiv.org/

Link: https://www.biorxiv.org/content/10.64898/2026.03.11.711171v1

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Interim Estimates of 2025–26 Seasonal #Influenza #Vaccine #Effectiveness — #USA, September 2025–February 2026 (CDC MMWR)

 

Abstract

In the United States, annual influenza vaccination has been recommended for all persons aged ≥6 months, including during the 2025–26 season. Interim influenza vaccine effectiveness (VE) estimates were calculated for patients with acute respiratory illness–associated outpatient visits and hospitalizations from three U.S. respiratory virus VE networks during the 2025–26 influenza season, using a test-negative case-control design. Among children and adolescents aged <18 years, VE was 38%–41% against influenza outpatient visits and 41% against influenza-associated hospitalization. Among adults aged ≥18 years, VE was 22%–34% against influenza outpatient visits and 30% against influenza-associated hospitalization. Among children and adolescents, VE against influenza A ranged from 37% (against outpatient visits) to 42% (against hospitalization) across settings; among adults, VE against influenza A ranged from 30% (against hospitalization) to 34% (against outpatient visits) across settings. Among children and adolescents, VE against influenza A(H3N2)–associated outpatient visits was 35% and against influenza A(H3N2)–associated hospitalization was 38%. VE against influenza B outpatient visits ranged from 45%–71% among children and adolescents and was 63% among adults. Other estimates of VE were not statistically significant or were not reportable. Although interim influenza VE is lower during the 2025–26 influenza season than it was during recent influenza seasons, these findings demonstrate that influenza vaccination still provides protection against influenza. CDC recommends influenza vaccination; U.S. influenza vaccines remain available for persons aged ≥6 months.

Source: 

Link: http://dx.doi.org/10.15585/mmwr.mm7509a2

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Identification of a Key #Hemagglutinin #Mutation Mediating #Antibody Escape in #Influenza #H1N1pdm09 Viruses

 

Abstract

Background: 

The H1N1 influenza A virus evades host immunity through continuous antigenic drift, posing a significant challenge to broad-spectrum neutralizing antibody therapies. This study aims to systematically evaluate the neutralizing capacity of the broad-spectrum antibody C12H5 against H1N1 strains from different eras and identify key immune escape mutation sites. 

Methods: 

Three representative H1N1 virus strains from 2009, 2018, and 2023 were selected. An antigen–antibody binding prediction model based on the ESM-2 large language model was constructed by integrating 48,762 GISAID sequence data and deep mutation scanning data from the Bloom laboratory. Candidate escape sites were screened using SHAP (SHapley Additive exPlanations) value analysis. Mutant viruses were constructed via reverse genetics, and their neutralizing capacity and replication fitness were validated through hemagglutination inhibition assays, microneutralization assays, and viral growth kinetics analysis. 

Results: 

Machine learning scoring identified five potential escape sites, with K147 exhibiting the highest overall score (0.92). SHAP analysis revealed that the K147 site within the HA protein’s 130-loop region received the highest importance score (0.28), significantly surpassing other candidate sites. Experimental validation revealed that the K147N mutation reduced neutralizing potency against C12H5 by 8-fold (from 1:1024 to 1:128) and approximately 6-fold in microneutralization assays (from 8.3 log2 to 5.7 log2), while exhibiting a replication advantage in MDCK cells. Microneutralization assays further confirmed an approximately 6-fold reduction in neutralization sensitivity. Structural analysis indicated that K147 is located at the periphery of the HA receptor-binding domain, immediately adjacent to the receptor-binding site. 

Conclusions: 

K147N is identified as the critical mutation mediating C12H5 immune escape, and this mutation has emerged in 2023 circulating strains. This study provides important molecular targets and early warning mechanisms for broad-spectrum antibody optimization and influenza vaccine updates.

