ETIDIOH - NEW

  Abstract Background West Nile Virus (WNV) is a zoonotic arbovirus maintained in a transmission cycle between Culex mosquitoes and birds , occasionally spilling over into humans. The impact of avian biodiversity on WNV circulation remains debated, with studies reporting both negative and positive correlations (dilution and amplification effects respectively) across different settings. In Europe, this relationship remains largely unexplored, particularly in regions with high WNV transmission, such as Emilia-Romagna in Northern Italy. Methods We explored the association between avian biodiversity and WNV circulation in Culex mosquitoes in Emilia-Romagna using 11 years (2013–2023) of entomological surveillance data paired with two avian data sources . We calculated avian biodiversity indices (Shannon’s, Simpson’s, and Chao2) from observation records from the Farmland Bird Index project and applied linear regression models to assess their relationship with WNV detection frequency. Mor...

  {Summary} Risk Statement   -- This Rapid Risk Assessment (RRA) evaluates the global public health risk posed by Nipah virus (NiV), considering the distinct epidemiological profiles of  - i) enzootic countries , where recurrent zoonotic spillover and limited human‑to‑human transmission continue to occur, and  - ii) non‑enzootic regions , where the risk remains primarily associated with infected travellers or importation of infected livestock.  -- The assessment considers the ecological and seasonal drivers of spillover , the constrained efficiency of human‑to‑human transmission , and the capacity of health and community systems to detect, confirm, and rapidly contain outbreaks.  -- Given that NiV has not demonstrated sustained transmission beyond outbreak settings and no human cases have ever been reported outside Asia , the global risk is largely determined by localized outbreaks in endemic areas and the very low likelihood of onward transmission fol...

  Abstract Wastewater monitoring enables non-invasive, population-scale tracking of community infections independent of healthcare-seeking behavior and clinical diagnosis. Metagenomic sequencing extends this capability by enabling broad, pathogen-agnostic detection, genomic characterization , and identification of novel or unexpected threats . Here, we present data from CASPER (the Coalition for Agnostic Sequencing of Pathogens from Environmental Reservoirs), a U.S.-based wastewater metagenomic sequencing network designed for deep, untargeted pathogen monitoring at national scale. This release includes 1,206 samples collected between December 2023 and December 2025 from 27 sites across nine states , covering 13 million people . Deep sequencing (~1 billion read pairs per sample) generated 1.2 trillion read pairs ( 347 terabases ), enabling detection of even rare taxa , with CASPER representing 66% of all untargeted wastewater sequencing data currently available on the NCBI Sequence ...

  {Excerpt} (...) COVID-19 current vaccine safety status and insights   -- Since 2021, GACVS has regularly reviewed the safety of COVID-19 vaccines , including through global pharmacovigilance data and dedicated reviews of myocarditis, pregnancy outcomes and other adverse events of special interest (AESI).  -- The most recent updates reaffirmed that the benefits of vaccination outweigh the risks across all groups and advised continued monitoring for younger males and follow-up of persons who have reported vaccine-associated myocarditis .  -- Many individuals have received three or more doses of COVID-19 vaccine.  -- Some adverse events – such as myocarditis – seem to occur mainly after the second dose of mRNA COVID- 19 vaccines.  -- However, the outcomes were less severe in persons who developed myocarditis after vaccination compared to those unvaccinated and following infections, including SARS- CoV-2.  -- Also, children under six months of age seem t...

  {Excerpt} Time Period: February 22, 2026 - February 28, 2026 -- H5 Detection :  9 site(s) ( 2.0% ) -- No Detection :  443 site(s) ( 98.0% ) -- No samples in last week :  147 site(s) (...) Source:  Link:  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

  Backyard poultry in the Bijelo Polje Region. Source:  Link:  https://wahis.woah.org/#/in-review/7334 ____

  Abstract The development of broadly protective and dose-sparing influenza vaccines remains a critical challenge , particularly for zoonotic H5N1 strains with pandemic potential . This study evaluates BECC470s, a synthetic TLR4 adjuvant , for its ability to enhance the immunogenicity and protective efficacy of recombinant H5 hemagglutinin (rHA) vaccination in murine models . BECC470s-adjuvanted rHA elicited robust IgG1/IgG2a antibody responses and complete survival following homologous 2004 H5N1 challenge in a prime–boost model . Although BECC470s broadened antibody binding to both variable HA head and conserved stalk domains by ELISA, functional neutralizing antibody responses were restricted to the matched 2004 H5N1 isolate, with no detectable neutralization of H5N1 viruses isolated in 2022 or 2024. These data indicate that BECC470s enhances the magnitude and apparent breadth of binding antibody responses while maintaining strain-specific neutralizing activity, supporting its po...

