ETIDIOH - NEW

  Abstract Background   Infection of backyard and poultry with low pathogenicity avian influenza LPAI A(H5N2) viruses has occurred in Mexico since 1994, and the first human infection caused by this influenza virus was detected in 2024 . Since its emergence in the Americas , frequent reassortments between high pathogenicity avian influenza HPAI A(H5N1) and LPAI viruses has occurred. In September 2025 , the Instituto Nacional de Enfermedades Respiratorias of Mexico City identified an unsubtypeable influenza A virus infection in a young adult patient later determined to be a reassortant HPAI (H5N2) virus with a clade 2.3.4.4b HA .  Methods   We analyzed clinical and epidemiologic data from this patient. Respiratory samples were tested for influenza RT-qPCR assays . Genomic sequence and phylogenetics analyses were performed to provisionally assign a new genotype to the novel HPAI A(H5N2) reassortant virus.  Results   The patient presented with fever and tachypn...

  ABSTRACT The evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in antigenically distinct variants that challenge vaccine-induced immunity. The KP.2 monovalent mRNA vaccine was deployed in 2024 to address immune escape by emerging SARS-CoV-2 subvariants . We assessed neutralizing antibody responses in 56 adults with varied exposure histories following KP.2 vaccination against emerging variants including LP.8.1, LF.7.1, NB.1.8.1, XFG, and BA.3.2 . While KP.2 vaccination enhanced neutralization against homologous variants, substantial reductions in neutralizing activity were observed against emerging Omicron variants across all exposure groups. Exposure history showed some influence on neutralization breadth , with self-reported vaccination-only participants exhibiting better cross-neutralization compared to individuals with hybrid immunity . Antigenic cartography revealed substantial antigenic distances between KP.2 and emerging variants, highli...

  Abstract The membrane (M) protein of coronaviruses is essential for maintaining structural integrity during membrane virion budding and viral pathogenesis . Given its high conservation in lineages within the betacoronavirus genus , such as sarbecoviruses , the M protein presents as an attractive therapeutic target ; however, developing broad-spectrum antivirals targeting coronaviruses such as MERS-CoV is challenging due to lower sequence conservation and limited structural information available beyond that of the SARS-CoV-2 M protein . In this study, we report 3-3.2 Å resolution structures of MERS-CoV M protein, engineered with a SARS-CoV-2-like antibody interface, representing the first human merbecovirus M protein structure , and SARS-CoV M protein structures, with and without a previously identified SARS-CoV-2 M protein inhibitor, JNJ-9676. We highlight the structural differences between the MERS-CoV, SARS-CoV and SARS-CoV-2 M proteins, and present insights into the conservati...

  {Summary} Confirmed Cases at National Level [National - Total Cases : 71 { +1 }{§}] [Cases -  Exposure Source] -- 41 - Dairy Herds (Cattle){*} -- 24 - Poultry Farms and Culling Operations {*} -- 3 - Other Animal Exposure {†} -- 3 - Exposure Source Unknown {‡} Probable Cases at National Level [National - Total Cases : 7 {no change} ] [Cases -  Exposure Source] -- 1 - Dairy Herds (Cattle) {*} -- 5 - Poultry Farms and Culling Operations {*} --  0 - Other Animal Exposure {†} -- 1 - Exposure Source Unknown {‡} NOTE : One additional case was previously detected in a poultry worker in Colorado in 2022. Louisiana reported the first H5 bird flu death in the U.S. {*} Exposure Associated with Commercial Agriculture and Related Operations {†} Exposure was related to other animals such as backyard flocks, wild birds, or other mammals {‡} Exposure source was not able to be identified (...) {§} A case from Washington State, see more at:  https://doh.wa.gov/newsroom/grays-h...

  Abstract Three critically ill or fatal avian influenza A(H5N1) human infections have been reported in North America since November 2024 . Notably, all were infected with genotype D1.1 instead of B3.13, the dominant genotype before November 2024. Here, we demonstrated that D1.1 could replicate to higher titers in human nasal and airway organoid-derived transwell monolayers from 6 donors . D1.1 exhibited a better binding to α2,3- and α2,6-linked SA than B3.13. No significant differences in most inflammatory or antiviral cytokines/chemokines was observed. These observations suggest that D1.1 is better adapted to both the upper and lower human respiratory tract epithelium than B3.13. Source:  Link:  https://academic.oup.com/jid/advance-article/doi/10.1093/infdis/jiaf598/8341570#google_vignette ____

  ABSTRACT Passive administration of broadly neutralizing anti-influenza monoclonal antibodies (mAbs) before or after virus infection can prevent or alleviate disease. Unlike seasonal influenza, infection with zoonotic avian influenza viruses can lead to acute respiratory distress syndrome and high mortality in humans. Respiratory tract-targeting antibody delivery appears to be more clinically relevant and effective for zoonotic influenza treatment. In this study, the efficacy of an anti-H7N9 murine mAb 4B7 and its humanized form (chi4B7) against H7 subtype influenza viruses administered through the intranasal route was investigated in mice . 4B7 recognizes critical residues in the vestigial esterase domain and receptor-binding sites in the hemagglutinin of H7N9 virus . The antibody had cross-H7 binding, hemagglutination inhibition, and neutralizing activities. In particular, the dose of 4B7 required for prophylactic protection against H7N9 infection was significantly reduced in mi...

  Abstract The evolutionary divergence of the A(H5) hemagglutinin (HA) gene of high pathogenicity avian influenza (HPAI) viruses (A/goose/Guangdong/96 lineage) was analyzed by phylogenetic and average pairwise distance methods to identify clades that merit nomenclature updates . Based on this assessment, 12 new clade designations were recommended based on division of clade 2.3.2.1c and 2.3.4.4 viruses, which were reported in Africa, Antarctica, Asia, Europe, the Middle East, the Americas and Oceania since the most recent WHO/WOAH/FAO H5 Evolution Working Group update. Competing Interest Statement The authors have declared no competing interest. Source:  Link:  https://www.biorxiv.org/content/10.1101/2025.11.23.690055v1 ____