Source: 

Link: https://www.mdpi.com/1999-4915/18/3/349

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Structures of #Marburgvirus #glycoprotein and its complex with NPC1 #receptor

 

Abstract

Marburgviruses (MBVs) cause severe haemorrhagic fever with higher fatality rates than Ebola virus (EBOV). Here we show that the MBV glycoprotein (GP) mediates viral entry more efficiently than EBOV GP. Using cryo-EM, we determined structures of MBV GP in three states: (1) unbound; (2) bound to its endosomal receptor NPC1; and (3) complexed with a neutralizing nanobody. The glycan cap shields the receptor-binding site from NPC1 but only partially from the nanobody, enabling limited immune evasion. After glycan cap cleavage, NPC1 binds to MBV GP in a distinct orientation compared with EBOV GP, providing an additional anchor and enhancing receptor affinity. NPC1 engagement also induces substantial conformational changes in MBV GP, probably facilitating membrane fusion. Furthermore, MBV GP is susceptible to the neutralizing nanobody, which mimics NPC1 at the receptor-binding site. Together, our findings reveal MBV GP as a highly efficient entry mediator and suggest structural mechanisms that may contribute to its enhanced entry efficiency.

Source: Nature, https://www.nature.com/

Link: https://www.nature.com/articles/s41586-026-10240-0

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A #clinical #SARS-CoV-2 #Mpro #inhibitor blocks replication of multiple #enteroviruses and confers oral in vivo protection in animal models

 

Abstract

Enteroviruses, which belong to the family Picornaviridae, cause hand, foot, and mouth disease (HFMD), respiratory symptoms, and severe neurological complications in children. Since vaccines cannot provide cross-protection against different serotypes of enteroviruses, the development of broad-spectrum anti-enteroviral drugs is imperative. The viral 3C protease (3Cpro), which is essential for polyprotein processing represents a validated target for therapeutic intervention. Importantly, enterovirus 3Cpro shares conserved structural and catalytic features with coronavirus main protease (Mpro, also known as 3C-like protease, 3CLpro), providing a rationale for cross-target inhibitor repurposing. Through targeted screening of peptidomimetic protease inhibitors, a clinical-stage SARS-CoV-2 Mpro inhibitor was identified as a potent inhibitor of enterovirus A71 (EV71) 3Cpro. Bofutrelvir displayed nanomolar antiviral activity in multiple cell lines and demonstrated broad-spectrum efficacy against several enteroviruses including coxsackievirus B5, coxsackievirus A16 (CA16) and echovirus 11. In EV71 infected neonatal mice, intraperitoneal administration of bofutrelvir markedly reduced viral loads in brain, spinal cord, and muscle, alleviated clinical symptoms, and suppressed tissue inflammation. Oral administration of bofutrelvir also provided therapeutic benefits in neonatal mice models of both EV71 and CA16. Crystallographic analysis revealed that bofutrelvir binds in the conserved substrate-binding cleft of EV71 3Cpro, elucidating its molecular mechanism of inhibition. These findings identify bofutrelvir as a broad-spectrum peptidomimetic 3Cpro inhibitor with strong antiviral efficacy against enteroviruses and highlight its potential for repurposing as a promising antiviral candidate for the treatment of enteroviral infections.

Source: 

Link: https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014051

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Defining the transmissible dose 50% for two #pandemic #influenza viruses in #ferrets

 

ABSTRACT

Ferrets are widely used to model airborne transmission of influenza viruses in humans. Airborne transmission is evaluated by infecting donor ferrets with a high virus dose and monitoring transmission to contact animals sharing the same airspace. Humans can be infected with a broad range of influenza virus doses. Therefore, we evaluated the relationship between inoculation dose and transmission for two pandemic influenza viruses in ferrets. Donor ferrets were inoculated with 100 to 106 tissue culture infectious dose 50 (TCID50) of the 2009 pandemic H1N1 or 1968 pandemic H3N2 virus and were then paired with respiratory contacts. Using the proportion of donors that became infected across virus doses, we calculated the infectious dose 50 (ID50). Subsequently, by comparing the proportion of contacts that became infected, we calculated the transmissible dose 50% (TD50): the donor inoculation dose that resulted in transmission to 50% of contacts. For the 2009 pandemic H1N1 virus, the ID50 and TD50 were equivalent at <1 TCID50. However, for the 1968 pandemic H3N2 virus, the ID50 and TD50 were 100.5 and 104.08 TCID50 (95% CI: 102.34–105.82), respectively. The increased TD50 for the H3N2 virus was associated with significant reductions in peak viral titers and viral shedding in donors over decreasing virus inoculation doses. Collectively, these studies define a new measure of transmission that permits comparisons of transmissibility between viral strains and subtypes in ferrets. We show that the 1968 pandemic H3N2 virus has a higher TD50 and reduced transmissibility in ferrets relative to the 2009 pandemic H1N1 virus.