{England, North Yorkshire} 22.7k commercial pheasant rearing premises. Samples taken were positive for HPAI H5N1. Birds presented clinical signs prior to testing. Source:  Link:  https://wahis.woah.org/#/in-review/7337 ____

  Fourteen Coscoroba Swans in the Región de Valparaíso, Comuna Santo Domingo. Source:  Link:  https://wahis.woah.org/#/in-review/7336 ____

  Abstract Transmission of highly pathogenic avian influenza from H5 clade 2.3.4.4b has expanded in recent years to infect large populations of birds and mammals , heightening the risk of a human pandemic . Influenza viruses that are adapted to transmission in birds and a variety of mammals tend to have a less stable hemagglutinin (HA) than seasonal influenza viruses, enabling membrane fusion at comparatively higher pH levels . Here, we combined five mutations in the H5 HA that increased its melting temperature and promoted stable closure of the HA trimer . Structural analysis by cryo–electron microscopy revealed that the stabilizing mutations create several new hydrophobic interactions while maintaining the local HA structure . We found that vaccinating mice with stabilized H5 HA immunogens resulted in higher hemagglutination inhibition and neutralization titers than nonstabilized comparators. Epitope mapping of vaccine-elicited polyclonal antibody responses using negative-stain e...

  Abstract Highly pathogenic avian influenza virus of the H5N1 subtype has been infecting U.S. dairy cattle and spreading among dairy operations since March 2024. H5N1 surveillance systems for dairies are needed, but information on whether environmental sampling can inform these systems is lacking. To guide a surveillance framework , we determined the environmental sites with Influenza A virus (IAV) detection on H5N1-affected dairies (n = 25) in four states (California, Colorado, Michigan, and Ohio) and explored sample characteristics that may have influenced detection. A total of 581 samples from dairy environmental sites were characterized for IAV RNA via rRT-PCR, and classified into six categories . A total of 94 samples (16.2%) had IAV detected, and the Ct values measured from these samples were typically higher than those measured in bulk tank milk from a subset of sampled herds. A majority of IAV detections were made from the following site categories: milking equipment/perso...

  Abstract Highly pathogenic avian influenza (HPAI) clade 2.3.4.4b H5N1 virus has recently emerged in dairy cattle in the United States . The virus replicates primarily in the mammary gland of infected cattle, leading to dramatic reductions in milk production . It is thought that the virus transmits from animal to animal through viral shedding in milk , and therefore, vaccines that decrease the amount of virus in milk can potentially limit the current outbreak and reduce the risk of H5N1 spillover into humans . Here, we assess the immunogenicity and efficacy of a clade 2.3.4.4b H5 mRNA-LNP vaccine in lactating dairy cows . We found that the H5 mRNA-LNP vaccine elicited robust antibody responses in sera and milk and significantly reduced viral replication and disease caused by clade 2.3.4.4b H5N1 intramammary infection. Competing Interest Statement S.E.H. and D.W. are co-inventors on patents that describe the use of nucleoside-modified mRNA as a platform to deliver therapeutic prote...

  Abstract Dairy cattle have emerged as a prolific amplifying host for highly pathogenic avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b and a new source for cross-species and zoonotic transmission . Independent introductions of H5N1 with unclear exposure routes have been reported in several dairy herds across the U.S. These events escalate the pandemic potential of HPAIV H5N1 as transmission within and between mammalian species present opportunities for mammalian adapted H5N1 viruses to emerge . Although more than 1000 herds have been infected, bovine H5N1 influenza virus pathogenesis, transmission, and evolution in dairy cattle remains not well characterized. Working with H5N1-infected lactating cattle in high containment has been a major challenge due to the required infrastructure and logistics associated with housing, husbandry, and waste management for this model. Thus, developing alternative bovine models that maintain biological relevance while reducing operational comple...

  Abstract Antibodies to the influenza hemagglutinin protein (HA) confer the strongest protection against infection . Immunity elicited by endemic, seasonal, human viruses is correlated with diminished disease severity and death caused by antigenically novel viruses. Antibodies to the HA head interface are broadly protective and abundant in human serologic and memory repertoires . Notably, few head interface antibodies from H5 naive donors are reported to bind H5 HAs . We find head interface antibodies engage a wide range of H5 isolates but fail to engage most isolates from the goose Guangdong (GsGd) lineage . We identify a single substitution, P221S, largely dictates antibody binding. Phylogenetic analysis indicates that P221S arose in a Chinese avian reservoir by the year 2000 . Descendants of these viruses have caused the current global panzootic and have achieved sustained mammal-mammal transmission in farmed and wild mammals. Our findings demonstrate that viral evolution in no...