Source: 

Link: https://journals.asm.org/doi/full/10.1128/jvi.01635-25?af=R

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{#Iran} #Conflict deepens #health #crisis across Middle East, #WHO says (March 11 '26)

 

More than ten days into the latest escalation of conflict in the Middle East, health systems across the Region are coming under strain as injuries and displacement rise, attacks on health care continue, and public health risks increase.

National health authorities in Iran report more than 1300 deaths and 9000 injuries, and in Lebanon report at least 570 deaths and more than 1400 injuries. In Israel, authorities report 15 deaths and 2142 injuries.

At the same time, the conflict is affecting the very services meant to save lives. 

In Iran, WHO has verified 18 attacks on health care since 28 February, resulting in 8 deaths among health workers. 

Over the same period in Lebanon, 25 attacks on health care have resulted in 16 deaths and 29 injuries. These attacks not only cost lives but deprive communities of care when they need it most. 

Health workers, patients and health facilities must always be protected under international humanitarian law.

Beyond the immediate impact, the conflict is creating wider public health risks. 

Current estimates indicate more than 100 000 people in Iran have relocated to other areas of the country due to insecurity, and up to 700 000 people have been internally displaced in Lebanon, with many in crowded collective shelters under deteriorating public health conditions, with limited access to safe water, sanitation and hygiene. These conditions increase the risk of respiratory infections, diarrhoeal diseases, and other communicable illnesses, especially for the most vulnerable populations, such as women and children.

Environmental hazards are also a raising concern. In Iran, petroleum fires and smoke from damaged infrastructure exposed nearby communities to toxic pollutants that potentially cause breathing problems, eye and skin irritation, and contaminated water and food sources.

Access to health services is becoming increasingly constrained across several countries. 

In Lebanon, 49 primary health-care centres and five hospitals have shut following evacuation orders issued by Israel’s military, reducing the availability of essential services as medical needs rise.

In the occupied Palestinian territory, increased movement restrictions and checkpoint closures are delaying ambulance and mobile clinics’ access across several governorates in the West Bank. 

In Gaza, medical evacuations remain suspended since 28 February, while hospitals continue to operate under strain amid ongoing shortages of medicines, medical supplies and fuel, which is being rationed to prioritize essential health services such as emergency and trauma care, maternal and neonatal services, and management of communicable diseases.

Temporary airspace restrictions have disrupted the movement of medical supplies from WHO’s global logistics hub in Dubai. 

More than 50 emergency supply requests, intended to benefit over 1.5 million people across 25 countries, are affected, resulting in significant backlogs. 

Current priority shipments include supplies planned for Al Arish, Egypt, to support the Gaza response, as well as Lebanon and Afghanistan. The first shipment, containing cholera response supplies for Mozambique, is expected to depart from the hub in the coming week.

The escalation comes at a time when humanitarian needs in the Eastern Mediterranean Region were already among the highest in the world. 

Across the Region, 115 million people require humanitarian assistance – almost half of all people in need globally – while humanitarian health emergency appeals remain 70% underfunded.

Without protection for health care, sustained humanitarian access and stronger financial and operational support for the humanitarian health response, the strain on vulnerable populations and already fragile health systems will continue to grow.

WHO calls on all parties to protect civilians and health care, ensure unimpeded and sustained humanitarian access, and pursue de-escalation of the conflict so communities can begin to recover and move towards peace.

Source: 

Link: https://www.who.int/news/item/11-03-2026-conflict-deepens-health-crisis-across-middle-east--who-says

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Post-discharge #sequelae of #Lassa fever #survivors in #Nigeria: an analysis of the LASCOPE prospective cohort

 

Summary

Background

Lassa fever is one of the most important viral haemorrhagic fevers, yet post-discharge sequelae remain inadequately characterised. Previous studies have been limited by small sample sizes and unsystematic assessments. We aimed to describe post-discharge sequelae in Lassa fever survivors and explore the effect of disease severity on sequelae patterns.

Methods

LASCOPE was a prospective study of patients with PCR-confirmed Lassa fever hospitalised at Federal Medical Centre Owo, Owo, Nigeria, between April 23, 2018, and Feb 17, 2023. All patients who provided informed consent were included, with no age restriction. Severe disease was defined as the presence of at least one of the following during the acute phase: National Early Warning Score version 2 score of 7 or higher, Kidney Disease Improving Global Outcomes stage 2 or higher, or Lassa virus PCR Ct value of less than 25. At hospital discharge, follow-up of survivors was planned for day 60 after admission, or before that, based on medical need. A systematic symptom assessment was done at each visit. The main outcome was clinical remission, defined as complete absence of symptoms. Other outcomes were post-discharge death, symptom incidence, and prevalence of symptoms over time. Subgroup analyses were performed by age group (children aged <18 years or adults aged ≥18 years) and disease severity (severe or not severe).

Findings

Of 882 survivors (median age 32 years [IQR 22–46], 459 [52%] female and 423 [48%] male), post-discharge data were available for 807 (91%), with a total of 2603 person-months of follow-up. For three of 807 survivors with post-discharge information, only the vital status was collected. 736 (91%) of 807 reached clinical remission, with a median time to clinical remission of 19 days (95% CI 16–23) post discharge. The most frequently reported symptoms were asthenia (158 [20%] of 804), headache (148 [18%]), and post-exertional malaise (123 [15%]). Hearing symptoms were reported by only 17 (2%) of 804 survivors, which was substantially lower than previous studies. Disease severity did not affect time to remission. Six (1%) survivors died after hospital discharge.

Interpretation

Patient-reported symptoms suggest good recovery with few hearing or neurosensory disorders in most survivors of Lassa fever. Future research would benefit from extended follow-up periods and standardised diagnostic assessments, including objective audiometry, to further characterise the full spectrum of post-Lassa fever complications.

Funding

Institut National de la Santé et de la Recherche Médicale, University of Oxford, EU, UK Department for International Development, Wellcome Trust, French Ministry of Foreign Affairs, Agence Nationale de Recherches sur le SIDA et les Hépatites Virales, and French National Research Institute for Sustainable Development.

Source: 

Link: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(26)00057-5/abstract?rss=yes

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A newly emergent N1 #neuraminidase associated with clade 2.3.4.4b highly pathogenic avian #influenza #H5 viruses in North #America

 

Abstract

We investigated the evolutionary history of the newly emergent neuraminidase (am4N1) associated with the D1.1 and D1.2 genotypes of highly pathogenic avian influenza A(H5N1) viruses in North America. Phylogenetic inference places am4N1 in a sister clade to Eurasian avian, swine, and human A(H1N1)pdm09 viruses and distinct from 1918, pre-2009 human seasonal, and classical swine A(H1N1) lineages. Am4N1 descends from diverse avian N1 genes endemic to the Americas. Phylodynamic analysis indicates a monophyletic am4N1 lineage with numerous introductions of viruses carrying the am4N1 gene likely originating from western Canada into the United States during emergence of the D1.1 and D1.2 genotypes. The lineage has diversified and accumulated deletions in the stalk domain. Despite amino acid divergence, structural modeling shows conserved neuraminidase architecture in the globular head. Given its distinct ancestry and amino acid sequence, further studies are needed to assess cross-reactivity of antibodies from prior human A(H1N1)pdm09 infections.

Competing Interest Statement

The authors have declared no competing interest.

Funding Statement

This study did not receive any external funding.

Source: 

Link: https://www.medrxiv.org/content/10.64898/2026.03.09.26347929v1

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#Chile - #Influenza A #H5N1 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

{Valparaíso} The birds shared a pond with wild birds. All birds were culled and buried on the property under strict biosecurity protocols. Cleaning and disinfection measures are being carried out.