  {4 March 2026, excerpts} The 44th meeting of the Emergency Committee under the International Health Regulations (IHR or Regulations) on the international spread of poliovirus was convened by the WHO Director-General on 14 January 2026 with eight out of nine Committee members and the adviser meeting via video conference with affected countries, supported by the WHO Secretariat.  The Emergency Committee reviewed the latest epidemiological data on wild poliovirus type 1 (WPV1) and circulating vaccine-derived polioviruses (cVDPV) in the context of the global targets to interrupt endemic WPV1 transmission in 2026 and to stop cVDPV2 outbreaks by 2028 with subsequent certification of WPV1 eradication and cVDPV2 elimination.  Technical updates were received about the situation in the following countries :  - Afghanistan,  - Angola,  - Germany,  - Lao People’s Democratic Republic,  - Namibia,  - Pakistan and  - Papua New Guinea . Amendments to ...

  Abstract Influenza virus mRNAs are stable and competent for nuclear export and translation because they receive a 5′ cap(1) structure in a process called cap snatching 1. During cap snatching, the viral RNA-dependent RNA polymerase (FluPol) binds to host RNA polymerase II (Pol II) and the emerging transcript2,3. The FluPol endonuclease then cleaves a capped RNA fragment that subsequently acts as a primer for the transcription of viral genes 4,5. Here we present the cryogenic electron microscopy structure of FluPol bound to a transcribing Pol II in complex with the elongation factor DSIF in the pre-cleavage state. The structure shows that FluPol directly interacts with both Pol II and DSIF , positioning the FluPol endonuclease domain near the RNA exit channel of Pol II . These interactions are important for the endonuclease activity of FluPol and FluPol activity in cells. A second structure , trapped after cap snatching, shows that the cleaved capped RNA rearranges within FluPol, ...

  A poultry farm in Bihar State. Source:  Link:  https://wahis.woah.org/#/in-review/7319 ____

  Abstract Middle East respiratory syndrome coronavirus (MERS-CoV) is assessed to have high pandemic risk , and dromedary camels are the source of zoonotic spillover . More than 75% of MERS-CoV–infected dromedary camels are found in Africa , but no zoonotic disease has been reported from Africa where there is little awareness of MERS-CoV as a potential cause of respiratory disease . Antibody responses are a poor indicator of mild infection . We found that 47 of 60 (78%) dromedary camel abattoir workers in Kano, Nigeria, had MERS-CoV–specific T-cell responses while none of 18 controls did, suggesting that zoonotic infection is common in camel-exposed individuals in Africa. Source:  Link:  https://academic.oup.com/jid/advance-article-abstract/doi/10.1093/infdis/jiag095/8504072?redirectedFrom=fulltext ____

  Abstract In China, low pathogenic avian influenza (LPAI) H3N8 virus is widespread among chickens and has recently caused three zoonotic infections , with the last one in 2023 being fatal . Here we evaluated the relative pandemic risk of this 2023 zoonotic H3N8 influenza virus , utilizing our previously published decision tree . Serological analysis indicated that a large proportion of the human population does not have any cross-neutralizing antibodies against this H3N8 strain. LPAI H3N8 displayed a dual affinity for α2–3 and α2–6 sialic acids and replicated efficiently in human bronchial epithelial cells . Furthermore, we observed H3N8 transmission via direct contact but not aerosols to ferrets with pre-existing H3N2 immunity . Although pre-existing H3N2 immunity resulted in a shortened disease course in ferrets, it did not reduce disease severity or replication in the respiratory tract. This study suggests that this zoonotic H3N8 strain has moderate pandemic potential and empha...

  Abstract For nearly 30 years, Goose/Guangdong-derived highly pathogenic avian influenza H5N1 viruses have posed significant risks to economic stability, food security, and public health . Virus evolution has resulted in various clades , including the panzootic subclade 2.3.4.4b, recognized for its pandemic potential . Here we present the potent in vitro activity of FNI9, a pan-influenza NA-inhibiting monoclonal antibody , against a range of pseudoparticles with NA spanning decades of H5N1 virus evolution . FNI9 also shows strong prophylactic protection in female mice against lethal challenges with H5N1 from clade 1 and 2.3.4.4b. Cryo-EM and molecular dynamics analysis reveal that FNI9 binds to 7 highly conserved H5N1 NA residues (R118, E119, D151, E228, E278, R293, and R368). In silico evolutionary escape profiling and machine learning predict low escapability, high fitness costs, and minimal spread likelihood for viral mutations that evade FNI9 binding. These findings support FN...