Source: 

Link: https://wahis.woah.org/#/in-review/7357

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Deep #earthquake off the #coast of #Campania, ML 5.9, March 10, 2026 (INGV, edited)

 

{Excerpts}

On March 10, 2026, at 12:03 AM Italian time, a magnitude 5.9 earthquake occurred off the coast of Campania. 

The seismic event occurred at an  extremely deep depth , approximately  414 km , well below the common seismogenic depths of Italian earthquakes, which predominantly occur in the upper crust.

This deep event, quite rare for this geographical area, can be traced back to a geological process typical of the southern Tyrrhenian Sea  due to the presence in the Earth's mantle of a " slab " of oceanic lithosphere that has been sinking for several million years beneath the Tyrrhenian Sea.

This phenomenon is accompanied by  frequent seismicity along the Calabrian and Sicilian coasts – less frequent off the Campanian coast – , with earthquakes that in the last 40 years have reached  magnitude ML 5.8 on 28 October 2016 ,  at a depth  of  481 km ,  and magnitude Mw 5.8 on 29 October 2006,  at a depth  of  221 km . 

Another earthquake with a magnitude greater than 5 occurred on 3 November 2010, ML 5.4, at a depth of 506 km, and a significant deep earthquake of magnitude ML 4.2  occurred on the night between  26 and 27 October 2023 off the Sorrento Peninsula (province of Naples).

The strongest known deep earthquake in the area occurred on December 27, 1978, with a magnitude of 5.9 , at a  depth of 392 km off the coast of Gaeta (LT). 

In addition to this event, a 1951 study describes a very strong deep earthquake in the Tyrrhenian Sea in 1938 with an estimated magnitude between 6.8 and 7.1 ! One of the strongest earthquakes in our historical catalog.

Fortunately, in these cases, the great depth causes a strong attenuation of the seismic waves and therefore a lesser impact on the territory.

The earthquake was felt throughout Italy. In fact, the preliminary map of macroseismic tremors, continuously updated (1:23 a.m. Italian time), obtained from approximately 130 questionnaires sent to the website " Did you feel the earthquake? " shows tremors up to  grade III-IV MCS .

This work is licensed under a  Creative Commons Attribution-NoDerivatives 4.0 International License.

Source: 

Link: https://ingvterremoti.com/2026/03/10/terremoto-profondo-al-largo-delle-coste-campane-ml-5-9-10-marzo-2026/

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Novel #Reassortant #H5N2 Highly Pathogenic Avian #Influenza Viruses from Backyard #Poultry in #Mexico

 

Abstract

Highly pathogenic influenza A viruses of the H5 subtype continue to diversify worldwide through mutation and genetic reassortment, generating novel variants with unpredictable consequences under the One Health approach. Between 2024 and 2025, five outbreaks of avian influenza A viruses were detected in backyard poultry across Michoacán, Estado de México, and Ciudad de México. We conducted molecular and genetic characterization of five highly pathogenic H5N2 viruses isolated from these events. All cases tested positive for influenza A virus and the H5 hemagglutinin, exhibiting high pathogenicity with intravenous pathogenicity index values ranging from 2.88 to 3.0. Whole-genome sequencing revealed novel reassortants containing hemagglutinin from Eurasian H5N1 clade 2.3.4.4b and neuraminidase from the endemic Mexican H5N2 lineage. The viral genome of the isolate from Michoacán contained six segments derived from Eurasian H5N1 viruses introduced into North America in 2021–2022, while nucleoprotein and neuraminidase originated from Mexican H5N2 viruses. In contrast, viruses from Estado de México and Ciudad de México contained five H5N1-derived segments and incorporated polymerase basic protein 1, nucleoprotein, and neuraminidase from low-pathogenic H5N2 viruses circulating in 2024. Phylogenetic analyses confirmed the emergence of a distinct H5N2 Mexican sublineage, providing evidence of active viral reassortment and local evolutionary processes in Mexico.

Source: 

Link: https://www.mdpi.com/1999-4915/18/3/337

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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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